When I read papers of compressed sensing, sparse representation and whatever requiring optimization of a cost function, I just find the final results as an iterative equation or so which will converge after few iterations and solve the problem.
But, when I try to add some other constraints to the cost function, I cannot derive the iterative or whatever the solution is and I know that is for my poor mathematics.
Can anyone lead me to a book or so to read and understand how to solve these types of mathematics? What book chapter? What tutorial?