- Sparse matrix methods can now be based on the CHOLMOD package. We will need to migrate from the current code to CHOLMOD-based code using #ifdef USE_CHOLMOD. Some of the things to be done - Move documentation from subdirectories of src to inst/doc - Write utilities to create a cholmod_sparse pointer from a dgCMatrix or lgCMatrix (or zgCMatrix) object without copying and allocating. - Start adding simple S4 methods (rcond, %*%, +, cbind, t). - Report the problem in the Linux ldexp manual page. The second and third calls in the Synopsis should be to ldexpf and ldexpl. - [,] indexing: for sparse "works", but not yet for negative indices! - consider moving alloc3Darray from ./src/Mutils.c to $(RSRC)/src/base/array.c ------- - provide methods for "dspMatrix" and "dppMatrix"! - implement (more) methods for supporting "packed" (symmetric / triangular) matrices; particularly something like pack() and unpack() [to/from our classes from/to "numeric"] --- have already man/unpack.Rd but no method yet! (have some dtr* <-> dtp*) - implement diagonal Matrix class "ddiMatrix" etc using constructor function Diagonal() or Diag(). - rcond() of a singular dpoMatrix gives a LaPack error instead of just 0: MM <- crossprod(M <- Matrix(c(1:4,9:6), 2,4)) ; rcond(MM) ##> Error in rcond(MM) : Lapack routine dpotrf returned error code 4 It's .Call("dpoMatrix_rcond") --> set_rcond() in src/dpoMatrix.c and in src/dppMatrix.c similarly. Done(2005-10-03): The error message is more helpful now. --- - combine the C functions for multiplication by special forms and solution wrt special forms by using a 'right' argument and a 'classed' argument. [done with dgeMatrix_matrix_mm(); not yet for other classes; and for _crossprod()] - add more comprehensive examples / tests for Schur decomposition - arithmetic for sparse matrices: o should return a sparse matrix for at least "+" and "*" , also %%, and "/" and "%/%" at least when the RHS is non-zero a scalar. Challenge: nice implementation (``common non-0''; but Tsparse* is not uniq). --- - Create a Harwell-Boeing version of the matrix mm and the response vector y in inst/external and remove them from the data directory. Modify any examples that use them and modify the Comparisons vignette. - "Math2" , "Math", "Arith": keep triangular and symmetric Matrices when appropriate: particularly desirable for "Math2": round(), signif() - "d" <-> "l" coercion for all "[TCR]" sparse matrices is really trivial: "d" -> "l" : drops the 'x' slot "l" -> "d" : construct an 'x' slot of all '1' We currently have many of these conversions explicitly, e.g. setAs("dsTMatrix", "lsTMatrix", function(from) new("lsTMatrix", i = from@i, j = from@j, uplo = from@uplo, Dim = from@Dim, Dimnames = from@Dimnames)) but I would rather want to automatically construct all these coercion methods at once by a ``method constructor'', i.e., for all "dsparse*" -> "lsparse*" and vice versa. How can one do this {in a documented way} ?