Geometric and weighted mean

[salvomic]

Could this code be good?
No error correction (for 0, negative numbers) in it.

Code:


// Geometric mean
// list1 mustn't have 0 and must contain positive numbers
EXPORT gmean(list1)
BEGIN
RETURN surd(ΠLIST(list1),SIZE(list1));
END;

// Weighted mean
// list1 items, wlist weights
EXPORT wmean(list1, wlist)
BEGIN
RETURN ΣLIST(list1*wlist)/ΣLIST(wlist);
END;

// Harmonic mean
// list1 mustn't contain 0
EXPORT hmean(list1)
BEGIN
RETURN (ΣLIST((list1)^(-1)))^(-1)*SIZE(list1);
END;

With the Carlos' lists list1={5.2, 8.2,7.4,5.7}, wlist={3,1,2,4}:

mean(list1) = 6.625
median(list1) = 6.55

gmean(list1) = 6.51224817722
wmean(list1, wlist) = 6.14
hmean(list1) = 6.40171419012

Question for Bernard: are there those means in XCAS?

EDIT:: thanks to Carlos29pz for info: I didn't remember that we can use the already present command mean(list1, list2) to get weighted mean, so please, use my program only for geometric and harmonic means, since those command won't be built-in the Prime.