chickadee » statistics » phi

phi xprocedure

returns the cumulative distribution function (CDF) of the standard normal distribution.

> (do-ec (: x -2 2 0.4)
         (format #t "~4,1f ~,4f~&" x (phi x)))
-2.0 0.0228
-1.6 0.0548
-1.2 0.1151
-0.8 0.2119
-0.4 0.3446
 0.0 0.5000
 0.4 0.6554
 0.8 0.7881
 1.2 0.8849
 1.6 0.9452