I have implemented the method on p.232 for the evaluation of the incomplete beta function. If I compare my results with Excel,Excelfunction BETAVERT, they differ slightly (the size of difference depends on the values I insert). Which values are correct?

The routing Gammaln which is used to compute the beta function gives the same result as Excel.

Thank you very much for your response.

Annegret

Excel, any version, have only 7 decimals accurate in erf and erfc for some values of argument.

Perhaps Excel is not accurate also for BETAVERT.

Cordialy,

GGendre