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[matrix] Annotation of /pkg/TODO
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Annotation of /pkg/TODO

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Revision 1578 - (view) (download)

1 : bates 1236 Check for DimNames propagation in coercion and other operations.
2 : bates 984 ------
3 : bates 1578 - rcond methods for sparseMatrix classes
4 : bates 918
5 : bates 344 - Report the problem in the Linux ldexp manual page. The second and
6 :     third calls in the Synopsis should be to ldexpf and ldexpl.
7 : maechler 472
8 : maechler 868 - [,] indexing: for sparse "works", but not yet for negative indices!
9 : maechler 472
10 : bates 536 - consider moving alloc3Darray from ./src/Mutils.c to
11 : maechler 538 $(RSRC)/src/base/array.c
12 : bates 1578 ------
13 : maechler 634 - provide methods for "dspMatrix" and "dppMatrix"!
14 :    
15 : maechler 538 - implement (more) methods for supporting "packed" (symmetric / triangular)
16 : maechler 634 matrices; particularly something like pack() and unpack() [to/from our
17 :     classes from/to "numeric"] --- have already man/unpack.Rd but no method yet!
18 : maechler 538
19 : maechler 834 (have some dtr* <-> dtp*)
20 :    
21 : bates 1578 -----
22 : bates 645
23 :     - combine the C functions for multiplication by special forms and
24 :     solution wrt special forms by using a 'right' argument and a
25 :     'classed' argument.
26 : maechler 675 [done with dgeMatrix_matrix_mm(); not yet for other classes;
27 :     and for _crossprod()]
28 :    
29 :     - add more comprehensive examples / tests for Schur decomposition
30 : maechler 696
31 :     - arithmetic for sparse matrices:
32 : maechler 935 <sparseMatrix> o <same-dim-sparseMatrix>
33 : maechler 696 should return a sparse matrix for at least "+" and "*" , also %%,
34 :     and "/" and "%/%" at least when the RHS is non-zero a scalar.
35 : maechler 935 Challenge: nice implementation (``common non-0''; but Tsparse* is not uniq).
36 : maechler 696
37 : bates 1578 -----
38 : bates 712
39 : maechler 935 - "Math2" , "Math", "Arith":
40 :     keep triangular and symmetric Matrices when appropriate:
41 :     particularly desirable for "Math2": round(), signif()
42 : maechler 956
43 :     - "d" <-> "l" coercion for all "[TCR]" sparse matrices is really trivial:
44 :     "d" -> "l" : drops the 'x' slot
45 :     "l" -> "d" : construct an 'x' slot of all '1'
46 :     We currently have many of these conversions explicitly, e.g.
47 :     setAs("dsTMatrix", "lsTMatrix",
48 :     function(from) new("lsTMatrix", i = from@i, j = from@j, uplo = from@uplo,
49 :     Dim = from@Dim, Dimnames = from@Dimnames))
50 :     but I would rather want to automatically construct all these coercion
51 :     methods at once by a ``method constructor'', i.e.,
52 :     for all "dsparse*" -> "lsparse*" and vice versa.
53 :     How can one do this {in a documented way} ?
54 : maechler 1087
55 : maechler 1097 - tcrossprod(x, y) : do provide methods for y != NULL
56 :     calling Lapack's DGEMM for "dense"
57 : maechler 1109 [2005-12-xx: done for dgeMatrix at least]
58 :    
59 :     - "ltTmatrix" :
60 :     2) new("ltTMatrix", diag = "U", Dim = c(2:2, 2:2)) shows lack of ltTM*_validate
61 : maechler 1201
62 :     - BUGlet: Shouldn't lose factorization here:
63 :     h6 <- Hilbert(6); chol(h6) ; str(h6) # has factor
64 :     str(H6 <- as(h6, "dspMatrix")) # has lost factor
65 :     ## and the same in a similar situation involving "dpo", "dpp"
66 : maechler 1226
67 :     - "Compare" for dgC & dgT --- want to be able to do M[M > 10] etc
68 : maechler 1245
69 :     - Things like M[upper.tri(M)] are not really most useful for sparse
70 :     matrices. --> provide generic functions
71 :     upperTriMatrix(), lowerTriMatrix() both with argument 'diag = TRUE'
72 :     (which can be set to FALSE of course) which are used to extract a
73 :     triangle from an arbitrary sparse matrix and return a "dtCMatrix".
74 :    
75 :     - Factorizations: LU [ -> solve() ] and Schur() for *sparse* Matrices.
76 :     ----------------- LU-sparse is the purpose of all of ./src/UMFPACK/
77 :     --> ./inst/doc/UFsparse/*
78 : maechler 1315 Note that UMFPACK is a bit slow compared to TAUCS etc, according to
79 :     Gould et al.(2005)
80 : maechler 1245 And then, possibly eigen(), svd(), qr(), ... for sparse
81 :     {probably base some on the fast chol() of CHOLMOD}.
82 : maechler 1315 ./man/lu.Rd notes that lu() is not yet available for sparse
83 : maechler 1253
84 :     2006-04-15 : now with 'CSparse' { src/cs.c }, have at least solve( <dtC*> )
85 :    
86 : maechler 1290 - nicer pedigree examples and tests
87 : maechler 1349
88 :     - band(), triu(), tril() for *all*, not just sparse matrices
89 : maechler 1575
90 :     - is.na() method for all our matrices [ ==> which(*, arr.ind=TRUE) might work ]

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