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View of /pkg/TODO

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Revision 935 - (download) (annotate)
Tue Sep 20 10:14:57 2005 UTC (14 years ago) by maechler
File size: 2802 byte(s)
update TODOs
- 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
   - 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!

- 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
  (Kurt is particularly interested in dgCMatrix ones, for pkg 'arules')
  ****> UNFEASIBLE as long cbind is function(..., *) !!!! <*******
    --> follow John's proposition  cbind(x, ...) via Generic cbind2(x,y)?

- consider moving alloc3Darray from ./src/Mutils.c to

-  slot "factors" maybe should move up to "Matrix"


- 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().

BUG: 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


- 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  <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.
  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()
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