Is there any way, in CMUCL, using some implementation-specific construct, to create an "aliased array"? Suppose I create a double-float array of size 10:
(make-array 10 :element-type 'double-float) I know I can take it's address, with #'system:vector-sap. What I want to do is manipulate that address and somehow "invert" vector-sap to create a new double-float array whose first element is (for example) the third element of the original array. I need this because I need to pass matlisp a subset of an array. More specifically, I want to allocate an n by n+1 array, so that I can store half of each of two n by n symmetric arrays in n(n+1) space rather than 2n^2 space. This is a common technique for using BLAS/LAPACK, but to get at it, I need to be able to give a Fortran matlisp routine a way to get at the square n by n matrix that "starts with the second column" of the n by n+1 matrix, and the way the interface is defined, it wants actual arrays, not pointers. If I can somehow create the appropriate array, I don't have to go mucking about in the internals of matlisp's def-fortran-routine and so forth. (Note that I only need this "aliased array" temporarily, and I'd of course turn gc off while I needed it.) Any suggestions or advice are appreciated. If you respond, please cc to rif directly --- I think I'm on both these lists, but I'm not 100% sure. rif
