Hello All, I'm new to the forum and new to fortran as well. I've been trying to create a method for implementing the steepest descent method for optimization. I've been able to create the code for a fixed step size and it worked beaufitully, but I can not seem to be able to find the optimal step size. My teacher asked us to use a cubic interpolation for it, and I was able to create a system using a stepsize interval and finding the best in the interval, but in the program, the loop to find this step size crashes. If needed, I can post the code to what I've done, but it's kind of messy( I am VERY unorganized). lol Any tips?