Tanya, hi! You attempt to solve Boundary Value Problem. Sorry, I'm think -> it's initial value problems, and tell you
about system linearized equations and their matrix and ther eigen values problem.
At function w = linshoot ( coeff, a, b, n, alpha, beta )..., and so on I'm not see all program.
Only function w = linshoot ( coeff, a, b, n, alpha, beta ).
Let's look at the problem statement and the solution algorithm. All the best, Paul.