Gives helpful information on the usage and purpose of a function. Ex:
help('LU')would print out:
Usage: LU(<matrix>) Computes an LU factorization of a general M-by-N matrix using partial pivoting with row interchanges. Factorization has the form A = P*L*U.On exit, the input matrix is comprised of the factors L and U from the factorization A = P*L*U. Returns an integer vector. The row i of A was interchanged with row IPIV(i). Ex: LU([1,2;3,4]) See: http://www.osl.iu.edu/research/mtl/doc/getrfLapackMatrixVectorInt.html
The ``Usage'' line shows how to invoke the function and the sort of arguments it can take. In this case, the LU function takes one argument, and it must be a matrix.