Hi everyone I've been doing maths for quite a while now, but have never done any programming until recently. What I'm finding difficult is how you go from an initial value/boundary value problem on a bit of paper to a piece of code that will approximate the equation. I've done a bit of book work on numerical methods (Euler’s midpoint/trapezoidal methods, Runge–Kutta methods) so understand the basics, but would like a more thorough knowledge. Can anyone suggest any good sites/documents/books that give examples or explanations? Searching online brings up loads of pre-prepared Fortran codes to solve all sorts of things, but I want to know how these codes were created, why they chose the methods they did etc. Thanks very much in advance.