/usr/share/freemat/toolbox/array/shiftdim.m is in freemat-data 4.0-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 | % SHIFTDIM SHIFTDIM Shift Array Dimensions Function
%
% Usage
%
% The shiftdim function is used to shift the dimensions of an array.
% The general syntax for the shiftdim function is
%
% y = shiftdim(x,n)
%
% where x is a multidimensional array, and n is an integer. If
% n is a positive integer, then shiftdim circularly shifts the
% dimensions of x to the left, wrapping the dimensions around as
% necessary. If n is a negative integer, then shiftdim shifts
% the dimensions of x to the right, introducing singleton dimensions
% as necessary. In its second form:
%
% [y,n] = shiftdim(x)
%
% the shiftdim function will shift away (to the left) the leading
% singleton dimensions of x until the leading dimension is not
% a singleton dimension (recall that a singleton dimension p is one for
% which size(x,p) == 1).
% Copyright (c) 2007 Samit Basu
% Licensed under the GPL
function [y,n] = shiftdim(x,p)
% Compute the size of x
xsize = size(x);
if (nargin == 1)
% Find the first non-singular dimension of x
p = find(xsize ~= 1,1,'first')-1;
end
if (isempty(p) || (p==0))
% Nothing required
y = x;
n = 0;
elseif (p < 0)
% For right shifting (negative p), we just reshape the array
% and introduce extra singleton dimensions
y = reshape(x,[ones(1,-p),xsize]);
n = p;
else
% Left shifting is modulo the number of dimensions of x
p = rem(p,ndims(x));
% For left shifting, (positive p), we can just reshape the
% array, provided that the leading dimensions are all singletons
% We have to make sure that the reshape call has at least two
% dimensions in the shape argument - the number remaining
% is ndims(x)-p
if (all(xsize(1:p)==1))
xsize = xsize((p+1):end);
if (numel(xsize) < 2), xsize = [xsize,1]; end;
y = reshape(x,xsize);
n = p;
else
% a permutation is in order
y = permute(x,[(p+1):ndims(x),1:p]);
n = p;
end
end
|