matlab编程，计算速度能提高100倍。慢的原因，是使用不对！
Loren on the Art of MATLAB
March 1st, 2007
Creating Sparse Finite-Element Matrices in MATLAB

I'm pleased to introduce Tim Davis as this week's guest blogger. Tim is a professor at the University of Florida, and is the author or co-author of many of our sparse matrix functions (lu, chol, much of sparse backslash, ordering methods such as amd and colamd, and other functions such as etree and symbfact). He is also the author of a recent book, Direct Methods for Sparse Linear Systems, published by SIAM, where more details of MATLAB sparse matrices are discussed