lower.tri {spam} | R Documentation |
Lower and Upper Triangular Part of a Sparse Matrix
Description
Returns the lower or upper triangular structure or entries of a sparse matrix.
Usage
lower.tri(x, diag = FALSE)
upper.tri(x, diag = FALSE)
Arguments
x |
a sparse matrix of class |
diag |
logical. Should the diagonal be included? |
Details
Often not only the structure of the matrix is required but the
entries as well. For compatibility, the default is only a structure
consisting of ones (representing TRUE
s). Setting the flag
getOption( "spam.trivalues")
to TRUE
,
the function returns the actual
values.
See Also
spam.options
and diag
Examples
smat <- spam( c( 1,2,0,3,0,0,0,4,5),3)
upper.tri( smat)
upper.tri( smat, diag=TRUE)
options(spam.trivalues=TRUE)
upper.tri( smat)
[Package spam version 2.10-0 Index]