1. (20 points) In HW 1, you generated a random network. Now, you will generated a scale-free network using the Barabasi-Albert model that we discussed on 2nd Nov. Submit hardcopy of the program for 1(b).

1(a): Create a network with 4 nodes that are connected to each other i.e., a complete graph with 4 nodes and the degree for all is 3.

library("network")
library(igraph)
n<-4
p.<-1
g<-erdos.renyi.game(n,p.,type = c("gnp"),directed = FALSE,loops = FALSE)
plot.igraph(g)

g
## IGRAPH 157681e U--- 4 6 -- Erdos renyi (gnp) graph
## + attr: name (g/c), type (g/c), loops (g/l), p (g/n)
## + edges from 157681e:
## [1] 1--2 1--3 1--4 2--3 2--4 3--4

Number of nodes is 4 Number of links is 6

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g,v=V(g), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 3 3 3 3

Add a new node (the 5th one) to this existing network such that the new node randomly attaches to 3 nodes of the existing network with probabilities that are proportional to the degrees of the nodes already in the network. Make sure that there are no multiple edges (the same node must not be linked more than once). Now, you have a 5-node network. Update the degrees of all the nodes.

g5<-barabasi.game(5, power = 1, m = 3, out.dist = NULL, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g)
plot.igraph(g5)

g5
## IGRAPH 159d372 U--- 5 9 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/n), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 159d372:
## [1] 1--2 1--3 1--4 2--3 2--4 3--4 3--5 1--5 4--5

Number of nodes is 5 Number of links is 9

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g5,v=V(g5), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 4 3 4 4 3

Add the 6th node (with 3 links) in a similar fashion.

g6<-barabasi.game(6, power = 1, m = 3, out.dist = NULL, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g5)
plot.igraph(g6)

g6
## IGRAPH 1653475 U--- 6 12 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/n), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 1653475:
##  [1] 1--2 1--3 1--4 2--3 2--4 3--4 3--5 1--5 4--5 1--6 2--6 5--6

Number of nodes is 6 Number of links is 12

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g6,v=V(g6), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 5 4 4 4 4 3

Continue to add 5000 nodes. The final network has 5004 nodes with (6+15000) links. In the following graph, larger Nodes have a higher degree and are shown in the center.

g5004<-barabasi.game(5004, power = 1, m = 3, out.dist = NULL, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g6)
deg <- degree(g5004, mode="all")
l <- layout_with_fr(g5004)
l <- norm_coords(l, ymin=-15.3, ymax=15.3, xmin=-23, xmax=23)
par(mfrow=c(1,1), mar=c(0,0,0,0))
plot(g5004, rescale=F, layout=l*.07,vertex.label=NA,vertex.size=deg*.1,edge.width=.0000000000000000001,edge.curved=.1)

g5004
## IGRAPH 1676296 U--- 5004 15006 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/n), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 1676296:
##  [1]  1-- 2  1-- 3  1-- 4  2-- 3  2-- 4  3-- 4  3-- 5  1-- 5  4-- 5  1-- 6
## [11]  2-- 6  5-- 6  2-- 7  5-- 7  6-- 7  2-- 8  4-- 8  1-- 8  2-- 9  7-- 9
## [21]  5-- 9  5--10  2--10  7--10  3--11  6--11  2--11  2--12  6--12 10--12
## [31]  5--13  4--13 11--13  9--14  7--14  1--14 10--15  9--15  4--15  4--16
## [41]  2--16  3--16  1--17  5--17 11--17 12--18  7--18  1--18  2--19 12--19
## [51]  4--19 11--20 14--20  2--20 16--21 12--21 13--21  5--22 16--22  3--22
## [61]  5--23 10--23  2--23  4--24 12--24  5--24 21--25 23--25  3--25 10--26
## + ... omitted several edges

Number of nodes is 5004 Number of links is 15006

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g5004,v=V(g5004), mode = c("total"),loops = FALSE, normalized = FALSE)
##    [1] 130 137  89 109 150  48 117  67  73  63  61  54  65  41  56  24  56
##   [18]  48  51  12  25  39 100  28  24  24  24  27  32  22  25   5  62  36
##   [35]  17  26  37  11  20  34  18  34  32  20  51  14  35  17  36  42  25
##   [52]  31  32   7  25  32  33  21  18  25  13  23  24  48  14  24  56  37
##   [69]  56  37  29   9  25  17  13  27   5  44  43  56  25  31  37  25  10
##   [86]  22  22  14  17  21   7  23  57  24  20  35  19  10  29  31  26  19
##  [103]   9  13  19  16  16   9  15  30  21   5  17   7  11  18  16  28  37
##  [120]  13  20  12  17  12  16  13  24  21  10  15  12  11  13  26  14  15
##  [137]  15  23  28  20  25   8  20  17   8  13  22  21  11  16   9  25  10
##  [154]  21  26  27  14   9   7  35   7  24   6   7  12   9   5   6   7  16
##  [171]  17  17  24  26  16  16  28  17  15   5  16  24   8  16  15  12  16
##  [188]  20  33  19  15  11   9  11   6  25  13  18  18  17  25   8  10   5
##  [205]  17  12  10  24  12  21  18  13  12  10   6  19  17  15  18  11   6
##  [222]   8   7   6  22   7  21  20  25  10  12  16  15   7  23   6  23   8
##  [239]  21  14  18   5  18  10   7  15  10   5  12  31  14  48   6  22   8
##  [256]   7  14   6   3   7  18  13   9  18  15  10  10   6  18   8  11  16
##  [273]   8  15  15  12  22  17   9   7   7  15   8  11  17  21  21  26  25
##  [290]  23   8   8   7   9   6   7  27  15  12  20   8  13  14   9   9  11
##  [307]   4   4  16   7  26  12   7  14  17   4   8  17  13  10  11  19   7
##  [324]  16  18  16   6  23   7   8   7  13   6   6  13  13   4  13  16  10
##  [341]  10  10   6  10   8  12   7   9  12  27  12  13  12  10   9   8  18
##  [358]   9  10  12   5  14  15   8  10  10   6   9   6   7   4   7  11  13
##  [375]   7  12  12   9   4  10  16   7   8   7  17  21  15  13  12   7  20
##  [392]  13  12   6  12  12  13   5  12  10  11  11  12   4   3   5   5   6
##  [409]   8   8  12  10  22   7  12   9  12  11  13  17   8  15   8   8  15
##  [426]   7   9   8  16  10  13   9  19   8  11  16  23  15  10  11   6  14
##  [443]   6   8   9   7  12  15   9  13   5   8  11  18  12   6  11   9   7
##  [460]   7  12  16  14  10   7   8  11  12  11   8  12   7   7  11  12   9
##  [477]  12   8   8  11  28   8   7  12   5  13  10  12  18  11   8  10   9
##  [494]  14  12   6  13   5   7   3   5  10   8  10   7  12  15  10  19  13
##  [511]  10  10   5  15  16   6  11   5   8   5  14   3  12  16  13  10  10
##  [528]   6   8  10  13  11   4  14   6  16   6   6   4   5  12  12  11   9
##  [545]  17   5   8   6   5   8   9   9   5   8  12  15   8   7   4  12  10
##  [562]   7   6  13   7   7   7   6   7   9  11   5   7   7  15  12  15   7
##  [579]   7   7  11   6   9  10   9   8   9  13   5   7   5  17   9  12  12
##  [596]  11  10   8   9   8  10   9   6  10   7   8   5   7  10  11   9  10
##  [613]   5  19  12   6   9   5   7   9   6  10  11  12   5   7   8   7   7
##  [630]   9   7   9   4   8   7   9   6  11   3  10   9  13   7   9  14   8
##  [647]  10   7   8   8   8  14  11   7  13   5  10   8   6   7  11   3   7
##  [664]  13   3   8   5   6  10   6  22  10  10   4   6  13   8  11   4  11
##  [681]   6   8   7   8   9   9  10   9  10   7   9   8  12   8   7   9   9
##  [698]   7   5   6   5  11   5   9  15   6   6   9   6   6   9   7  11   9
##  [715]   4   4   8   7   3   9   6   8   6   5   6   5   4  13   5  10   9
##  [732]  14   7   8   9  10   4  14   7   8   3   4   6  15   4  12   5  14
##  [749]  20   6  13   9   3   6   7   9   6  11   6   9  12   6   7   5   6
##  [766]  12   6  13   7  12  12   3   5   5   8  15   6   5   9   4   4   5
##  [783]   7   6   5   4   4   6   8   7   8  11   9  11  13   8  11   5   8
##  [800]   4  10   8   6   5  14   5  12   9   8   9   7  10  12   7   6   9
##  [817]  12  13   5   6   4   8   7  10   5   4   8   7   5   9   7  15   9
##  [834]  10   4  11  11   7  18   3   3  11   8  13   6   6   4  14   7   4
##  [851]   9   5   6  21   6   8   9   4   5   9   4   8  10   6  10  10   5
##  [868]   7   6   8   8   9   6   4   4   8  12  11   8   9   6   4   5   6
##  [885]   8   8   9   5  10   7   6   6   6  12   4  10  15   3  11   5   3
##  [902]   6   7   4   4   6   6   8   8   3  13   4   8  13   5  11   9   8
##  [919]  10   4   5   8   8   5   5   6   5   9   7  12   7   5  11  12  11
##  [936]   7   8   6   7   8   8   4   6   6   6   5   5   8   8   5   8   6
##  [953]   6   5   7   6   4   4  13   5   6   4   6   3   4   7  13  11   7
##  [970]   6   7   9   6   6   6   4   7   7  10   8   8   4   4  10   9   7
##  [987]   6   8   7   6   5   3   3   6   7   6  12  10  11   8   8  11   6
## [1004]   7   6   6   6   8   6   8   5  13  10   3   8   5   9   4  10   8
## [1021]  11   3   6   8  12   4   5   5  12   6   3   8   8   6   4  10  11
## [1038]   8   5   6   9   6   7   6   8   6  11  10   6   3   7   8  11   5
## [1055]   6   7  12   5  10   8   5   3   6   8   7  10   7   6   3   7   6
## [1072]   8   6   6   4  11  10   3   7   7   6   8   6   8   7   9  10   7
## [1089]   9   6  10   4   3   5  10   6   4  10   6   6  10   4   6   9   6
## [1106]   4   6   3   9   5   7  10   5   6  12   3   5   4   6   6  14   7
## [1123]   6  12   3  10   6   7   4   5   8  11   7   8   4   4   7   5   5
## [1140]   7   5  11   7   7   6   5   5   4   6   9   9   6  10   8   4   8
## [1157]   6   9  10   7   5   8   6   5   7  12   3   8   5   5  15   3  10
## [1174]   3   5  11   7  10   8   8   6   3  10   6   5   4   6   8  13   5
## [1191]   5   5   3   5   3   6  12   5   3   4   3   5   7   9   9   7   4
## [1208]   8   6   3   7   7   7   5  11   3   6   6   6  14   8   5   4   3
## [1225]   4   6   5   6   5   5   7   4   7   7   7   5   6   8   6   3   5
## [1242]   5   5   5   8   3   4   4   9   6   5   8   6   8   4   9  10   5
## [1259]   5   4   6   5   7   9   6   8   5   5   9   4   9   5   5   3   6
## [1276]   5   4  10   7   5   5   7   7   5   8   4   5  10   5   6   3   6
## [1293]   5   6   8   4   6   9   4   4   4   8   7   5   7   7   8   4   7
## [1310]   7   7   3   8  10   5   4   4   5   8   4   4   4   5   4   5   7
## [1327]   6   4   4   4   4   7   9   7   7   6   3   7   4   9  11   8   4
## [1344]   9   5   8   4   4   5   4   7   5   7   6   6   6   4   3   7   9
## [1361]   6   4   4  12   4   7   5   9   6   4   6  11   6   6   4   6   4
## [1378]   5  12   5   8   3   5   3   4   4   4   5   6   6   4   4   6   6
## [1395]   4   5   6   8   8  10   5   3   5  10   8   5   7   3   8   5   9
## [1412]   4   3   5   3   4   8   9   8   5   4   5   9  10   5   5   6   5
## [1429]   3  12   6   3   3   6   7   6   5  14   9   7   4  11   5   3   6
## [1446]   7   8   5   7   6   5   5   4   4   6   8   6   6   4   9   4   4
## [1463]  18   4   6   7   6   7   7   7   8   7   3   4   5   5   6   5   5
## [1480]   5   6   6   4   6   4   6   3  12   5   5   9   5   6   3   7   6
## [1497]   7   7   8   3   3   4   4  13   6   9   6   9   5   4   3   4   3
## [1514]   5   3  11   4   9   4   4   5   6   3  11   5   5   6   7   3   4
## [1531]   4   5   8   5   9   5   6   4   6   5   7   5   8   7   5   7   3
## [1548]   5   4   4   8  11   6   5   4   5   4   8   4   5   4   3   7   4
## [1565]   3   5   7   4   5   4   5   6   4   9   4   3   6   6   8   8   3
## [1582]   5   8   3   6   3   5   9   4   8   8   5   6   5   3   7   4   4
## [1599]   5   6   6   5   5   8   8   5   3   4   7  10  10   6   5   9   6
## [1616]   3   6   9   8   5   5   4   5   6   8   5   6   7   5   3   4   6
## [1633]   6   6   3   4   9   4   7   3   6   6   7   4   6   3   4   7   4
## [1650]   5   6   8   6   5   4   7   3   5   9   7   7   5   4   4   4   5
## [1667]   5   5   4   6   4   4   3  10   7   3   6   6   6   3   6   4   6
## [1684]   4   6   7   5   4   5   4   8   6   5   3   5   4   7   3   3   9
## [1701]   6   3   3   6   6   4   5   7   4   4   5   4   5   5   3   6   5
## [1718]   5   5   5  10   6   5   7   4   6   3   5   3  10   4   7   5   7
## [1735]   3   5   4   4   5   4   6   4   6   7   5   9   6  10   7   3   3
## [1752]   7   7   4   4   5   5   6   5   3   6   4   5   5   3   6   7   3
## [1769]   5   6   3   3  10   6   6   4   8   5   6   3   4   4   3   4   7
## [1786]   6   7   6   8   4   4   3   6   9   3   4   5   4   4   4   6   8
## [1803]   5   7   5   5   3   4   6   4   6   5   4   6   3   4   6   4   4
## [1820]   3   8   4   5   4   4   5   4   4   5   5   4   4   6   6   7   4
## [1837]   5   6   5   4   4   4   5   6   8   5   8   9   4   3   4   4   4
## [1854]   5   4   3   3   4   4   6   5   5   5   5   4   5   8   5   6   5
## [1871]   3   7   4   6   4   3   7   6   8   4   6   3   5   5   3   4   5
## [1888]   4   6   9   3   5   3   4   5   5   3   3   7   7   6   4   5   3
## [1905]   4   7   4   6   4   4   8   5   5   3   3   6   5   3   7   4   6
## [1922]  11   8   3   3   4   7   5   3   6   8   6   7   6   5   8   4   4
## [1939]   3   6   4   4   4   6  10   3   3   3   5   3   4   5   6   7   4
## [1956]   3   9   6   9  10   4   6   3   7   5   6   3   4   4   5   4   5
## [1973]   7   5   6   7   6   5   5   5   6   7   5   8   4   3   5   8   4
## [1990]   3   5   5   7   4   4   3   5   5   5   4   4   6   3   5   9   4
## [2007]   7   6   6   5   3   3   5   7   3   3   4   4   5   6   6   6   3
## [2024]   3   3   7   9   3   3   4   5   7   5   5   6   3   4   4   4   4
## [2041]   4   5   4   4   5   3   3   5   3   7   5   5   4   7   3   9   5
## [2058]   5   6   3   3   3   3   8   4   5   6   3   4   3   8   8   4   4
## [2075]   5   3   4   4   5   7   5   6   4   4   5   6   7  11   6   3   8
## [2092]   5   4   4   4   6   3   3   6   4   5   4  10   4   4   5   3   4
## [2109]   9   8   4   6   5   3   3   4   4   3   3   6   4   4   3   7   5
## [2126]   3   3   5   5   6   7   3   3   5   3   5   9   8   3   5   6   7
## [2143]   4   4   5   4   5   6   6   4   6   3   5   7   6   7   5   3   3
## [2160]   3   6  13   6   7   4   5   9   3  10   3   4   7   6   4   7   3
## [2177]   4   5   5   7   3   6   4   3   4   6   3   5   3  12   6   4   5
## [2194]   4   4   4   5   6   4   4   4   4   3   4   5   3   4   3   5   3
## [2211]   4   5   5   6   6   3   5   4   4   4   4   4   4   3   3   6   3
## [2228]   4   6   5   3   3   3   5   3   3   3   5   3   4   6   6   9   6
## [2245]   3   3   6   3   6   7   7   3   5   6   6   4   6   5   4   6   6
## [2262]   3   4   4   4   4   5   3   8   3   5   5   3   4   4   3   3   5
## [2279]  10   4   3   8   4   4   4   3   8   3   5   6   4   6   4   4  10
## [2296]   3   4   3   4   4   6   3   3   4   6   3   5   5   4   8   5   4
## [2313]   7   3   3   7   6   3   4   6   3   6   3   3  11   6   8   5   4
## [2330]   4   5   5   6   4   6   6   5   3   5   5   3   5   5   4   3   4
## [2347]   7   7   3   6   3   6   4   3   3   3   7   6   4   4   3   6   5
## [2364]   4   4   4   3   4   6   4   3   6   3   4   7   5   7   5   3   3
## [2381]   4   6   4   7   7   5   4   5   4   5   3   4   4   6   3   3   6
## [2398]   3   4   3   4   5   3   3   4   9   4   3   4   5   3   6   4   6
## [2415]   4   4   4   6   4   7   3   8   6   4   6   4   5   4   3   3   6
## [2432]   4   5   4   8   3   6   4   4   4   4   4   7   8   5   7   3   3
## [2449]   4   3   3   8   3   4   5   4   3   5   4   6   5   5   3   6   4
## [2466]   5   3   3   3   5   4   5   5   4   3   3   5   4   6   6   3   7
## [2483]   4   3   6   5   4   5   5   5   3   4   3   3   4   7   3   4   7
## [2500]   6   6   5   8   4   5   3   5   4   7   4   4   4   3   4   3   3
## [2517]   3   5   3   7   3   5   3   6   5   4   6   4   4   5   4   6   4
## [2534]   3   8   3   4   5   3   6   3   3   5   6   3   8   4   4   3   4
## [2551]   4   5   6   6   3   8   4   6   3   3   7   3   3   6   4   4   4
## [2568]   5   4   3   4   3   5   5   5   5   3   3   3   3   3   5   4   5
## [2585]   4   4   5   6   4   5   7   3   4   6   3   3   3   4   4   4   6
## [2602]   6   3   4   3   3   4   6   4   7   3   5   3   4   5   5   4   6
## [2619]   5   4   4   5   4   4   4   4   9   3   5   5   5   3   3   3   3
## [2636]   4   3   4   4   3   4   3   3   5   3   5   4   4   5   4   5   6
## [2653]   3   3   3   6   4   3   5   5   4   3   4   4   4   3   5   3   3
## [2670]   4   4   3   4   3   4   4   3   5   4   3   3   4   4   3   3   4
## [2687]   3   4   5   6   4   4   3   4   3   3   4   4   4   5   6   8   3
## [2704]   3   3   4   5   4   3   4   5   3   4   4   3   3   3   3   4   5
## [2721]   3   5   3   6   6   5   3   6   3   3   4   4   3   6   6   4   4
## [2738]   4   3   4   3   6   5   4   3   5   4   3   5   3   3   3   4   3
## [2755]   5   4   6   4   3   4   4   3   5   3   4   4   6   6   3   3   3
## [2772]   3   4   4   3   3   5   4   5   5   6   4   4   5   4   4   4   4
## [2789]   4   5   5   5   4   5   5   3   3   3   4   3   5   4   4   4   3
## [2806]   3   7   3   3   4   6   3   4   4   4   3   6   5   3   8   7   4
## [2823]   3   4   3   4   4   3   4   3   3   5   4   3   6   3   5   5   5
## [2840]   4   3   5   5   5   4   3   3   3   3   3   3   5   4   3   5   3
## [2857]   3   3   3   3   3   4   3   5   3   4   4   6   4   4   3   3   3
## [2874]   5   4   3   6   4   4   4   4   3   4   4   5   4   4   3   4   3
## [2891]   7   4   3   4   4   5   5   4   3   3   3   3   3   5   3   3   4
## [2908]   5   4   3   3   4   5   6   3   3   4   7   3   3   3   5   3   5
## [2925]   3   3   3   3   4   3   3   6   6   3  12   5   4   3   4   3   3
## [2942]   4   4   3   4   6   3   3   3   6   6   4   3   4   4   3   3   3
## [2959]   5   5   4   3   3   3   4   6   5   3   3   3   4   5   4   9   5
## [2976]   3   4   7   4   6   4   3   3   6   6   5   3   3   3   4   4   4
## [2993]   4   3   6   5   4   4   4   3   3   4   5   4   4   3   4   5   3
## [3010]   3   4   3   3   4   4   3   3   3   3   5   5   3   5   4   3   4
## [3027]   4   4   4   3   3   6   3   4   5   4   3   4   4   4   4   3   5
## [3044]   4   7   5   3   6   4   4   5   3   3   4   3   4   3   3   4   3
## [3061]   3   3   4   3   3   4   3   4   3   6   3  10   5   6   3   4   5
## [3078]   4   4   4   5   4   4   3   4   3   4   5   4   3   6   4   3   4
## [3095]   5   3   3   4   4   6   6   6   5   4   3   3   4   4   4   4   4
## [3112]   3   3   5   3   3   5   4   3   3   4   3   5   3   3   3   3   3
## [3129]   4   8   3   4   4   4   6   4   6   6   4   5   4   8   3   5   3
## [3146]   3   3   3   5   3   3   4   4   4   5   8   3   4   4   6   4   7
## [3163]   4   5   5   5   3   3   4   3   4   5   4   3   3   3   6   3   3
## [3180]   5   4   3   4   4   3   4   3   3   4   3   5   5   3   4   3   4
## [3197]   5   3   3   3   3   5   6   3   3   5   4   3   3   3   6   4   5
## [3214]   3   3   3   3   3   4   4   5   3   4   4   4   5   5   3   4   5
## [3231]   5   5   5   4   3   4   4   4   4   4   3   3   3   3   6   4   6
## [3248]   3   6   3   6   4   3   3   4   3   4   3   3   3   4   5   3   7
## [3265]   3   3   3   4   3   3   4   3   3   4   4   3   3   4   5   3   3
## [3282]   4   4   4   3   3   3   5   3   5   3   7   3   4   3   3   3   4
## [3299]   3   4   4   8   3   3   3   4   3   3   3   3   3   3   5   3   3
## [3316]   4   3   5   3   3   3   3   4   3   3   4   4   3   3   3   3   3
## [3333]   3   3   5   4   4   4   5   4   4   3   6   3   5   4   3   3   3
## [3350]   3   7   3   3   3   3   4   3   3   4   3   6   3   3   5   3   5
## [3367]   3   3   4   3   4   4   3   3   3   4   3   3   4   4   3   3   4
## [3384]   4   4   4   3   3   4   4   3   7   3   4   6   3   4   4   5   3
## [3401]   3   4   4   4   5   3   5   3   4   3   4   5   3   3   3   3   3
## [3418]   3   6   4   3   4   3   3   3   4   3   3   3   3   4   5   3   3
## [3435]   4   4   5   3   7   3   4   3   3   3   3   3   6   4   5   6   4
## [3452]   3   3   4   3   4   3   3   4   4   6   3   4   4   4   5   4   4
## [3469]   3   3   6   3   4   4   3   4   3   4   3   5   3   5   4   4   4
## [3486]   3   4   3   3   4   3   5   5   5   4   6   3   5   3   3   5   3
## [3503]   3   3   3   4   3   4   3   5   4   3   4   4   3   3   3   3   4
## [3520]   4   3   4   3   4   6   4   3   4   3   4   3   4   6   4   3   4
## [3537]   4   3   3   5   3   4   3   3   6   3   3   4   3   3   3   3   4
## [3554]   3   5   6   3   3   3   3   3   3   4   5   4   3   4   3   3   4
## [3571]   3   4   4   3   3   4   3   3   3   3   5   4   3   4   4   4   3
## [3588]   4   3   4   4   3   4   3   3   3   3   5   6   3   4   5   3   3
## [3605]   3   6   5   4   5   4   3   4   3   5   3   3   3   3   5   4   4
## [3622]   4   3   3   4   3   4   3   5   4   3   4   3   4   3   3   3   3
## [3639]   4   7   4   3   3   3   4   5   5   3   3   3   3   4   5   5   3
## [3656]   3   3   4   3   4   5   3   3   3   3   4   3   5   3   3   3   4
## [3673]   4   3   3   3   5   4   3   4   3   3   4   3   3   3   3   3   3
## [3690]   6   3   3   3   4   4   3   3   4   3   3   3   3   3   3   3   3
## [3707]   4   3   3   4   4   3   3   4   4   4   3   3   4   3   4   3   3
## [3724]   3   3   5   3   3   3   3   3   3   3   3   4   3   6   3   3   3
## [3741]   3   3   3   5   3   5   3   4   4   3   3   3   4   3   3   3   3
## [3758]   3   3   3   4   4   3   4   4   3   3   3   3   4   3   3   4   3
## [3775]   4   3   5   3   3   4   3   3   4   3   3   4   3   3   3   3   3
## [3792]   5   3   3   6   3   3   4   3   4   3   3   3   4   3   3   4   3
## [3809]   3   3   3   3   3   3   3   3   3   3   3   4   4   5   5   3   3
## [3826]   3   3   3   3   5   3   3   3   3   4   5   3   3   3   3   3   3
## [3843]   5   4   4   5   3   5   4   3   3   6   4   3   4   3   3   3   4
## [3860]   5   3   3   3   3   3   3   5   3   3   4   3   3   3   4   3   3
## [3877]   4   3   3   3   5   3   3   4   3   3   4   4   3   5   4   3   7
## [3894]   5   4   3   4   3   3   4   3   3   4   3   3   3   3   3   3   3
## [3911]   5   3   5   7   3   4   3   4   4   3   4   4   4   3   5   3   3
## [3928]   3   5   3   3   3   3   3   6   4   3   3   3   4   3   3   3   3
## [3945]   3   3   3   3   3   3   4   3   3   3   3   3   4   4   4   3   3
## [3962]   3   3   4   3   3   3   4   3   4   3   3   3   5   4   3   4   3
## [3979]   4   3   3   3   3   3   3   3   4   4   7   3   3   4   3   3   3
## [3996]   4   3   3   3   3   3   4   3   3   3   3   3   3   3   3   4   3
## [4013]   3   4   3   3   3   3   3   5   3   4   4   3   3   3   3   4   3
## [4030]   3   3   5   3   4   4   4   3   3   4   3   4   3   3   3   3   3
## [4047]   3   3   3   3   4   3   4   3   4   3   3   4   3   3   3   3   3
## [4064]   3   4   5   3   3   3   3   3   3   3   3   3   4   3   3   3   3
## [4081]   3   3   3   3   4   3   3   3   3   5   4   4   3   3   3   3   3
## [4098]   3   3   3   3   4   3   3   3   3   4   3   4   3   3   3   4   3
## [4115]   3   3   3   5   4   3   4   3   3   4   3   3   3   4   6   3   3
## [4132]   3   4   4   3   3   4   3   3   3   3   5   3   3   3   3   3   3
## [4149]   4   3   3   4   4   3   4   3   3   3   3   3   3   3   5   3   3
## [4166]   3   3   3   3   4   3   3   3   3   3   3   3   3   3   4   3   4
## [4183]   3   4   4   4   3   4   3   4   3   3   4   6   3   3   3   3   3
## [4200]   3   4   5   3   3   3   3   3   3   4   3   4   3   3   4   4   3
## [4217]   3   4   4   3   3   3   3   3   3   3   4   3   3   3   3   4   3
## [4234]   3   3   4   3   4   3   3   3   3   3   3   3   3   4   3   3   4
## [4251]   3   4   3   4   3   3   3   3   3   3   4   3   3   3   3   4   4
## [4268]   3   3   3   5   4   3   3   3   3   4   3   4   3   3   3   3   3
## [4285]   3   3   3   4   3   3   3   3   3   4   3   3   4   3   3   3   3
## [4302]   3   3   3   3   5   4   3   5   3   5   4   3   4   3   3   4   5
## [4319]   3   4   3   4   4   3   3   3   3   3   4   3   3   3   4   3   3
## [4336]   4   3   4   3   3   3   3   4   3   3   3   3   3   3   4   3   4
## [4353]   3   4   3   3   3   3   4   3   3   3   3   3   3   3   4   3   3
## [4370]   3   3   3   5   4   4   3   4   3   4   4   4   3   3   3   3   3
## [4387]   3   3   3   3   4   3   3   3   3   3   3   4   3   3   3   3   3
## [4404]   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3   3   4
## [4421]   3   3   3   4   3   3   3   3   3   4   3   3   4   3   4   5   3
## [4438]   3   3   3   3   3   3   3   3   3   3   3   4   3   4   3   3   4
## [4455]   3   3   4   3   3   3   3   3   4   3   3   3   3   4   3   3   3
## [4472]   3   4   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4489]   3   6   4   3   3   3   3   3   3   3   3   3   3   3   3   4   3
## [4506]   3   3   3   3   3   3   3   3   3   4   3   4   3   4   3   3   3
## [4523]   3   3   3   3   3   3   3   3   3   3   3   4   4   3   3   3   3
## [4540]   3   3   3   3   3   3   3   3   3   3   3   5   3   3   4   3   3
## [4557]   3   3   3   4   3   4   3   3   3   3   3   3   3   3   4   3   3
## [4574]   3   3   3   3   3   3   3   3   3   3   3   3   3   4   3   3   3
## [4591]   3   3   3   3   3   3   4   3   3   3   3   4   3   3   3   3   3
## [4608]   3   3   4   3   3   3   3   3   3   3   3   3   3   3   3   3   4
## [4625]   3   3   4   3   3   4   3   3   3   3   3   3   3   3   3   3   3
## [4642]   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3   3   3
## [4659]   3   3   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3
## [4676]   3   3   3   4   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4693]   3   3   3   3   3   3   4   3   3   3   3   3   4   3   3   3   3
## [4710]   3   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3   3
## [4727]   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3   3   3
## [4744]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4761]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4778]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4795]   3   3   3   3   3   3   3   3   3   3   3   3   3   4   3   4   3
## [4812]   3   3   4   3   4   3   3   3   3   3   3   3   3   3   3   4   3
## [4829]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   4   3
## [4846]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   4   3   3
## [4863]   3   3   3   3   3   3   4   3   3   3   3   3   3   3   3   3   4
## [4880]   3   3   3   3   3   3   3   3   3   4   3   3   3   3   3   3   4
## [4897]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4914]   3   3   4   3   3   4   3   3   3   3   3   3   3   3   3   3   3
## [4931]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4948]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4965]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4982]   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3   3
## [4999]   3   3   3   3   3   3

Find and plot the degree distribution in i) linear scale

plot((degree.distribution(g5004,cumulative = FALSE,loops=FALSE,normalized=FALSE,mode=c("total"))),main = "Degree Distribution for 5004 Nodes",xlab = "Degrees",ylab = "Fractions")

and ii) log-log scale.

plot((degree.distribution(g5004,cumulative = FALSE,loops=FALSE,normalized=FALSE,mode=c("total"))),main = "Degree Distribution for 5004 Nodes Log/Log",xlab = "Degrees",ylab = "Fractions",log = "xy")

1(b): Repeat 1(a) but instead of always adding 3 links for each new node, add either 1, 2, or 3 links with equal probability. That is, the new node links to 1 node with probability 1/3, links to 2 nodes with probability 1/3, and to 3 nodes with probability 1/3. How many links does the final network have? Plot the degree distribution using i) linear scale and ii) log-log scale. 1(a): Create a network with 4 nodes that are connected to each other i.e., a complete graph with 4 nodes and the degree for all is 3.

n<-4
p.<-1
g<-erdos.renyi.game(n,p.,type = c("gnp"),directed = FALSE,loops = FALSE)
plot.igraph(g)

g
## IGRAPH 1bc296e U--- 4 6 -- Erdos renyi (gnp) graph
## + attr: name (g/c), type (g/c), loops (g/l), p (g/n)
## + edges from 1bc296e:
## [1] 1--2 1--3 1--4 2--3 2--4 3--4

Number of nodes is 4 Number of links is 6

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g,v=V(g), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 3 3 3 3

Adding a new node (the 5th one) to this existing network.

v<-c(0,.333,.333,.333)
g5<-barabasi.game(5, power = 1, m = NULL, out.dist = v, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g)
plot.igraph(g5)

g5
## IGRAPH 1bdd5be U--- 5 7 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/x), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 1bdd5be:
## [1] 1--2 1--3 1--4 2--3 2--4 3--4 2--5

Number of nodes is 5 Number of links is 7

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g5,v=V(g5), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 3 4 3 3 1

Add the 6th node in a similar fashion.

g6<-barabasi.game(6, power = 1, m = NULL, out.dist = v, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g5)
plot.igraph(g6)

g6
## IGRAPH 1bf75e2 U--- 6 10 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/x), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 1bf75e2:
##  [1] 1--2 1--3 1--4 2--3 2--4 3--4 2--5 3--6 2--6 5--6

Number of nodes is 6 Number of links is 8

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g6,v=V(g6), mode = c("total"),loops = FALSE, normalized = FALSE)
## [1] 3 5 4 3 2 3

Continue to add 5000 nodes.
In the following graph, larger Nodes have a higher degree and are shown in the center. You can also notice nodes with single links on the outskirts of the graph since we are adding a choice of links of 1,2, or 3 when a node enters.

g5004<-barabasi.game(5004, power = 1, m = NULL, out.dist = v, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g6)
deg <- degree(g5004, mode="all")
l <- layout_with_fr(g5004)
l <- norm_coords(l, ymin=-15.3, ymax=15.3, xmin=-23, xmax=23)
par(mfrow=c(1,1), mar=c(0,0,0,0))
plot(g5004, rescale=F, layout=l*.07,vertex.label=NA,vertex.size=deg*.1,edge.width=.0000000000000000001,edge.curved=.1)

g5004
## IGRAPH 1c109cb U--- 5004 10042 -- Barabasi graph
## + attr: name (g/c), power (g/n), m (g/x), zero.appeal (g/n),
## | algorithm (g/c)
## + edges from 1c109cb:
##  [1]  1-- 2  1-- 3  1-- 4  2-- 3  2-- 4  3-- 4  2-- 5  3-- 6  2-- 6  5-- 6
## [11]  5-- 7  4-- 7  1-- 8  5-- 8  4-- 9  7--10  1--10  4--11  7--12  2--13
## [21]  5--13  7--14  3--14  2--15  3--16  2--16 10--16 12--17  8--18 11--18
## [31]  5--19  2--19 11--19  5--20  2--20  3--20 20--21  3--21 14--21  6--22
## [41] 15--22  3--23 21--23  6--24 23--25 20--25  1--26  2--26  2--27 20--28
## [51] 16--28  4--29  5--29 21--29  2--30 21--30 10--30 12--31  3--31  5--31
## [61]  5--32  3--33 32--33 26--34 13--34 31--34 10--35  2--35 12--35  3--36
## + ... omitted several edges

Number of nodes is 5004 Number of links is 9993

Degree for each node in order(Node 1 ..2..3…4..n) below:

degree(g5004,v=V(g5004), mode = c("total"),loops = FALSE, normalized = FALSE)
##    [1]  29 108  71  72  75  52  29   7   7  41  34  31  20  14   4  18   8
##   [18]  35  31  53  50  21  27  47  18  16  22  32  41  28  32  30  42   7
##   [35]  25  36  21  19  12  39   2  29  16  24   4  22  20  20  28  22  17
##   [52]  13  31  11  14   5  35  27   6  20   7  16   6  35   6  14  10   2
##   [69]  22  14  10  11   5  30  33   9  22  30  16  45  10  10  20   9  36
##   [86]  21   9  23  17   6  13   5   4  31  25   6   4  12   6   9  14  22
##  [103]  32  26   8  18  17  11  15   7   3   9  26  13  17  10  10   6   2
##  [120]  14  14  21  10  13   6   3   8   1   9  13   8   9   7   3   7   7
##  [137]   5   6  16   9  12  13  18  10  16  28  10   2   6  17  16   7   6
##  [154]   9  19   5   7  11   7   7  13   7   9   8   5  11   9   5  13   4
##  [171]   4   2  13  12   4  15  17  45  19  10  10  11   8   6  23   4   4
##  [188]  13  12  11   7  19  11  17   4   3   6   9  18  18  19  21  10   5
##  [205]  13   8  11  11   4   8   2   7   4   5   4   7   7  16  10  14  11
##  [222]   6   3   8  11   6   7   1   6  15   6   9  10  12  21  12   9   8
##  [239]   9  17   8   2  10  12  10   6  13   7   6  13  13   9  17   6   2
##  [256]  11  19  10   5   8  11   8   6  15  16   5  13  15   8   8   7  18
##  [273]  10  12  10   5  10   1   8  14   9  10   6  11   6   4  13  13  13
##  [290]   9   9  13  16   1   7   3  14   9   9   9   8  12   8   5   6   3
##  [307]   3  11   4   3   1   1   6   7  17   5   6   5   5  15   2   2  14
##  [324]   9   4   6   7  10  11   2   4   9   8   6   6  10   4  14   5   2
##  [341]   5   4  17   4  21   6   9   8   4   6  22   4   6  11  12  18  15
##  [358]   7   2   8  22   8   8   6   2  11  16   5  15   5  11   3   3  11
##  [375]   3   4   5  11   2   2   5   8   3   4   6  11   5   5   8  14   1
##  [392]   5   5  10   8   4  10  14  11   4  14   2   4   4   4   5  15  11
##  [409]  13  14  11   3   8   4   2  10   7   2   1  11   3  11  10  10   7
##  [426]  13   6   3   2   9   4   3  11   6  15   4   9   8   6  12  10   7
##  [443]  12  12   6   6   9  10   7   6   6   1   9   3   3   2   5   4   9
##  [460]  11   2   1   9   3   7  16   2   3   2  11   4  10   9   9   6   6
##  [477]   8   6   9   5   2   2   7   5   3   2  14  17   4   2   5   1   8
##  [494]  11  14   9   5   7   2   1   7   8   7  22   5   2   2   5   9   5
##  [511]   7  17   2   9   2   8   4   9   1   3   1   6   4   5   9   6   6
##  [528]   8   9  10  21  10   7   2   4  14   6   4   4  11   8   9  12   3
##  [545]   3   2   5   6  10   9   5   5   6   3   8   2   9   4   3   5  10
##  [562]   3   8  10   1   7   8   4   6   3   3   6   1   4   6   6   8   5
##  [579]   1   2   4  12   9   1  11   5   2   9   3  15   4   1   2   3   7
##  [596]  10   2   5   7   5   8   5   5   5   1   6   9   7   4   5   5   3
##  [613]   6   1   3   9   6   2   2   6  10   4   8   7   8   4  10   7  12
##  [630]   8  10   6   3   5   2  13  13  10   8   4   7   2   5   7   5   4
##  [647]   3   5   6   5   1   7  10   8   3  13   1  19   6   3   8   3  13
##  [664]   5   4   6   4   1   9  10   3   5  11   6   5   2   7   3   3   9
##  [681]   6   6   8  16   2   8   8  10   6   3   7   1   8   9   7  21   7
##  [698]   4   8   4   2   5   1   5   8   8   2   9   2   8   2   5   1   9
##  [715]   3   4   5   6   6   2   3   6   5   6  11   4   2   8   8   2   6
##  [732]   9   4   1   2   8   6  11  10   2   7   4   2   4   6   3   8   4
##  [749]   6   2   8  11   4   4   3   6   7   8   1  12   7   2   3   2   2
##  [766]   8   1   4   4   6   6   2   6   6   5   2   6   5   2   7   7   6
##  [783]   3  10   6   7   4   3   3   6   4  10  11   4   1  10   8   7   8
##  [800]   6   2   4   2  12   1   4   9   2   5   3   6   9   4   3   6   4
##  [817]   1   7   1   6   2   7  14   7   7   7   2   7   5   3   6   3  10
##  [834]   3   4   3   8   4  10   3   5   4   4   3  12   2   2   4   7   5
##  [851]   6   5   3   1   5   7   7  11   3  13   4   8   7   4   5   4   4
##  [868]   6   8   3   2   2   6   2  11   4   5   2   2   4   1   4   6   6
##  [885]   5   1   8   7   5   3   6   5   3  12   2   5   3   3   2   7   7
##  [902]   1   3  12   8   2   4   1   8   5  12   4   7   5  12   1   8   6
##  [919]   4   3   2   5   1   1   3  10   7   1   9   4   5   3   5   6   5
##  [936]   5   3   3   6   6   8   9   3   1   9   5   3   2   5   3   4   2
##  [953]   1   4   9   5   2  11   2   9   4   9   3   9   3   2   5   3   8
##  [970]   7   5   6   2   9   1   1   5   7   1   5  10   3   2   3   9  19
##  [987]   1   4   2   8   1   3   1   4   8   6   8   3   4   6   4   4   5
## [1004]   4   2   6   3   5   2   5   3   4   1   2   3   3   3   6   5   2
## [1021]   4   5   2   5   4   8   2   7   1   3   5   5   2   5   6   2   2
## [1038]   2   1   1   5   5   2   5   5  10   2   4   3   4   4   3   4   3
## [1055]   2   1   2   5   8   4   2   8   8   4   3   1   2   2   5   4   2
## [1072]   3   2   3   2   3   3   3   9   3   6   6   1   4   4   4  11   1
## [1089]   8   6   9   3   3   4   6   2   4   7   3   7   2   5   1   3   3
## [1106]   4   1   2   9   3   7   3   8   4   7   3   3   8  10   4   1   2
## [1123]   3   4  12   4   2   5   4   4   5   4   3   5   5   4   8   3   9
## [1140]   4   3  12   3   6   6   2   3   6   7   4   4   4   5   1   3   2
## [1157]   1   1   1   3   3   8   3   5  10   3   1  10   5   4   2   4   8
## [1174]  12   1   4   3   3   1   5   6   5   5   5   7   4   1   4   7   2
## [1191]   3   4   5   5   3   4   2   3   2   4   4   8   8   4   5   4   6
## [1208]   1   8   7   2   4   3   2   3  13   7   3   6   5   4   4   4   1
## [1225]   2  11   3   2   3   1   4   1   5   6  10   7   4   6   4   4   1
## [1242]   3   1  10   7   3   3   6   4   5   2   8   5   1   5   2   8   7
## [1259]   4   1   3   3   6   6   5   2   8   4   6   2   2   2   1   3   1
## [1276]   7   8   3   5   5   5   3   2   3   2   2   4   4   6   4   5   3
## [1293]   3   2   9   5   1   4   1   4  11   5  11   1   6   2   3   7   8
## [1310]   1   1   7   3   8   1   6   9   5   1   3  11   2   4   6   5   4
## [1327]   6   3   3   1   3   2   4   8   1   3   9   2   2   3   2   1   6
## [1344]   4   4   4   2   5   3   4   5   6   4   2   3   2   8   5   5   3
## [1361]   8   1   4   7   3   2   2   4   8   3   2   4   6   4   2   4   1
## [1378]   3   5   5   4   2   2   2   7   2   4   2   4   2   5   3   3   5
## [1395]   2   3   6   3   6   2   1   2   6   5   1   2   3   3   6   7   4
## [1412]   6   4   4   6   7  10   2   1   2   2   1   3   3   5   2   7   7
## [1429]   2   5   3   3  12   1   6   1   2   5   7  10   4   2   5   2   3
## [1446]   3  10   5   5   1   2   3   3   2   2   1   2   1   2   5   3   4
## [1463]   4   2   2   2   5   1   2   2   2   2   3   2   2   1   5   3   2
## [1480]   1   6   5   3   2   2   1   6   5   1   2   3   2   3   1   5   6
## [1497]   5   1   1   4  12   4   3   3   8   5   2   6   4   9   5   4   5
## [1514]   1   7   2   2   4   3   4   3   2   3   1   2   3   1   3   3   2
## [1531]   3   5   1   7   4   3   7   4   2   1   1   4   5   3   5   2   4
## [1548]   1   6   5   4   4   2   4   3   1   1   4   1   1   6   8   5   5
## [1565]   1   4   6   4   3   6   7   4   5   2  10   1   4   6   4   3   4
## [1582]   5   6   5   3   3   1   9   6   3   2   1   8   2   4   5   3   8
## [1599]   5   4   1   3   6   4   6   3   3   3   2   3   5   4   3   1   3
## [1616]   2   1   5   1   6   4   7  10   3   5   7   3   3   2   8   2   6
## [1633]   3   6   2   3   4   4   5   3   4   5   2   3   2   6   3   1   3
## [1650]   5   5  11   5   2   2   1   4   2   6   3   4   3   1   4   4   3
## [1667]   3   4   2   2   3   1   1   2   4   2   3   4   3   4   4   3   3
## [1684]   1   3   8   5   4   6   4   4   4   3   5   2   2   1   8   4   5
## [1701]   4   5   3   3   7   4   1   1   2   7   5   2   2   3   8   1   2
## [1718]   8   4   7   4   3  11   1   2   5   3   4   4   4   2   3   6   4
## [1735]   1   4   4   4   3   4   5   4   2   3   5   2   4   6   4   1   7
## [1752]   4   2   7   6   1   1   6   3   4   4   6   4   4   2   1   6   3
## [1769]   4   6   4   3   8   5   4   1   5   2   2   6   1   1   1   5   1
## [1786]   5   1   3   4   4   1   3   5   3   8   5   3   4   1   2   5   6
## [1803]   2   4   8   3   2   3   3   1   1   2   4   3   4   1  10   3   4
## [1820]   4   2   6   7   3   1   6   3   4   2   3   5   3   4   1   4   2
## [1837]   7   5   3   1   5   6   2   4   4   5   2   2   9   6   5   3   5
## [1854]   3   5   1   2   3   1   1   3   4   2   5   7   4   2   1   4   2
## [1871]   3   3   2   3   4   1   3   5   3   6   5   1   4   5   3   3   3
## [1888]   5   3   4   3   4   3   3   2   5   7   3   3   2   3   2   2   5
## [1905]   3   5   5   3   1   5   3   6   3   5   3   6   4   3   2   1   3
## [1922]   2   2   3   6   5   4   2   8   2   5   1   4   3   3   6   6   2
## [1939]   2   4   2   5   4   7   3   2   2   5   1   5   1   5   3   3   5
## [1956]   5   3   3   4   4   1   3   3   1   1   3   3   4  10   3   3   4
## [1973]   1   2   1   2   3   2   1   1   6   3   2   6   4   5   3   3   6
## [1990]   4   6   2   3   2   8   1   1   2   1   4   1   1   5   7   2   2
## [2007]   6   3   4   1   1   2   4   1   4   6   4   3   2   5   2   4   4
## [2024]   5   3   3   2   5   3   2   4   3   2   3   7   4   1   4   4   3
## [2041]   6   2   4   2   4   2   3   4   2   2   2   1   4   2   4   2  10
## [2058]   2   2   3   3   6   5   1   2   5   6   7   4   4   1   3   1   4
## [2075]   6   2   4   1   2   4   4   1   4   3   2   3   3   4   3   2   3
## [2092]   2   3   5   3   3   1   4   3   3   6   2   1   2   2   2   3  12
## [2109]   3   4   2   1   2   1   3   2   3   4   7   1   4   3   2   3   5
## [2126]   4   2   3   4   4   1   3   1   3   1   5   3   2   4   6   2   2
## [2143]   2   9   1   2   6   1   1   2   3   4   5   2   3   1   2   2   3
## [2160]   2   2   2   4   5   5   3   3   1   4   3   2   1   4   5   2   4
## [2177]   4   4   4   7   1   1   5   3   2   8   2   5   5   3   2   4   1
## [2194]   1   3   4   5   5   1   2   1   1   3   6   2   3   2   3   1   1
## [2211]   4   2   1   2   4   1   5   3   6   1   3   1   1   3   3   4   2
## [2228]   3   3   5   3   4   3   4   4   3   2   1   2   1   6   2   4   2
## [2245]   4   2   1   4   4   5   1   5   3   2   3   2   5   3   4   7   4
## [2262]   4   3   3   2   2   5   4   3   3   3   2   5   2   3   2   1   4
## [2279]   3   7   6   5   1   2   4   5   3   4   2   2   8   3   1   6   6
## [2296]   3   7   2   2   1   3   4   2   2   3   5   4   4   2   4   3   2
## [2313]   2   7   1   3   5   3   2   4   2   2   1   1   2   1   4   3   1
## [2330]   2   4   1   3   2   3   3   6   5   6   3   1   3   7   3   1   2
## [2347]   4   6   4   5   2   1   1   2   4   2   3   5   4   3   2   2   4
## [2364]   3   2   4   1   3   2   7   4   4   3   1   2   5   1   2   1   3
## [2381]   1   2   2   4   2   1   2   2   4   3   3   2   4   3   3   5   2
## [2398]   1   1   2   4   3   5   3   1   3   5   3   4   6   2   4   4   2
## [2415]   3   1   1   3   7   1   3   2   3   4   1   4   4   3   2   2   3
## [2432]   3   2   2   2   3   4   1   3   5   2   2   2   3   5   2   5   5
## [2449]   3   3   3   3   1   4   2   1   2   1   4   4   3   4   2   2   2
## [2466]   2   4   3   5   1   5   3   5   3   1   3   2   2   8   1   1   3
## [2483]   2   2   4   6   2   3   4   4   3   3   1   4   3   5   5   3   2
## [2500]   4   3   2   3   3   2   1   3   6   2   4   2   4   3   5   3   4
## [2517]   3   3   4   2   9   3   2   2   3   2   5   2   3   2   5   4   4
## [2534]   1   2   3   2   1   3   1   1   1   4   2   1   2   5   5   2   4
## [2551]   2   6   4   2   4   2   3   2   4   4   3   6   4   3   2   1   3
## [2568]   3   1   2   4   4   3   2   2   5   4   2   7   3   6   4   1   6
## [2585]   2   7   2   3   2   4   2   2   2   5   4   8   1   1   2   5   4
## [2602]   2   1   1   1   5  10   3   1   3   3   3   4   1   4   3   3   4
## [2619]   5   1   3   2   1   3   4   2   3   4   4   4   3   2   6   2   2
## [2636]   2   3   3   2   5   4   3   3   3   3   6   1   3   2   4   4   4
## [2653]   3   1   5   3   1   5   3   2   4   6   4   4   3   1   3   2   4
## [2670]   4   5   3   3   2   3   2   3   4   5   1   3   1   4   3   3   4
## [2687]   5   2   5   1   4   3   4   2   5   1   2   4   3   4   3   2   4
## [2704]   8   2   4   1   3   4   2   4   4   4   4   1   1   4   5   6   4
## [2721]   3   2   3   2   2   4   3   5   3   4   1   1   2   2   3   1   1
## [2738]   7   2   1   1   2   4   3   1   3   2   4   1   2   1   3   3   1
## [2755]   1   2   2   4   7   7   2   2   2   5   3   3   1   2   4   4   2
## [2772]   8   5   3   4   3   5   3   6   4   3   2   1   1   3   4   1   1
## [2789]   4   2   3   4   3   1   3   2   1   3   1   2   4   1   2   4   2
## [2806]   1   3   2   1   4   2   6   3   1   1   1   1   4   3   4   1   3
## [2823]   3   3   3   2   3   3   2   5   3   5   1   1   2   1   3   4   4
## [2840]   2   1   2   3   2   2   2   1   1   1   3   4   2   4   4   2   2
## [2857]   2   3   4   4   1   4   4   1   1   3   3   1   4   2   5   3   1
## [2874]   3   1   2   1   3   1   4   2   2   2   4   5   3   3   2   4   1
## [2891]   4   9   1   2   6   2   2   3   1   8   2   2   4   2   3   1   4
## [2908]   2   6   4   1   4   3   4   2   3   3   2   2   1   2   1   4   5
## [2925]   3   2   2   5   2   1   1   5   4   3   1   2   1   2   5   3   2
## [2942]   2   5   5   1   3   2   4   3   2   2   4   2   6   4   3   1   2
## [2959]   1   5   2   5   4   1   5   1   5   3   3   3   3   1   3   1   3
## [2976]   3   2   2   1   1   3   3   2   2   3   6   3   6   1   4   4   4
## [2993]   2   2   5   2   2   3   6   1   2   5   3   2   3   1   2   2   1
## [3010]   4   4   3   1   5   2   4   4   2   2   3   1   1   2   3   3   4
## [3027]   2   3   1   2   2   2   2   2   3   1   4   6   2   1   5   1   1
## [3044]   1   2   4   4   1   3   4   4   3   1   4   5   1   4   3   1   1
## [3061]   3   4   1   5   3   4   3   1   2   1   1   3   2   4   2   3   2
## [3078]   2   3   3   3   5   4   3   5   2   1   1   1   2   4   3   1   2
## [3095]   2   5   3   3   2   2   1   2   1   1   3   2   3   1   3   4   4
## [3112]   2   3   1   2   4   3   1   4   1   3   3   5   3   2   6   1   3
## [3129]   3   3   3   1   3   3   2   5   1   1   3   1   1   2   2   1   1
## [3146]   5   5   1   1   2   7   2   3   1   3   2   2   2   3   3   2   3
## [3163]   3   3   1   4   1   1   2   3   1   4   3   3   4   3   2   3   1
## [3180]   6   1   3   2   1   2   3   4   1   2   3   4   1   2   2   3   3
## [3197]   4   3   2   1   2   4   1   1   3   4   2   3   2   3   4   4   4
## [3214]   2   1   4   2   3   1   2   3   3   4   5   1   2   3   2   3   2
## [3231]   4   2   3   2   3   3   2   1   3   3   3   2   3   4   1   2   3
## [3248]   3   3   3   1   3   1   4   3   3   2   3   1   5   2   1   2   2
## [3265]   4   6   1   1   4   2   6   5   3   3   3   2   3   1   4   1   1
## [3282]   2   3   2   3   1   3   3   2   1   3   1   3   4   2   5   2   3
## [3299]   2   3   2   3   4   1   1   4   3   5   1   3   3   4   1   3   4
## [3316]   2   1   1   3   1   7   1   2   4   1   2   2   1   1   3   4   4
## [3333]   2   3   1   3   2   1   3   1   2   1   1   1   4   3   3   1   2
## [3350]   1   4   3   2   2   3   3   2   4   4   2   5   3   1   1   2   1
## [3367]   3   3   3   1   2   3   4   6   3   4   2   1   1   1   2   5   1
## [3384]   2   5   3   2   3   3   1   1   5   3   2   4   3   1   3   2   2
## [3401]   2   2   3   2   4   1   2   4   3   3   7   2   1   2   3   2   2
## [3418]   3   3   2   1   2   4   2   3   4   2   3   2   1   1   2   2   4
## [3435]   2   4   1   1   2   3   2   6   2   3   1   3   4   3   4   1   3
## [3452]   3   3   4   2   5   3   2   4   3   2   1   2   2   2   3   1   3
## [3469]   5   3   1   2   1   2   1   1   1   2   3   3   5   1   3   1   2
## [3486]   3   3   3   1   4   1   2   3   1   2   2   3   5   2   2   1   3
## [3503]   5   2   1   3   2   1   1   1   2   3   1   3   2   3   1   3   3
## [3520]   1   2   4   3   1   4   2   2   2   3   2   1   4   2   4   1   2
## [3537]   2   5   1   2   3   1   4   3   2   1   4   2   3   2   1   3   3
## [3554]   3   1   3   2   3   2   4   3   1   4   2   1   2   3   4   3   2
## [3571]   1   5   1   2   3   1   2   2   3   2   2   1   1   3   1   2   3
## [3588]   3   1   3   4   3   2   1   1   3   3   2   3   3   7   3   5   1
## [3605]   1   4   1   3   1   2   3   2   2   4   5   3   2   2   1   3   5
## [3622]   3   3   3   4   3   1   1   4   3   1   3   1   1   2   3   3   4
## [3639]   3   3   1   1   2   1   2   1   4   2   3   3   3   2   3   1   4
## [3656]   4   2   2   3   3   4   3   3   2   3   3   1   1   4   2   1   3
## [3673]   1   1   2   3   3   3   1   3   2   2   3   2   3   3   4   3   4
## [3690]   1   2   2   2   2   2   3   2   1   1   4   1   3   3   2   2   1
## [3707]   3   1   3   3   3   1   4   3   2   3   1   3   3   2   3   4   3
## [3724]   3   3   2   2   3   2   2   3   3   3   2   2   1   3   3   1   2
## [3741]   3   3   1   3   2   2   1   4   5   3   1   4   2   3   3   1   4
## [3758]   2   1   3   4   3   2   1   2   2   1   1   1   2   3   3   4   1
## [3775]   2   3   3   3   1   2   2   3   2   2   2   2   1   2   3   4   4
## [3792]   4   2   2   3   3   1   1   3   4   2   2   2   4   1   3   2   1
## [3809]   1   1   2   1   1   2   2   1   4   3   2   1   2   3   4   3   1
## [3826]   2   1   4   3   1   3   2   1   4   2   2   1   1   3   3   1   1
## [3843]   4   3   2   1   2   2   2   3   1   2   3   4   1   3   3   2   3
## [3860]   3   2   3   3   4   2   1   1   1   4   2   2   2   2   3   3   1
## [3877]   1   2   2   2   2   2   2   1   2   3   2   1   4   1   1   1   2
## [3894]   3   3   3   2   2   1   3   3   1   1   1   4   2   4   4   1   3
## [3911]   2   3   1   3   1   3   5   4   3   2   2   1   5   3   1   3   2
## [3928]   2   3   3   4   2   3   1   2   1   2   1   4   3   3   1   3   4
## [3945]   2   2   1   2   3   4   3   2   2   3   2   4   3   5   3   2   1
## [3962]   2   2   3   3   1   3   1   2   1   3   3   3   2   1   2   1   4
## [3979]   1   1   2   1   3   1   1   3   2   4   2   3   3   3   1   1   1
## [3996]   3   3   5   2   2   2   1   4   3   2   1   2   3   2   2   2   6
## [4013]   1   1   3   1   3   2   3   1   3   3   1   3   3   1   4   2   1
## [4030]   2   5   3   4   1   2   2   1   4   2   2   3   1   4   4   3   1
## [4047]   1   3   2   4   1   4   3   2   3   3   1   3   1   2   1   2   1
## [4064]   3   5   1   2   4   3   2   1   2   2   3   2   2   3   1   3   2
## [4081]   4   3   3   1   3   3   1   3   1   3   3   3   3   3   5   1   3
## [4098]   3   1   2   1   3   3   1   5   2   1   1   3   3   2   3   6   2
## [4115]   1   3   2   2   1   3   1   4   4   3   4   2   1   2   2   4   1
## [4132]   4   2   4   3   3   2   3   3   2   3   1   2   1   3   3   3   1
## [4149]   3   3   2   2   1   1   1   2   2   3   2   2   4   2   3   1   1
## [4166]   2   1   2   3   3   3   3   2   3   3   2   3   1   2   4   1   2
## [4183]   3   3   2   4   1   2   4   2   3   3   2   1   3   3   2   3   1
## [4200]   4   3   4   3   1   1   4   5   3   4   2   1   4   2   3   1   3
## [4217]   2   3   3   2   2   2   4   1   2   2   3   3   2   3   2   1   2
## [4234]   3   3   2   3   1   2   4   3   1   2   1   4   2   3   1   3   1
## [4251]   3   1   3   3   3   1   2   3   2   1   2   2   3   3   1   4   2
## [4268]   2   1   1   2   2   2   2   2   1   1   3   1   1   2   3   2   3
## [4285]   2   3   1   3   3   2   3   1   2   5   2   2   1   3   1   3   1
## [4302]   2   2   2   1   3   1   4   1   2   3   1   3   2   4   3   2   2
## [4319]   3   1   1   2   4   3   1   3   3   2   2   3   3   1   3   3   3
## [4336]   1   1   1   3   2   1   1   1   2   1   2   3   2   1   1   4   1
## [4353]   2   3   1   3   1   2   3   2   1   1   2   2   4   2   3   3   2
## [4370]   3   1   2   4   1   1   1   1   1   3   2   4   1   3   1   2   2
## [4387]   1   1   3   1   3   1   1   2   3   2   2   2   1   3   1   3   3
## [4404]   5   2   3   1   4   4   1   2   1   3   4   1   3   2   2   3   1
## [4421]   1   3   2   3   3   1   1   2   1   2   1   1   1   2   1   1   2
## [4438]   1   3   2   4   3   6   2   2   1   1   2   2   1   3   3   1   1
## [4455]   1   2   2   2   4   3   2   4   3   2   2   2   2   2   3   4   1
## [4472]   2   2   2   3   2   3   3   1   1   2   3   1   1   3   4   1   2
## [4489]   2   3   3   2   3   1   4   2   3   3   3   3   2   1   3   1   1
## [4506]   3   1   3   3   3   3   2   3   3   1   1   3   2   3   4   3   3
## [4523]   3   2   2   2   1   1   2   3   2   2   3   2   2   2   2   4   1
## [4540]   4   3   2   3   4   1   3   3   4   1   3   1   3   2   2   2   1
## [4557]   1   1   1   3   4   2   2   1   1   2   2   4   1   1   4   3   2
## [4574]   2   3   2   2   1   4   2   3   1   1   2   3   3   1   3   3   1
## [4591]   1   3   1   2   2   1   3   4   1   4   2   1   2   3   2   3   3
## [4608]   3   4   2   2   3   3   3   3   3   1   1   2   2   2   3   2   1
## [4625]   2   2   2   2   1   3   3   2   1   3   2   3   2   2   1   3   2
## [4642]   3   3   3   2   3   3   3   3   3   3   1   2   2   3   2   3   2
## [4659]   1   2   3   3   3   1   3   2   2   2   2   2   3   1   5   2   3
## [4676]   1   1   2   3   3   1   1   3   3   3   2   3   2   3   2   2   1
## [4693]   3   2   3   1   2   1   2   3   2   2   1   3   3   1   3   1   2
## [4710]   3   1   1   2   1   3   3   2   2   2   3   3   2   1   2   3   3
## [4727]   2   1   1   2   3   1   2   1   3   1   3   2   1   4   3   1   2
## [4744]   3   1   2   3   1   2   3   4   1   2   2   2   2   2   2   3   2
## [4761]   1   3   2   3   2   3   1   1   1   3   3   1   3   3   2   3   1
## [4778]   3   2   1   1   1   4   3   2   3   1   1   3   2   2   2   3   4
## [4795]   1   1   1   3   1   3   1   3   2   3   1   2   3   4   3   1   1
## [4812]   2   2   1   1   3   2   2   2   2   1   1   3   3   1   3   3   2
## [4829]   2   2   3   2   3   3   3   2   1   2   1   3   1   3   2   1   3
## [4846]   1   3   1   2   2   2   3   2   3   2   1   3   3   1   1   3   1
## [4863]   3   1   1   3   3   1   3   1   2   3   1   2   3   2   3   1   2
## [4880]   3   2   3   1   1   2   1   2   3   2   1   2   1   1   1   1   2
## [4897]   1   2   1   1   3   3   1   3   1   1   2   3   2   1   3   1   3
## [4914]   1   2   1   2   2   2   1   2   1   2   1   2   1   2   1   3   2
## [4931]   3   3   2   1   1   1   3   3   3   3   3   3   3   2   2   1   1
## [4948]   2   3   1   3   2   3   1   3   2   1   2   3   2   3   3   3   2
## [4965]   2   2   3   1   3   3   1   3   1   3   2   1   1   2   2   1   2
## [4982]   3   1   1   3   1   1   2   3   2   1   2   3   3   3   3   1   1
## [4999]   2   1   3   1   3   2

Find and plot the degree distribution in i) linear scale

plot((degree.distribution(g5004,cumulative = FALSE,loops=FALSE,normalized=FALSE,mode=c("total"))),main = "Degree Distribution for 5004 Nodes",xlab = "Degrees",ylab = "Fractions")

and ii) log-log scale.

plot((degree.distribution(g5004,cumulative = FALSE,loops=FALSE,normalized=FALSE,mode=c("total"))),main = "Degree Distribution for 5004 Nodes Log/Log",xlab = "Degrees",ylab = "Fractions",log = "xy")

  1. (4 points) Find the degree distribution of the Barabasi-Albert model analytically. That is, each time a new node arrives and connects with m nodes proportional to the existing nodes’ degree (which is nothing but the preferential attachment model). Hint: Refer to the book.

EXtra Credit Assignment Part 2 (The 2, 5004 node newtworks are already plotted in their corresponding sections) Following are the 2 network plots for 100 additional nodes. 3 Fixed links when arriving into network: In the following graph, larger Nodes have a higher degree and are shown in the center.

g5004<-barabasi.game(104, power = 1, m = 3, out.dist = NULL, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g)
deg <- degree(g5004, mode="all")
l <- layout_with_fr(g5004)
l <- norm_coords(l, ymin=-15.3, ymax=15.3, xmin=-23, xmax=23)
par(mfrow=c(1,1), mar=c(0,0,0,0))
plot(g5004, rescale=F, layout=l*.07,vertex.label=NA,vertex.size=deg*.1,edge.width=.0000000000000000001,edge.curved=.1)

Choice of 1,2, or 3 links: In the following graph, larger Nodes have a higher degree and are shown in the center. You can also notice nodes with single links on the outskirts of the graph since we are adding a choice of links of 1,2, or 3 when a node enters.

g5004<-barabasi.game(104, power = 1, m = NULL, out.dist = v, out.seq = NULL,
  out.pref = FALSE, zero.appeal = 1, directed = FALSE,
  algorithm = c("psumtree"), start.graph = g)
deg <- degree(g5004, mode="all")
l <- layout_with_fr(g5004)
l <- norm_coords(l, ymin=-15.3, ymax=15.3, xmin=-23, xmax=23)
par(mfrow=c(1,1), mar=c(0,0,0,0))
plot(g5004, rescale=F, layout=l*.07,vertex.label=NA,vertex.size=deg*.1,edge.width=.0000000000000000001,edge.curved=.1)