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##      speed           dist       
##  Min.   : 4.0   Min.   :  2.00  
##  1st Qu.:12.0   1st Qu.: 26.00  
##  Median :15.0   Median : 36.00  
##  Mean   :15.4   Mean   : 42.98  
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#8.1
library(tidyverse)
## -- Attaching packages ------------------------------------------------ tidyverse 1.2.1 --
## v ggplot2 3.0.0     v purrr   0.2.5
## v tibble  1.4.2     v dplyr   0.7.6
## v tidyr   0.8.1     v stringr 1.3.1
## v readr   1.1.1     v forcats 0.3.0
## -- Conflicts --------------------------------------------------- tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()
mtcars
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
mtcars.tb <- as_tibble(mtcars)
mtcars.tb
## # A tibble: 32 x 11
##      mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
##  * <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
##  1  21       6  160    110  3.9   2.62  16.5     0     1     4     4
##  2  21       6  160    110  3.9   2.88  17.0     0     1     4     4
##  3  22.8     4  108     93  3.85  2.32  18.6     1     1     4     1
##  4  21.4     6  258    110  3.08  3.22  19.4     1     0     3     1
##  5  18.7     8  360    175  3.15  3.44  17.0     0     0     3     2
##  6  18.1     6  225    105  2.76  3.46  20.2     1     0     3     1
##  7  14.3     8  360    245  3.21  3.57  15.8     0     0     3     4
##  8  24.4     4  147.    62  3.69  3.19  20       1     0     4     2
##  9  22.8     4  141.    95  3.92  3.15  22.9     1     0     4     2
## 10  19.2     6  168.   123  3.92  3.44  18.3     1     0     4     4
## # ... with 22 more rows
mtcars.tb %>% slice(1:5, )
## # A tibble: 5 x 11
##     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
##   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1  21       6   160   110  3.9   2.62  16.5     0     1     4     4
## 2  21       6   160   110  3.9   2.88  17.0     0     1     4     4
## 3  22.8     4   108    93  3.85  2.32  18.6     1     1     4     1
## 4  21.4     6   258   110  3.08  3.22  19.4     1     0     3     1
## 5  18.7     8   360   175  3.15  3.44  17.0     0     0     3     2
mtcars.tb %>% slice(28:32)
## # A tibble: 5 x 11
##     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
##   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1  30.4     4  95.1   113  3.77  1.51  16.9     1     1     5     2
## 2  15.8     8 351     264  4.22  3.17  14.5     0     1     5     4
## 3  19.7     6 145     175  3.62  2.77  15.5     0     1     5     6
## 4  15       8 301     335  3.54  3.57  14.6     0     1     5     8
## 5  21.4     4 121     109  4.11  2.78  18.6     1     1     4     2
mtcars.tb %>% count()
## # A tibble: 1 x 1
##       n
##   <int>
## 1    32
mtcars.tb %>% select(mpg)
## # A tibble: 32 x 1
##      mpg
##  * <dbl>
##  1  21  
##  2  21  
##  3  22.8
##  4  21.4
##  5  18.7
##  6  18.1
##  7  14.3
##  8  24.4
##  9  22.8
## 10  19.2
## # ... with 22 more rows
mtcars.tb %>%
  filter(cyl == 6) %>%
  select(mpg)
## # A tibble: 7 x 1
##     mpg
##   <dbl>
## 1  21  
## 2  21  
## 3  21.4
## 4  18.1
## 5  19.2
## 6  17.8
## 7  19.7
mtcars.tb %>% 
  filter(cyl == 6)
## # A tibble: 7 x 11
##     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
##   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1  21       6  160    110  3.9   2.62  16.5     0     1     4     4
## 2  21       6  160    110  3.9   2.88  17.0     0     1     4     4
## 3  21.4     6  258    110  3.08  3.22  19.4     1     0     3     1
## 4  18.1     6  225    105  2.76  3.46  20.2     1     0     3     1
## 5  19.2     6  168.   123  3.92  3.44  18.3     1     0     4     4
## 6  17.8     6  168.   123  3.92  3.44  18.9     1     0     4     4
## 7  19.7     6  145    175  3.62  2.77  15.5     0     1     5     6
mtcars.tb %>%
  filter(mpg > 25) %>%
  select(mpg, cyl)
## # A tibble: 6 x 2
##     mpg   cyl
##   <dbl> <dbl>
## 1  32.4     4
## 2  30.4     4
## 3  33.9     4
## 4  27.3     4
## 5  26       4
## 6  30.4     4
#8.2
diamonds.tb <- as_tibble(diamonds)
diamonds.tb
## # A tibble: 53,940 x 10
##    carat cut       color clarity depth table price     x     y     z
##    <dbl> <ord>     <ord> <ord>   <dbl> <dbl> <int> <dbl> <dbl> <dbl>
##  1 0.23  Ideal     E     SI2      61.5    55   326  3.95  3.98  2.43
##  2 0.21  Premium   E     SI1      59.8    61   326  3.89  3.84  2.31
##  3 0.23  Good      E     VS1      56.9    65   327  4.05  4.07  2.31
##  4 0.290 Premium   I     VS2      62.4    58   334  4.2   4.23  2.63
##  5 0.31  Good      J     SI2      63.3    58   335  4.34  4.35  2.75
##  6 0.24  Very Good J     VVS2     62.8    57   336  3.94  3.96  2.48
##  7 0.24  Very Good I     VVS1     62.3    57   336  3.95  3.98  2.47
##  8 0.26  Very Good H     SI1      61.9    55   337  4.07  4.11  2.53
##  9 0.22  Fair      E     VS2      65.1    61   337  3.87  3.78  2.49
## 10 0.23  Very Good H     VS1      59.4    61   338  4     4.05  2.39
## # ... with 53,930 more rows
diamonds.tb %>%
  slice(1:5,)
## # A tibble: 5 x 10
##   carat cut     color clarity depth table price     x     y     z
##   <dbl> <ord>   <ord> <ord>   <dbl> <dbl> <int> <dbl> <dbl> <dbl>
## 1 0.23  Ideal   E     SI2      61.5    55   326  3.95  3.98  2.43
## 2 0.21  Premium E     SI1      59.8    61   326  3.89  3.84  2.31
## 3 0.23  Good    E     VS1      56.9    65   327  4.05  4.07  2.31
## 4 0.290 Premium I     VS2      62.4    58   334  4.2   4.23  2.63
## 5 0.31  Good    J     SI2      63.3    58   335  4.34  4.35  2.75
diamonds.tb %>%
  count()
## # A tibble: 1 x 1
##       n
##   <int>
## 1 53940
diamonds.tb %>%
  filter(cut == "Very Good") %>%
  count()
## # A tibble: 1 x 1
##       n
##   <int>
## 1 12082
diamonds.tb %>%
  filter(carat > 3.0) %>%
  count()
## # A tibble: 1 x 1
##       n
##   <int>
## 1    32
diamonds.tb %>%
  filter(color == "D") %>%
  select(color, cut)
## # A tibble: 6,775 x 2
##    color cut      
##    <ord> <ord>    
##  1 D     Very Good
##  2 D     Very Good
##  3 D     Very Good
##  4 D     Good     
##  5 D     Good     
##  6 D     Premium  
##  7 D     Premium  
##  8 D     Ideal    
##  9 D     Ideal    
## 10 D     Very Good
## # ... with 6,765 more rows
diamonds.tb %>%
  summarise(mean(price))
## # A tibble: 1 x 1
##   `mean(price)`
##           <dbl>
## 1         3933.
#8.3
mtcars.tb %>%
  group_by(cyl) %>%
  count()
## # A tibble: 3 x 2
## # Groups:   cyl [3]
##     cyl     n
##   <dbl> <int>
## 1     4    11
## 2     6     7
## 3     8    14
mtcars.tb %>%
  group_by(cyl) %>%
  summarise(mpg.mean = mean(mpg), disp.mean = mean(disp))
## # A tibble: 3 x 3
##     cyl mpg.mean disp.mean
##   <dbl>    <dbl>     <dbl>
## 1     4     26.7      105.
## 2     6     19.7      183.
## 3     8     15.1      353.
diamonds.tb %>%
  group_by(cut) %>%
  summarise(max.price = max(price), min.price = min(price))
## # A tibble: 5 x 3
##   cut       max.price min.price
##   <ord>         <dbl>     <dbl>
## 1 Fair          18574       337
## 2 Good          18788       327
## 3 Very Good     18818       336
## 4 Premium       18823       326
## 5 Ideal         18806       326
diamonds.tb %>%
  group_by(color) %>%
  summarise(max.price = max(price), mean.price = mean(price), min.price = min(price))
## # A tibble: 7 x 4
##   color max.price mean.price min.price
##   <ord>     <dbl>      <dbl>     <dbl>
## 1 D         18693      3170.       357
## 2 E         18731      3077.       326
## 3 F         18791      3725.       342
## 4 G         18818      3999.       354
## 5 H         18803      4487.       337
## 6 I         18823      5092.       334
## 7 J         18710      5324.       335