Non-linear differential equation

[Heimisson]

Hi I'm writing a function (matlab) in my numerical analysis class that descripes in a certain way a non-linear differential equations with Robin BC that I will then feed to a program that uses finite difference method to solve it. It seems to work but I wanted to look for a site or program that could solve some example equations numerically so I can be sure that it's working correctly. WolframAlpha doesn't seem to handle Robin BC and by googling I only found programs that don't work on mac.

thanks

 

[Heimisson]

Never mind I found a solution to the equation, although a trustworthy program would be useful.