I use matlab/fortran to deal with some large eigenvalue problem (FEM type).For example, I use spalloc and eigs to declare and solve the problem in Matlab,could anyone give some advice on how can I do it in Fortran? any routine like spalloc/eigs?
Programming with Fortran, large eigen value problem
fortran
If your matrices are dense, then LAPACK is the way to go.  If they are sparse, then ARPACK is often better suited.  There is no standard equivalent of spalloc: LAPACK only supports dense matrices and ARPACK lets you store the data however you like, you just compute the action $A x$ for it.You may also want to check out this stackoverflow question.