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data(murders)
class(murders)
## [1] "data.frame"

#for structure:

str(murders)
## 'data.frame':    51 obs. of  5 variables:
##  $ state     : chr  "Alabama" "Alaska" "Arizona" "Arkansas" ...
##  $ abb       : chr  "AL" "AK" "AZ" "AR" ...
##  $ region    : Factor w/ 4 levels "Northeast","South",..: 2 4 4 2 4 4 1 2 2 2 ...
##  $ population: num  4779736 710231 6392017 2915918 37253956 ...
##  $ total     : num  135 19 232 93 1257 ...

#for viewing 51 rows in murder dataset:

head(murders)
##        state abb region population total
## 1    Alabama  AL  South    4779736   135
## 2     Alaska  AK   West     710231    19
## 3    Arizona  AZ   West    6392017   232
## 4   Arkansas  AR  South    2915918    93
## 5 California  CA   West   37253956  1257
## 6   Colorado  CO   West    5029196    65

#for viewing 51 rows in murder dataset:

head(murders)
##        state abb region population total
## 1    Alabama  AL  South    4779736   135
## 2     Alaska  AK   West     710231    19
## 3    Arizona  AZ   West    6392017   232
## 4   Arkansas  AR  South    2915918    93
## 5 California  CA   West   37253956  1257
## 6   Colorado  CO   West    5029196    65
head(murders,51)
##                   state abb        region population total
## 1               Alabama  AL         South    4779736   135
## 2                Alaska  AK          West     710231    19
## 3               Arizona  AZ          West    6392017   232
## 4              Arkansas  AR         South    2915918    93
## 5            California  CA          West   37253956  1257
## 6              Colorado  CO          West    5029196    65
## 7           Connecticut  CT     Northeast    3574097    97
## 8              Delaware  DE         South     897934    38
## 9  District of Columbia  DC         South     601723    99
## 10              Florida  FL         South   19687653   669
## 11              Georgia  GA         South    9920000   376
## 12               Hawaii  HI          West    1360301     7
## 13                Idaho  ID          West    1567582    12
## 14             Illinois  IL North Central   12830632   364
## 15              Indiana  IN North Central    6483802   142
## 16                 Iowa  IA North Central    3046355    21
## 17               Kansas  KS North Central    2853118    63
## 18             Kentucky  KY         South    4339367   116
## 19            Louisiana  LA         South    4533372   351
## 20                Maine  ME     Northeast    1328361    11
## 21             Maryland  MD         South    5773552   293
## 22        Massachusetts  MA     Northeast    6547629   118
## 23             Michigan  MI North Central    9883640   413
## 24            Minnesota  MN North Central    5303925    53
## 25          Mississippi  MS         South    2967297   120
## 26             Missouri  MO North Central    5988927   321
## 27              Montana  MT          West     989415    12
## 28             Nebraska  NE North Central    1826341    32
## 29               Nevada  NV          West    2700551    84
## 30        New Hampshire  NH     Northeast    1316470     5
## 31           New Jersey  NJ     Northeast    8791894   246
## 32           New Mexico  NM          West    2059179    67
## 33             New York  NY     Northeast   19378102   517
## 34       North Carolina  NC         South    9535483   286
## 35         North Dakota  ND North Central     672591     4
## 36                 Ohio  OH North Central   11536504   310
## 37             Oklahoma  OK         South    3751351   111
## 38               Oregon  OR          West    3831074    36
## 39         Pennsylvania  PA     Northeast   12702379   457
## 40         Rhode Island  RI     Northeast    1052567    16
## 41       South Carolina  SC         South    4625364   207
## 42         South Dakota  SD North Central     814180     8
## 43            Tennessee  TN         South    6346105   219
## 44                Texas  TX         South   25145561   805
## 45                 Utah  UT          West    2763885    22
## 46              Vermont  VT     Northeast     625741     2
## 47             Virginia  VA         South    8001024   250
## 48           Washington  WA          West    6724540    93
## 49        West Virginia  WV         South    1852994    27
## 50            Wisconsin  WI North Central    5686986    97
## 51              Wyoming  WY          West     563626     5

#for viewing the last murder dataset:

tail(murders)
##            state abb        region population total
## 46       Vermont  VT     Northeast     625741     2
## 47      Virginia  VA         South    8001024   250
## 48    Washington  WA          West    6724540    93
## 49 West Virginia  WV         South    1852994    27
## 50     Wisconsin  WI North Central    5686986    97
## 51       Wyoming  WY          West     563626     5

#q1: A :the 51 state:

states<-c(murders$state)
states
##  [1] "Alabama"              "Alaska"               "Arizona"             
##  [4] "Arkansas"             "California"           "Colorado"            
##  [7] "Connecticut"          "Delaware"             "District of Columbia"
## [10] "Florida"              "Georgia"              "Hawaii"              
## [13] "Idaho"                "Illinois"             "Indiana"             
## [16] "Iowa"                 "Kansas"               "Kentucky"            
## [19] "Louisiana"            "Maine"                "Maryland"            
## [22] "Massachusetts"        "Michigan"             "Minnesota"           
## [25] "Mississippi"          "Missouri"             "Montana"             
## [28] "Nebraska"             "Nevada"               "New Hampshire"       
## [31] "New Jersey"           "New Mexico"           "New York"            
## [34] "North Carolina"       "North Dakota"         "Ohio"                
## [37] "Oklahoma"             "Oregon"               "Pennsylvania"        
## [40] "Rhode Island"         "South Carolina"       "South Dakota"        
## [43] "Tennessee"            "Texas"                "Utah"                
## [46] "Vermont"              "Virginia"             "Washington"          
## [49] "West Virginia"        "Wisconsin"            "Wyoming"
total_murder_state<-c(murders$total)
total_murder_state
##  [1]  135   19  232   93 1257   65   97   38   99  669  376    7   12  364  142
## [16]   21   63  116  351   11  293  118  413   53  120  321   12   32   84    5
## [31]  246   67  517  286    4  310  111   36  457   16  207    8  219  805   22
## [46]    2  250   93   27   97    5

B: . The murder rates for all 50 states and DC.

murders_rates<-c(murders$rates)
murders_rates
## NULL

C: The state name, the abbreviation of the state name, the state’s region, and the state’s population and total number of murders for 2010.

states_name<-c(murders$state)
states_name
##  [1] "Alabama"              "Alaska"               "Arizona"             
##  [4] "Arkansas"             "California"           "Colorado"            
##  [7] "Connecticut"          "Delaware"             "District of Columbia"
## [10] "Florida"              "Georgia"              "Hawaii"              
## [13] "Idaho"                "Illinois"             "Indiana"             
## [16] "Iowa"                 "Kansas"               "Kentucky"            
## [19] "Louisiana"            "Maine"                "Maryland"            
## [22] "Massachusetts"        "Michigan"             "Minnesota"           
## [25] "Mississippi"          "Missouri"             "Montana"             
## [28] "Nebraska"             "Nevada"               "New Hampshire"       
## [31] "New Jersey"           "New Mexico"           "New York"            
## [34] "North Carolina"       "North Dakota"         "Ohio"                
## [37] "Oklahoma"             "Oregon"               "Pennsylvania"        
## [40] "Rhode Island"         "South Carolina"       "South Dakota"        
## [43] "Tennessee"            "Texas"                "Utah"                
## [46] "Vermont"              "Virginia"             "Washington"          
## [49] "West Virginia"        "Wisconsin"            "Wyoming"
states_abb<-c(murders$abb)
states_abb
##  [1] "AL" "AK" "AZ" "AR" "CA" "CO" "CT" "DE" "DC" "FL" "GA" "HI" "ID" "IL" "IN"
## [16] "IA" "KS" "KY" "LA" "ME" "MD" "MA" "MI" "MN" "MS" "MO" "MT" "NE" "NV" "NH"
## [31] "NJ" "NM" "NY" "NC" "ND" "OH" "OK" "OR" "PA" "RI" "SC" "SD" "TN" "TX" "UT"
## [46] "VT" "VA" "WA" "WV" "WI" "WY"
murders_region<-c(murders$region)
murders_region
##  [1] South         West          West          South         West         
##  [6] West          Northeast     South         South         South        
## [11] South         West          West          North Central North Central
## [16] North Central North Central South         South         Northeast    
## [21] South         Northeast     North Central North Central South        
## [26] North Central West          North Central West          Northeast    
## [31] Northeast     West          Northeast     South         North Central
## [36] North Central South         West          Northeast     Northeast    
## [41] South         North Central South         South         West         
## [46] Northeast     South         West          South         North Central
## [51] West         
## Levels: Northeast South North Central West
states_population<-c(murders$population)
states_population
##  [1]  4779736   710231  6392017  2915918 37253956  5029196  3574097   897934
##  [9]   601723 19687653  9920000  1360301  1567582 12830632  6483802  3046355
## [17]  2853118  4339367  4533372  1328361  5773552  6547629  9883640  5303925
## [25]  2967297  5988927   989415  1826341  2700551  1316470  8791894  2059179
## [33] 19378102  9535483   672591 11536504  3751351  3831074 12702379  1052567
## [41]  4625364   814180  6346105 25145561  2763885   625741  8001024  6724540
## [49]  1852994  5686986   563626
total_murders_2010<-sum(murders$murder_2010)
total_murders_2010
## [1] 0

str shows no relevant information:

str(murders)
## 'data.frame':    51 obs. of  5 variables:
##  $ state     : chr  "Alabama" "Alaska" "Arizona" "Arkansas" ...
##  $ abb       : chr  "AL" "AK" "AZ" "AR" ...
##  $ region    : Factor w/ 4 levels "Northeast","South",..: 2 4 4 2 4 4 1 2 2 2 ...
##  $ population: num  4779736 710231 6392017 2915918 37253956 ...
##  $ total     : num  135 19 232 93 1257 ...

#q2:What are the column names used by the data frame for these fve variables?

column_name<-colnames(murders)
column_name
## [1] "state"      "abb"        "region"     "population" "total"

q3:Use the accessor $ to extract the state abbreviations and assign them to the object a. What is the class of this object?

a<-(murders$abb)
a
##  [1] "AL" "AK" "AZ" "AR" "CA" "CO" "CT" "DE" "DC" "FL" "GA" "HI" "ID" "IL" "IN"
## [16] "IA" "KS" "KY" "LA" "ME" "MD" "MA" "MI" "MN" "MS" "MO" "MT" "NE" "NV" "NH"
## [31] "NJ" "NM" "NY" "NC" "ND" "OH" "OK" "OR" "PA" "RI" "SC" "SD" "TN" "TX" "UT"
## [46] "VT" "VA" "WA" "WV" "WI" "WY"
class(a)
## [1] "character"

#q4:Now use the square brackets to extract the state abbreviations and assign them to the object b. Use the identical function to determine if a and b are the same.

b<-murders[[" states_abbreviation"]]
b
## NULL
a==b
## logical(0)

#q5: . We saw that the region column stores a factor. You can corroborate this by typing:

class(murders$region)
## [1] "factor"
levels(murders$region)
## [1] "Northeast"     "South"         "North Central" "West"
length(murders$region)
## [1] 51
length(levels(murders$region))
## [1] 4

#q6:The function table takes a vector and returns the frequency of each element. You can quickly see how many states are in each region by applying this function. Use this function in one line of code to create a table of states per region.

table(murders$region)
## 
##     Northeast         South North Central          West 
##             9            17            12            13
table(murders$states_data)
## < table of extent 0 >

#q7:1. Use the function c to create a vector with the average high temperatures in January for Beijing, Lagos,Paris, Rio de Janeiro, San Juan and Toronto, which are 35, 88, 42, 84, 81, and 30 degrees Fahrenheit.

temp<-c(35, 88, 42, 84, 81,30)
temp
## [1] 35 88 42 84 81 30

#q8: Now create a vector with the city names and call the object city.

city<-c("Beijing","Lagos","Paris", "Rio de Janeiro","San Juan","Toronto")
city
## [1] "Beijing"        "Lagos"          "Paris"          "Rio de Janeiro"
## [5] "San Juan"       "Toronto"

q9:Use the names function and the objects defned in the previous exercises to associate the temperature data with its corresponding city

city<-c("Beijing","Lagos","Paris", "Rio de Janeiro","San Juan","Toronto")
temp<-c(35, 88, 42, 84, 81,30)
names(temp)<-city
temp
##        Beijing          Lagos          Paris Rio de Janeiro       San Juan 
##             35             88             42             84             81 
##        Toronto 
##             30

#q10:Use the [ and : operators to access the temperature of the first three cities on the list.

first_three_tempreture<-temp[1:3]
first_three_tempreture
## Beijing   Lagos   Paris 
##      35      88      42

#q11:. Use the [ operator to access the temperature of Paris and San Juan.

Paris_SanJuan_tempreture<-temp[c(3:5)]
Paris_SanJuan_tempreture
##          Paris Rio de Janeiro       San Juan 
##             42             84             81

#q12:. Use the : operator to create a sequence of numbers 12, 13, 14,…, 73.

sequence<-(12:73)
sequence
##  [1] 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
## [26] 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
## [51] 62 63 64 65 66 67 68 69 70 71 72 73

#q13:Create a vector containing all the positive odd numbers smaller than 100.

odd_number<-seq(1,99,by=2)
odd_number
##  [1]  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
## [26] 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99

q14:Create a vector of numbers that starts at 6, does not pass 55, and adds numbers in increments of 4/7:6, 6+4/7, 6+8/7, etc.. How many number does the list have?

numbers<-seq(6,55,by=4/7)
numbers
##  [1]  6.000000  6.571429  7.142857  7.714286  8.285714  8.857143  9.428571
##  [8] 10.000000 10.571429 11.142857 11.714286 12.285714 12.857143 13.428571
## [15] 14.000000 14.571429 15.142857 15.714286 16.285714 16.857143 17.428571
## [22] 18.000000 18.571429 19.142857 19.714286 20.285714 20.857143 21.428571
## [29] 22.000000 22.571429 23.142857 23.714286 24.285714 24.857143 25.428571
## [36] 26.000000 26.571429 27.142857 27.714286 28.285714 28.857143 29.428571
## [43] 30.000000 30.571429 31.142857 31.714286 32.285714 32.857143 33.428571
## [50] 34.000000 34.571429 35.142857 35.714286 36.285714 36.857143 37.428571
## [57] 38.000000 38.571429 39.142857 39.714286 40.285714 40.857143 41.428571
## [64] 42.000000 42.571429 43.142857 43.714286 44.285714 44.857143 45.428571
## [71] 46.000000 46.571429 47.142857 47.714286 48.285714 48.857143 49.428571
## [78] 50.000000 50.571429 51.142857 51.714286 52.285714 52.857143 53.428571
## [85] 54.000000 54.571429
length_number<-length(numbers)
length_number
## [1] 86

#q15:What is the class of the following object a <- seq(1, 10, 0.5)?

a <- seq(1, 10, 0.5)
a
##  [1]  1.0  1.5  2.0  2.5  3.0  3.5  4.0  4.5  5.0  5.5  6.0  6.5  7.0  7.5  8.0
## [16]  8.5  9.0  9.5 10.0
class(a)
## [1] "numeric"

#q16:What is the class of the following object a <- seq(1, 10)?

a <- seq(1, 10)
a
##  [1]  1  2  3  4  5  6  7  8  9 10
class(a)
## [1] "integer"

#q17:The class of class(a<-1) is numeric, not integer. R defaults to numeric and to force an integer, you need to add the letter L. Confrm that the class of 1L is integer

x<-1L
x
## [1] 1
class(x)
## [1] "integer"

#q18:Defne the following vector:x <- c(“1”, “3”, “5”)and coerce it to get integers

x <- c("1", "3", "5")
x <-as.integer(x)
x
## [1] 1 3 5

Note that the echo = FALSE parameter was added to the code chunk to prevent printing of the R code that generated the plot.