This function compares lu-decomposition and qr-decomposition,
using the pathological matrix given by wilkinson|
usage: Wilkinson(n) and n is the maximal number of unknowns
for the system of equations to be solved
Within the m-File, you can set the flags 'ITER' and 'DISPLAY'
for iterative refinement of the lu-decomposition and for
display of the residual norm, respectively.