error in the integration of complex functions (FW10077)

[Helge Gabert]

It seems like the built-in integration routines (int, but also romberg) have trouble with discontinuities. Same result (0) is obtained for int(ft(x,1/x),0,1) or int(ft(x, 10*sin(x)),0,1). Or any other bounds between 0 and 1, for that matter.

It is also interesting that a plot of ceiling(X) and ft(X, ceiling(X)): plot menu: signed area recognizes ft, but if the user attempts to calculate the area between both functions, the result is only for the area between ceiling(X) and the X-axis.

Of course, one can always write his/her own integration routine . . .