function [ x, sx, sy, zx, zy, nx, nv, perm ] = cvx_reduce_size( x, dim, do_reduce )

zx = size( x );

if isempty( dim ),

dim = find( zx ~= 1, 1, 'first' );

if isempty( dim ), dim = 1; end

elseif ~isnumeric( dim ) || numel( dim ) ~= 1 || ~isreal( dim ) || dim <= 0 || isinf(dim) || isnan(dim) || dim ~= floor(dim),

error( 'Dimension argument must be a positive integer.' );

nd = max( dim, length( zx ) );

zx( end + 1 : nd ) = 1;

nx = zx( dim );

zy = zx;

if nargin < 3 || do_reduce, zy( dim ) = 1; end

nl = prod( zy( 1 : dim -1 ) );

nr = prod( zy( dim + 1 : end ) );

nv = nl * nr;

if nl * nx > 1,

perm = [ dim, 1 : dim - 1, dim + 1 : nd ];

x = permute( x, perm );

sx = zx( perm );

sy = zy( perm );

perm = [];

sx = zx;

sy = zy;

x = reshape( x, nx, nv );