R version 2.9.1 Patched (2009-06-27 r48852)
Copyright (C) 2009 The R Foundation for Statistical Computing
ISBN 3-900051-07-0

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> 
> library("slam")

Attaching package: 'slam'


	The following object(s) are masked from package:base :

	 colMeans,
	 colSums,
	 rowMeans,
	 rowSums 

> set.seed(20090626)
> 
> ###
> 
> x <- sample(0:5, 100, T, prob=c(.8,rep(.04,5)))
> x <- matrix(as.logical(x), nrow = 20,
+      dimnames = list(rows = 1:20, cols = LETTERS[1:5]))
> x
    cols
rows     A     B     C     D     E
  1   TRUE FALSE FALSE FALSE FALSE
  2   TRUE FALSE FALSE FALSE  TRUE
  3  FALSE  TRUE FALSE FALSE FALSE
  4  FALSE FALSE FALSE FALSE  TRUE
  5  FALSE FALSE FALSE FALSE FALSE
  6  FALSE FALSE FALSE  TRUE FALSE
  7  FALSE FALSE FALSE FALSE FALSE
  8  FALSE FALSE FALSE FALSE FALSE
  9  FALSE  TRUE FALSE FALSE FALSE
  10  TRUE FALSE FALSE  TRUE FALSE
  11 FALSE FALSE FALSE FALSE FALSE
  12  TRUE  TRUE FALSE FALSE FALSE
  13 FALSE  TRUE FALSE FALSE FALSE
  14 FALSE FALSE FALSE FALSE FALSE
  15  TRUE  TRUE  TRUE FALSE FALSE
  16 FALSE  TRUE FALSE FALSE FALSE
  17 FALSE FALSE FALSE FALSE FALSE
  18 FALSE FALSE FALSE FALSE FALSE
  19 FALSE FALSE  TRUE FALSE FALSE
  20  TRUE FALSE FALSE FALSE FALSE
> 
> xst <- as.simple_triplet_matrix(x)
> xst

A 20x5 simple triplet matrix.

> 
> identical(rowSums(x), rowSums(xst))
[1] TRUE
> identical(colSums(x), colSums(xst))
[1] TRUE
> identical(rowMeans(x), rowMeans(xst))
[1] TRUE
> identical(colMeans(x), colMeans(xst))
[1] TRUE
> 
> ## NAs
> 
> xna <- x
> n <- prod(dim(x))
> is.na(xna) <- sample(seq_len(n), ceiling(n * .1))
> xna
    cols
rows     A     B     C     D     E
  1   TRUE FALSE FALSE FALSE FALSE
  2   TRUE FALSE FALSE FALSE  TRUE
  3  FALSE    NA FALSE FALSE FALSE
  4  FALSE    NA FALSE FALSE  TRUE
  5  FALSE FALSE FALSE FALSE FALSE
  6  FALSE    NA FALSE    NA FALSE
  7  FALSE FALSE FALSE FALSE FALSE
  8  FALSE FALSE FALSE FALSE FALSE
  9  FALSE  TRUE FALSE FALSE FALSE
  10  TRUE FALSE FALSE  TRUE FALSE
  11    NA FALSE FALSE FALSE FALSE
  12  TRUE    NA FALSE FALSE FALSE
  13 FALSE  TRUE FALSE FALSE FALSE
  14 FALSE FALSE FALSE FALSE    NA
  15  TRUE    NA  TRUE FALSE FALSE
  16 FALSE  TRUE FALSE FALSE FALSE
  17 FALSE FALSE FALSE FALSE FALSE
  18 FALSE FALSE FALSE FALSE FALSE
  19 FALSE FALSE  TRUE FALSE FALSE
  20  TRUE FALSE    NA    NA FALSE
> 
> xnast <- as.simple_triplet_matrix(xna)
> xnast

A 20x5 simple triplet matrix.

> 
> identical(rowSums(xna), rowSums(xnast))
[1] TRUE
> identical(colSums(xna), colSums(xnast))
[1] TRUE
> identical(rowMeans(xna), rowMeans(xnast))
[1] TRUE
> identical(colMeans(xna), colMeans(xnast))
[1] TRUE
> 
> identical(rowSums(xna, na.rm = TRUE), rowSums(xnast, na.rm = TRUE))
[1] TRUE
> identical(colSums(xna, na.rm = TRUE), colSums(xnast, na.rm = TRUE))
[1] TRUE
> identical(rowMeans(xna, na.rm = TRUE), rowMeans(xnast, na.rm = TRUE))
[1] TRUE
> identical(colMeans(xna, na.rm = TRUE), colMeans(xnast, na.rm = TRUE))
[1] TRUE
> 
> ## cross-product
> 
> identical(tcrossprod(x), tcrossprod.simple_triplet_matrix(xst))
[1] TRUE
> identical(tcrossprod(x), tcrossprod.simple_triplet_matrix(xst, x))
[1] TRUE
> 
> x <- matrix(c(1, 0, 0, 2, 1, NA), nrow = 3)
> x
     [,1] [,2]
[1,]    1    2
[2,]    0    1
[3,]    0   NA
> s <- as.simple_triplet_matrix(x)
> 
> identical(tcrossprod(x), tcrossprod.simple_triplet_matrix(s))
[1] TRUE
> identical(tcrossprod(x), tcrossprod.simple_triplet_matrix(s, x))
[1] TRUE
> 
> ###
> 
> 
>