I have programmed a loop calculation to obtain the minimum value of the (Pf) variable. This variable is a function of three independent parameters (i, k, and θ). To do these things I have issues as attached. Your help is deeply appreciated.
Your Tau.Thetaz[i,j,k assignment causes an error because you cannot have a three-dimensional array in Mathcad, nor in Prime. You are limited to 2-dimensional array's (matrices). But every array element can be an array itself.
The result of your program cannot, for the same reason, be stored in Pw.f[i.j.k
Then, regarding the 'minimum of Pf: Do you want the minimum of the 101 Fp values, then you better take that after the FOR loop.
And finally, you program will deliver one answer, independent of all your Pf values. It's value is 5550 psi. But as stated, it cannot be stored.
I attach the file converted to Prime6, maybe others can help you.
Rather than matrices, you should define functions.
Rather cumbersome in Prime Express, but you can see why functions are more versatile.