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Karl · Guest

Hi,

I get an error invalid floating point operation using StdDev with BDS
2006. Not every time, but sometimes (therefore the loop in the code).

#include "Math.hpp"
void __fastcall TForm1::Button1Click(TObject *Sender)
{
double *data = new double[3];
for (int i=-1000; i<1000; i++)
{
data[0] = 0.75277265271037 + i*1E-19;
data[1] = 0.75277265271037 + i*1E-19;
data[2] = 0.75277265271037 + i*1E-19;
long double sd = StdDev(data, 2);
}
delete[] data;
}

Does anybody understand this?

After my analysis the calculation of Variance(...), which is used in
StdDev(...), gives a negative value, and the sqrt of a neg. value gives
the error. Actually I get the data from somewhere else, so I should not
change the numbers in just 0.75277265271037.

Karl