How to shift the columns of a PDL matrix

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I have a PDL that is 8 columns by 120 rows.

I want to simply SHIFT all the columns to the right by 1 and insert a column of 0's for the first column. I would prefer to DROP the last column so I don't change the dimensions.

I think I can do it by slicing and gluing into a new PDL, but was wondering if there was any faster function that would hel me do it. I would prefer to use "inplace" if possible to minimize memory.

Also, I am aware of the SHIFTRIGHT function, but that doesn't seem to be doing the job. I believe that is a binary shift function.

Thanks!

Comment on How to shift the columns of a PDL matrix

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Re: How to shift the columns of a PDL matrix by lin0 (Curate) on Jul 03, 2007 at 22:35 UTC
Hi Anonymous Monk, you could use something like: `$pdl = append(zeroes(1,$pdl->getdim(1)), $pdl(0:-2,:));` [download] where $pdl is your 8 columns by 120 rows piddle Note: I am assuming you are using PDL::NiceSlice Cheers, lin0	[reply] [d/l]
Re^2: How to shift the columns of a PDL matrix by Anonymous Monk on Nov 04, 2016 at 09:42 UTC
since you don't want to grow your matrix, it is even simpler to use rotate to shift your columns and then insert your new data. `$pdl=$pdl->rotate(1); $pdl(0,).=$new_data # your vector.` [download]	[reply] [d/l]

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