Matrix transposition: Difference between revisions

=={{header|D}}==

<pre>module mxtrans ;

import std.stdio ;

import std.string ;

bool isRectangular(T)(T[][] a){

if(a.length < 1 || a[0].length < 1)

return false ;

for(int i = 1 ; i < a.length; i++)

if(a[i].length != a[i-1].length)

return false ;

return true ;

}

T[][] transpose(T=real)(T[][] a) {

T[][] res ;

if(isRectangular(a)){

res = new T[][](a[0].length, a.length) ;

for(int i = 0 ; i < a.length ; i++)

for(int j = 0 ; j < a[0].length ; j++) {

res[j][i] = a[i][j] ;

}

} else

throw new Exception("Transpose Error") ;

return res ;

}

string toString(T=real)(T[][] a){ // for pretty print

string[] s;

foreach(e ; a)

s ~= format("%8s", e)[1..$-1] ;

return "\n<" ~ join(s,"\n ") ~ ">" ;

}

void main() {

float[][] n, m = [[0.5,0,0,1],[0.0,0.5,0,0],[0.0,0,0.5,-1]] ;

writefln(" m = ", m.toString()) ;

n = m.transpose() ;

writefln(" n (m's transpose) = ", n.toString()) ;

}</pre>