Q function (inverse) and erf(c) inverse in CAS

[nbc12]

I'm doing a statistics class this summer, and the CAS on the Prime has been a huge help!

I noticed that the Prime doesn't have these MATLAB functions that we use in class:
qfunc (Q function)
qfuncinv (Inverse Q function)
erfinv (Inverse ERF)
erfcinv (Inverse ERFC)

So I created a CAS program to give me them.

Code:


#cas
QFUNC():=
BEGIN
  erfcinv(x) := normald_icdf(x/2) / -√(2);
  erfinv(x) := erfcinv(1-x);
  qfunc(x) := normald_cdf(-x);
  qfuncinv(x) := -normald_icdf(x);
END;
#end

Feel free to use as you wish. I'm mostly just putting this here so some future stats student can just grab the program.

Maybe these could be included in a future update? It would be helpful to me at least