in reply to Re^2: Performance problem with Clone Method
in thread Performance problem with Clone Method
PDL(i,j) manipulation:
Look at the get and set functions in PDL::Func.
To note, the difference between column and row operations are the difference between 0 transpose operations and 2 of them. That said, between PDL::Slices and PDL::NiceSlice there are so many ways to skin this cat I'm surprised people worry about the issue of column/row operations in PDL.
See also reorder, dice, range etc. Update:original code example broken.
If you're doing lots of row or column manipulations, perhaps better to keep a 1d piddle of index values and manipulate those.
Look at the get and set functions in PDL::Func.
To note, the difference between column and row operations are the difference between 0 transpose operations and 2 of them. That said, between PDL::Slices and PDL::NiceSlice there are so many ways to skin this cat I'm surprised people worry about the issue of column/row operations in PDL.
#! /usr/bin/perl use PDL; my $M = sequence(10,10); print $M; my $row = $M->slice(':,3'); my $col = $M->slice('4,:'); my $col2 = $M->slice('5,:'); my $deep_col = $col->copy; $col .= $col2; $col2 .= $deep_col; print $M;
See also reorder, dice, range etc. Update:original code example broken.
If you're doing lots of row or column manipulations, perhaps better to keep a 1d piddle of index values and manipulate those.
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Re^4: Performance problem with Clone Method
by BrowserUk (Patriarch) on Jul 27, 2011 at 23:53 UTC | |
by dwm042 (Priest) on Jul 28, 2011 at 03:33 UTC | |
by etj (Deacon) on May 26, 2022 at 14:01 UTC |
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