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**696**- (**download**) (**annotate**)*Mon Apr 18 20:03:58 2005 UTC*(14 years, 5 months ago) by*maechler*File size: 2123 byte(s)

sparse "scalar" arithmetic

- Report the problem in the Linux ldexp manual page. The second and third calls in the Synopsis should be to ldexpf and ldexpl. - [,] indexing - group generics: "Arith" (partly done), but also "Compare", "Math" etc; see ?Math and the examples in ?SetGeneric - methods for rbind and cbind where they make sense - consider moving alloc3Darray from ./src/Mutils.c to $(RSRC)/src/base/array.c - data/ : names 'mm' and even more 'y' are ``too short''. If we really want to keep them, don't use "LazyData" (such that one needs data(*) explicitly); But MM would rather want something like ex.mm and ex.y - slot "factors" maybe should move up to "Matrix" ------- We have a (at least one) basic problem : Currently the show() method fail sometime after coercion: e.g. 'sy' show()s wrongly, even though it "str()" fine : (po <- crossprod(Matrix(0:3, 2))) # ok (ge <- as(po, "dgeMatrix")) # ok (sy <- as(po, "dsyMatrix")) # BAD str(sy) # looks fine or example(expand) # -> ex$L and ex$U look bad, however as(ex$L, "dgeMatrix") # `works' {Of course, we don't need a workaround but must understand and solve the problem} --- - 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! - implement diagonal Matrix class "ddiMatrix" etc using constructor function Diagonal() or Diag(). --- - 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: <sparseMatrix> o { <scalar> | <same-dim-sparseMatrix> } should return a sparse matrix for at least "+" and "*" , also %%, and "/" and "%/%" at least when the RHS is non-zero a scalar.

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