topic Re: Get list of all variables within a module as a variable in SAS/IML Software and Matrix Computations

Get list of all variables within a module as a variable

AThomalla — Sat, 16 Nov 2019 16:46:24 GMT

Hi,

I would like to write code which executes some module, but in the same time automatically prints all variables/matrices or stores them in an excel sheet. For doing that, first I would need some functionality like "SHOW" which gives the local variables within the module, so that I can make a loop accross the variables and print and export them to excel. So in my opinion the key difficulty here is to get and store a list of all variables within a module. Is that possible with some IML functionalities?

Example:

proc iml;

start example(input_var);

var1 = input_var #2;
var2 = input_var + 2;

measure = var1 || var2;

return(measure)
finish;

M = {1,2};
test = example(M);

quit;

In that example I would like to define a module or a macro with which I can execute the module "example" with additional requirement that while executing all local variables (so input, var1, var2, measure) are printed automatically.

Thanks!

Re: Get list of all variables within a module as a variable

AThomalla — Sat, 16 Nov 2019 17:47:06 GMT

I think, the answer is the

STORAGE Function.

So first I would have to store all Matrices in a specific library (store _all_) and then apply the storage() function the get the list.

Re: Get list of all variables within a module as a variable

Rick_SAS — Sun, 17 Nov 2019 21:25:56 GMT

I guess I'd use ODS OUTPUT to store the results of the SHOW command in a data set. Then read in the results and parse the file to obtain the variable name. Maybe this will give you are start (only partially tested):

%macro PrintLocalVars();
   ods exclude iml.show; 
   ods output iml.show=showvars;   /* store SHOW table */
      show names;
   ods output close;
   ods exclude none;
   use showvars; read all var {batch}; close;
   call delete(showvars);
   _ndx = loc(batch^=' ');          /* delete any blank lines */
   if ncol(_ndx)>0 then batch=batch[_ndx];
   _b = batch[3:(nrow(batch)-1)];   /* get rid of  headers and end message */
   _LocalVars = scan(_b, 1, ' ');
   print _LocalVars;
   free batch _ndx _b _LocalVars;
%mend;

proc iml;

x = 1; y = 2; z = 3;
%PrintLocalVars();

free x y z varnames;
a = 1; b = 2; c = 3;
%PrintLocalVars();

/* get local vars inside module */
start example(input_var);
   var1 = input_var #2;
   var2 = input_var + 2;
   measure = var1 || var2;
   call execute("%PrintLocalVars()"); 
   return(measure);
finish;

M = {1,2};
test = example(M);

quit;