topic Re: Is a LIBNAME really needed to read in a file (SAS OnDemand)? in SAS Studio

Is a LIBNAME really needed to read in a file (SAS OnDemand)?

doylejm — Wed, 23 Jan 2019 02:38:58 GMT

I have my students using SAS OnDemand for some simple tasks. Is it really necessary to create a library and a LIBNAME for the datafile? I uploaded a .csv file to a folder in my OnDemand folders, and then use the path and filename in the PROC IMPORT DATAFILE" " command as shown below. I typically do the same thing with SAS on the PC. I guess I am asking why I need a Library and LIBNAME for a simple program that imports a single, simple datafile? Doesn't the path do the same thing....why the extra steps?

Thank you

doylejm

PROC IMPORT DATAFILE="/home/doylejm/Ec385S19/house.csv"
DBMS=csv
OUT=mydat replace;
RUN;

PROC CONTENTS;
RUN;

DATA mydat2;
SET mydat;

NEWPRICE = PRICE*1000;

PROC PRINT;
TITLE 'TABLE 4.1 HOUSE PRICES';
RUN;

Re: Is a LIBNAME really needed to read in a file (SAS OnDemand)?

Reeza — Wed, 23 Jan 2019 03:21:41 GMT

You don't need one, but it's helpful for avoiding to have to re-read the same data set every time.

Re: Is a LIBNAME really needed to read in a file (SAS OnDemand)?

Tom — Wed, 23 Jan 2019 06:33:27 GMT

A LIBNAME statement is used for a different thing than the DATAFILE= option on PROC IMPORT.

There is a big difference between storing a SAS dataset and storing a delimited text file, such as a CSV file.

A CSV file does not contain any metadata about the variables. At best it has a header row that can be used as source for guessing what names to use for the variables.

A SAS dataset will allow you to store the variable type, length. Attach any formats or labels to the variables.

Then when you want to use it again you can skip the step of converting the text file into data. Instead you can use a libname statement to create a libref that points to the folder that contains the dataset. Or you can just skip the LIBNAME statement and use the name of the file that contains the dataset.

So on day 1 you run this code:

PROC IMPORT
  DATAFILE="/home/doylejm/Ec385S19/house.csv" DBMS=csv
  OUT="/home/doylejm/Ec385S19/house"  replace
;
RUN;

Then on day 1,2,3,..... you can just start with this code:

data for_print;
  set "/home/doylejm/Ec385S19/house"  ;
  newprice = price*100;
run;

proc print data=for_print;
title  'TABLE 4.1 HOUSE PRICES';
run;
title;

Re: Is a LIBNAME really needed to read in a file (SAS OnDemand)?

ballardw — Wed, 23 Jan 2019 18:16:41 GMT

Any SAS data set is always stored in a Library somewhere. If you only use a one level name the default is the WORK library which means that the data set will be removed at the end of the SAS session by default. So assigning a specific library location other than work means that you can continue where you left off and all of the data is available after a libname statement is used to reference the location(s). There are several ways depending on your installation to have libraries assigned at start of your SAS session.