Aliases: forceSymmetric forceSymmetric,CsparseMatrix,character-method forceSymmetric,CsparseMatrix,missing-method forceSymmetric,RsparseMatrix,character-method forceSymmetric,RsparseMatrix,missing-method forceSymmetric,TsparseMatrix,character-method forceSymmetric,TsparseMatrix,missing-method forceSymmetric,diagonalMatrix,character-method forceSymmetric,diagonalMatrix,missing-method forceSymmetric,indMatrix,character-method forceSymmetric,indMatrix,missing-method forceSymmetric,matrix,character-method forceSymmetric,matrix,missing-method forceSymmetric,packedMatrix,character-method forceSymmetric,packedMatrix,missing-method forceSymmetric,unpackedMatrix,character-method forceSymmetric,unpackedMatrix,missing-method
Keywords: array
### ** Examples ## Hilbert matrix i <- 1:6 h6 <- 1/outer(i - 1L, i, "+") sd <- sqrt(diag(h6)) hh <- t(h6/sd)/sd # theoretically symmetric isSymmetric(hh, tol=0) # FALSE; hence
[1] FALSE
try( as(hh, "symmetricMatrix") ) # fails, but this works fine:
6 x 6 Matrix of class "dsyMatrix"
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1.0000000 0.8660254 0.7453560 0.6614378 0.6000000 0.5527708
[2,] 0.8660254 1.0000000 0.9682458 0.9165151 0.8660254 0.8206518
[3,] 0.7453560 0.9682458 1.0000000 0.9860133 0.9583148 0.9270248
[4,] 0.6614378 0.9165151 0.9860133 1.0000000 0.9921567 0.9749960
[5,] 0.6000000 0.8660254 0.9583148 0.9921567 1.0000000 0.9949874
[6,] 0.5527708 0.8206518 0.9270248 0.9749960 0.9949874 1.0000000
H6 <- forceSymmetric(hh) ## result can be pretty surprising: (M <- Matrix(1:36, 6))
6 x 6 Matrix of class "dgeMatrix"
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 7 13 19 25 31
[2,] 2 8 14 20 26 32
[3,] 3 9 15 21 27 33
[4,] 4 10 16 22 28 34
[5,] 5 11 17 23 29 35
[6,] 6 12 18 24 30 36
forceSymmetric(M) # symmetric, hence very different in lower triangle
6 x 6 Matrix of class "dsyMatrix"
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 7 13 19 25 31
[2,] 7 8 14 20 26 32
[3,] 13 14 15 21 27 33
[4,] 19 20 21 22 28 34
[5,] 25 26 27 28 29 35
[6,] 31 32 33 34 35 36
(tm <- tril(M))
6 x 6 Matrix of class "dtrMatrix"
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 . . . . .
[2,] 2 8 . . . .
[3,] 3 9 15 . . .
[4,] 4 10 16 22 . .
[5,] 5 11 17 23 29 .
[6,] 6 12 18 24 30 36
forceSymmetric(tm)
6 x 6 Matrix of class "dsyMatrix"
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 2 3 4 5 6
[2,] 2 8 9 10 11 12
[3,] 3 9 15 16 17 18
[4,] 4 10 16 22 23 24
[5,] 5 11 17 23 29 30
[6,] 6 12 18 24 30 36