First: You should always attach the Mathcad/Prime sheet to your problem description.
Then to the error message:
I think your problem lies with how you create the value 'n' that you use to index the rows of matrix U.i.netto.
This index n is calculated by taking one of the values in the matrix BA and dividing that by steg, which is defined as 0.01.
Let's take an example. One of the BA values is 4.6; divided by steg (0.01) that should result in 460, isn't it?
Well here is what Prime calculates:
OK, that looks like 460, but is it? Let's compare:
Gives a 0 (false, so NOT true), indicating that 4.6/steg is NOT equal to 460. Apparently when n is 4.6/steg, it is not an integer value. How much does it differ:
(This value is in the order of the numerical resolution, due to digital representation of numbers, internally, with a limited number of bits.) So the difference is not much, but still. Prime notices that n in this case is not an integer and flags the error.
Since Mathcad 15 uses much the same numerical methods, I should think that Mathcad 15 would also see such n as not an integer, and flag an error. You say it worked, I wonder what you changed, going from Mathcad to Prime...
What can you do about it? One approach could be:
Increase the values in BA by a factor of 100 and use those, without division by steg, to index the U.i.netto matrix. Everywhere else where you need those 100 times smaller values of the original BA, multiply them by steg.
Success!
Luc
