I write a macro sentence in SAS :
%if abs(%eval(&sigmav-&sigmav_new))<0.001 %then %do;
But there are always errors of abs( ) and std( ). So I wonder whether there are special rules to express the function of abs() and std() in a macro. Hope for your help!
If you want to call a SAS function in a macro (and outside of a data step), you need to enclose it in %sysfunc().