Triad sou.

任意の底の対数

proc fcmp outlib = sasuser.funcs.logbase;
  function logbase(x, base);
    return (log(x) / log(base));
  endsub;
run;
options cmplib = sasuser.funcs;

data test;
  a = logbase(48, 7);
  b = logbase(49, 7);
proc print; run;
OBS       a       b

 1     1.98940    2