Hows, Whys and Wherefores of FEM in Quantitative Finance - VII


Do you remember the equation derived in our last blog post ? -


In the finite element world, K is named element stiffness matrix, M is named element mass matrix and f is called the element load vector. As promised in the last post we will analyse these matrices today starting with the element stiffness matrix. First we calculate the gradient vector of


and obtain


Therefore we end up with


To obtain the element matrices, it is necessary to evaluate the integrals just derived. Restricting ourselves to the two-dimensional case, we will now show that this can be done analytically for simple linear triangular elements where we have shown the element shape functions in a recent blog post.




As long as G is constant inside the element, the element mass matrix can be
easily evaluated


and for the load vector we obtain


This series of blog posts summarizes a chapter of the book A Workout in Computational Finance. The next blog post will discuss how to incorporate a time discretisation to our  setup. It will be published on Monday, 22nd of July.