Chapter 2 - Workflow basics

Last updated: 2020-11-21

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Knit directory: r4ds_book/

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Rmd	50ff8a5	sciencificity	2020-08-26	Corrected page flow
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Rmd	865e66f	sciencificity	2020-08-23	Ch1 more complete, plus started Ch2

Workflow …

object_name <- value can be read as “object name gets value”

Find the <- tedious to enter? RStudio has a shortcut Alt + - to enter it for you.

Alternately there’s the great {styler} package that you may use to convert your code to the preferred style.

Go to Tools -> Install Packages and install styler
Else go to the Github page to install.
In your code select the section you want to format (not necessary if you want to do for the entire file).
- Go to Addins
- STYLER
- Choose Style selection or the option appropriate for your task.

Sometime you have an assignment, but you also want to print your variable to view its contents. Do this by surrounding the assignment with ().

( y <- seq(1, 10, length.out = 5) )


[1]  1.00  3.25  5.50  7.75 10.00

Exercises

Why does this code not work?
```
my_variable <- 10
my_varıable
```
```
[1] 10
```
Look carefully! (This may seem like an exercise in pointlessness, but training your brain to notice even the tiniest difference will pay off when programming.)

It doesn’t work because the i in the my_variable has been replaced by another character ı.

Tweak each of the following R commands so that they run correctly:

library(tidyverse)
ggplot(dota = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy))

fliter(mpg, cyl = 8)
filter(diamond, carat > 3)

library(tidyverse)
  ggplot(data = mpg) +
    geom_point(mapping = aes(x = displ, y = hwy))

filter(mpg, cyl == 8)


    # A tibble: 70 x 11
       manufacturer model     displ  year   cyl trans  drv     cty   hwy fl    class
       <chr>        <chr>     <dbl> <int> <int> <chr>  <chr> <int> <int> <chr> <chr>
     1 audi         a6 quatt~   4.2  2008     8 auto(~ 4        16    23 p     mids~
     2 chevrolet    c1500 su~   5.3  2008     8 auto(~ r        14    20 r     suv  
     3 chevrolet    c1500 su~   5.3  2008     8 auto(~ r        11    15 e     suv  
     4 chevrolet    c1500 su~   5.3  2008     8 auto(~ r        14    20 r     suv  
     5 chevrolet    c1500 su~   5.7  1999     8 auto(~ r        13    17 r     suv  
     6 chevrolet    c1500 su~   6    2008     8 auto(~ r        12    17 r     suv  
     7 chevrolet    corvette    5.7  1999     8 manua~ r        16    26 p     2sea~
     8 chevrolet    corvette    5.7  1999     8 auto(~ r        15    23 p     2sea~
     9 chevrolet    corvette    6.2  2008     8 manua~ r        16    26 p     2sea~
    10 chevrolet    corvette    6.2  2008     8 auto(~ r        15    25 p     2sea~
    # ... with 60 more rows

filter(diamonds, carat > 3)


    # A tibble: 32 x 10
       carat cut     color clarity depth table price     x     y     z
       <dbl> <ord>   <ord> <ord>   <dbl> <dbl> <int> <dbl> <dbl> <dbl>
     1  3.01 Premium I     I1       62.7    58  8040  9.1   8.97  5.67
     2  3.11 Fair    J     I1       65.9    57  9823  9.15  9.02  5.98
     3  3.01 Premium F     I1       62.2    56  9925  9.24  9.13  5.73
     4  3.05 Premium E     I1       60.9    58 10453  9.26  9.25  5.66
     5  3.02 Fair    I     I1       65.2    56 10577  9.11  9.02  5.91
     6  3.01 Fair    H     I1       56.1    62 10761  9.54  9.38  5.31
     7  3.65 Fair    H     I1       67.1    53 11668  9.53  9.48  6.38
     8  3.24 Premium H     I1       62.1    58 12300  9.44  9.4   5.85
     9  3.22 Ideal   I     I1       62.6    55 12545  9.49  9.42  5.92
    10  3.5  Ideal   H     I1       62.8    57 12587  9.65  9.59  6.03
    # ... with 22 more rows

Press Alt + Shift + K. What happens? How can you get to the same place using the menus?

It opens the shortcuts popup page. You may close the page by pressing ESC.

To get there through the menus go to Tools -> Keyboard Shortcuts Help

sessionInfo()

R version 3.6.3 (2020-02-29)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19042)

Matrix products: default

locale:
[1] LC_COLLATE=English_South Africa.1252  LC_CTYPE=English_South Africa.1252   
[3] LC_MONETARY=English_South Africa.1252 LC_NUMERIC=C                         
[5] LC_TIME=English_South Africa.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] flair_0.0.2     forcats_0.5.0   stringr_1.4.0   dplyr_1.0.2    
 [5] purrr_0.3.4     readr_1.4.0     tidyr_1.1.2     tibble_3.0.3   
 [9] ggplot2_3.3.2   tidyverse_1.3.0 workflowr_1.6.2

loaded via a namespace (and not attached):
 [1] tidyselect_1.1.0 xfun_0.13        haven_2.3.1      colorspace_1.4-1
 [5] vctrs_0.3.2      generics_0.0.2   htmltools_0.5.0  yaml_2.2.1      
 [9] utf8_1.1.4       rlang_0.4.8      later_1.0.0      pillar_1.4.6    
[13] withr_2.2.0      glue_1.4.2       DBI_1.1.0        dbplyr_2.0.0    
[17] modelr_0.1.8     readxl_1.3.1     lifecycle_0.2.0  munsell_0.5.0   
[21] gtable_0.3.0     cellranger_1.1.0 rvest_0.3.6      evaluate_0.14   
[25] labeling_0.3     knitr_1.28       ps_1.3.2         httpuv_1.5.2    
[29] fansi_0.4.1      broom_0.7.2      Rcpp_1.0.4.6     promises_1.1.0  
[33] backports_1.1.6  scales_1.1.0     jsonlite_1.7.1   farver_2.0.3    
[37] fs_1.5.0         hms_0.5.3        digest_0.6.27    stringi_1.5.3   
[41] rprojroot_1.3-2  grid_3.6.3       cli_2.1.0        tools_3.6.3     
[45] magrittr_1.5     crayon_1.3.4     whisker_0.4      pkgconfig_2.0.3 
[49] ellipsis_0.3.1   xml2_1.3.2       reprex_0.3.0     lubridate_1.7.9 
[53] assertthat_0.2.1 rmarkdown_2.4    httr_1.4.2       rstudioapi_0.11 
[57] R6_2.4.1         git2r_0.26.1     compiler_3.6.3

Chapter 2 - Workflow basics

Vebash Naidoo

23/08/2020

Workflow …

Exercises