R to SAS cheatsheet - a collection of snippets

This list was created to quickly translate a R code to its equivalent in SAS.

I wrote these snippets to be as short as possible and to reflect my own coding style. There are many ways to skin a cat: you might know another way to write a similar code in R and SAS. Don't hesitate to drop me a line if you know a better way.

Data loading

Loading inline data

Typically copy-and-paste a few lines of data in CSV format.

R:

d = read.table(sep=',', text='AMC   ,  22 ,3 ,2930 ,0
AMC   ,  17 ,3 ,3350 ,0
AMC   ,  22 , ,2640 ,0
Audi  ,  17 ,5 ,2830 ,1
Audi  ,  23 ,3 ,2070 ,1
BMW   ,  25 ,4 ,2650 ,1
Buick ,  20 ,3 ,3250 ,0
Buick ,  15 ,4 ,4080 ,0
Buick ,  18 ,3 ,3670 ,0
Buick ,  26 , ,2230, 0
Buick ,  20 ,3 ,3280 ,0
Buick ,  16 ,3 ,3880 ,0
Buick ,  19 ,3 ,3400 ,0')
colnames(d) = c('make', 'mpg', 'rep78', 'weight', 'foreign')

SAS:

DATA d;
INFILE CARDS DELIMITER=',';
  INPUT make $  mpg rep78 weight foreign;
  CARDS;
  AMC   ,  22 ,3 ,2930 ,0
  AMC   ,  17 ,3 ,3350 ,0
  AMC   ,  22 , ,2640 ,0
  Audi  ,  17 ,5 ,2830 ,1
  Audi  ,  23 ,3 ,2070 ,1
  BMW   ,  25 ,4 ,2650 ,1
  Buick ,  20 ,3 ,3250 ,0
  Buick ,  15 ,4 ,4080 ,0
  Buick ,  18 ,3 ,3670 ,0
  Buick ,  26 , ,2230, 0
  Buick ,  20 ,3 ,3280 ,0
  Buick ,  16 ,3 ,3880 ,0
  Buick ,  19 ,3 ,3400 ,0
  ;

Caveat: use $ to indicate a String field.

Loading data from a file

In this example, the file in CSV format.

R:

d = read.csv('example.csv')

SAS:

PROC IMPORT DATAFILE="example.csv";
     OUT=d;
     DBMS=CSV;

Caveat: depending on your platform, you might need to enter FILENAME CSV "example.csv" TERMSTR=CRLF; (windows carriage returns) or FILENAME CSV "example.csv" TERMSTR=LF; (linux) prior to importing.

Common data manipulation

sorting one dataset

In this example, dataset is a data.frame/DATA with one column named thekey and some other columns containing different values.

R:

sorted_dataset = dataset[order(dataset$thekey),]

SAS:

PROC SORT DATA=sorted_dataset;
BY thekey;

Merging two datasets

R:

merged_dataset = merge(first_dataset, second_dataset, by='the_key')

SAS:

PROC SORT DATA=first_dataset;
BY the_key;

PROC SORT DATA=second_dataset;
BY the_key;

DATA merged_dataset;
MERGE first_dataset second_dataset;
BY the_key;

Huge caveat: MERGE requires the data to be sorted. To avoid sorting beforehand, it is possible to make the merge with PROC SQL:

PROC SQL;
  CREATE TABLE merged_dataset AS
  SELECT * 
  FROM first_dataset
  FULL JOIN second_dataset
  ON first_dataset.the_key = second_dataset.the_key;

Concatenating two datasets

R:

both = rbind(first_dataset, second_dataset)

Note: if the columns do not match, invoke rbind.fill instead of rbind (from package plyr).

SAS:

DATA both;
SET first_dataset second_dataset;
RUN;

Data statistics

Showing summary statistics

R:

summary(d)

SAS:

PROC MEANS DATA=d;