1D advection-diffusion--need to check my code; any suggestions? Hi everyone: I am teaching myself transport/programming, and have created a simple program for 1-D advection-diffusion (constant velocity, diffusion coefficient, central differencing, Crank-Nicolson). I would like to check that my code is working properly and would appreciate any advice about how to go about this. I have not been successful on Google at finding code that others have written... If anyone can direct me or provide advice about getting an analytical solution, I would be very grateful. An EXCEL-based spreadsheet or a Matlab or a c++ implementation would be useful; I am not a Fortran or C user.