A-M baby

Task/Identity-matrix/0DESCRIPTION

@@ -0,0 +1,9 @@
+Build an [[wp:identity matrix|identity matrix]] of a size known at runtime. An identity matrix is a square matrix, of size ''n'' × ''n'', where the diagonal elements are all 1s, and the other elements are all 0s.
+
+<math>I_n = \begin{bmatrix}
+  1      & 0      & 0      & \cdots & 0      \\
+  0      & 1      & 0      & \cdots & 0      \\
+  0      & 0      & 1      & \cdots & 0      \\
+  \vdots & \vdots & \vdots & \ddots & \vdots \\
+  0      & 0      & 0      & \cdots & 1      \\
+\end{bmatrix}</math>

Task/Identity-matrix/1META.yaml

@@ -0,0 +1,3 @@
+---
+category:
+- Matrices

Task/Identity-matrix/APL/identity-matrix-1.apl

@@ -0,0 +1,4 @@
+    ∘.=/⍳¨3 3
+1 0 0
+0 1 0
+0 0 1

Task/Identity-matrix/APL/identity-matrix-2.apl

@@ -0,0 +1,7 @@
+    ID←{∘.=/⍳¨ ⍵ ⍵}
+    ID 5
+1 0 0 0 0
+0 1 0 0 0
+0 0 1 0 0
+0 0 0 1 0
+0 0 0 0 1

Task/Identity-matrix/APL/identity-matrix-3.apl

@@ -0,0 +1 @@
+    ID←{⍵ ⍵ ρ 1, ⍵ρ0}

Task/Identity-matrix/AWK/identity-matrix.awk

@@ -0,0 +1,17 @@
+# syntax: GAWK -f IDENTITY_MATRIX.AWK size
+BEGIN {
+    size = ARGV[1]
+    if (size !~ /^[0-9]+$/) {
+      print("size invalid or missing from command line")
+      exit(1)
+    }
+    for (i=1; i<=size; i++) {
+      for (j=1; j<=size; j++) {
+        x = (i == j) ? 1 : 0
+        printf("%2d",x) # print
+        arr[i,j] = x # build
+      }
+      printf("\n")
+    }
+    exit(0)
+}

Task/Identity-matrix/Ada/identity-matrix-1.ada

@@ -0,0 +1,4 @@
+--  As prototyped in the Generic_Real_Arrays specification:
+--  function Unit_Matrix (Order : Positive; First_1, First_2 : Integer := 1) return Real_Matrix;
+-- For the task:
+mat : Real_Matrix := Unit_Matrix(5);

Task/Identity-matrix/Ada/identity-matrix-2.ada

@@ -0,0 +1,4 @@
+type Matrix is array(Positive Range <>, Positive Range <>) of Integer;
+mat : Matrix(1..5,1..5) := (others => (others => 0));
+--  then after the declarative section:
+for i in mat'Range(1) loop mat(i,i) := 1; end loop;

Task/Identity-matrix/BBC-BASIC/identity-matrix.bbc

@@ -0,0 +1,17 @@
+      INPUT "Enter size of matrix: " size%
+      PROCidentitymatrix(size%, im())
+      FOR r% = 0 TO size%-1
+        FOR c% = 0 TO size%-1
+          PRINT im(r%, c%),;
+        NEXT
+        PRINT
+      NEXT r%
+      END
+
+      DEF PROCidentitymatrix(s%, RETURN m())
+      LOCAL i%
+      DIM m(s%-1, s%-1)
+      FOR i% = 0 TO s%-1
+        m(i%,i%) = 1
+      NEXT
+      ENDPROC

Task/Identity-matrix/Burlesque/identity-matrix-1.blq

@@ -0,0 +1,7 @@
+blsq ) 6 -.^^0\/r@\/'0\/.*'1+]\/{\/{rt}\/E!XX}x/+]m[sp
+1 0 0 0 0 0
+0 1 0 0 0 0
+0 0 1 0 0 0
+0 0 0 1 0 0
+0 0 0 0 1 0
+0 0 0 0 0 1

Task/Identity-matrix/Burlesque/identity-matrix-2.blq

@@ -0,0 +1 @@
+6hd0bx#a.*\[#a.*0#a?dr@{(D!)\/1\/^^bx\/[+}m[e!

Task/Identity-matrix/C-sharp/identity-matrix.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Linq;
+
+namespace IdentityMatrix
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            if (args.Length != 1)
+            {
+                Console.WriteLine("Requires exactly one argument");
+                return;
+            }
+            int n;
+            if (!int.TryParse(args[0], out n))
+            {
+                Console.WriteLine("Requires integer parameter");
+                return;
+            }
+
+            var identity =
+                Enumerable.Range(0, n).Select(i => Enumerable.Repeat(0, n).Select((z,j) => j == i ? 1 : 0).ToList()).ToList();
+            foreach (var row in identity)
+            {
+                foreach (var elem in row)
+                {
+                    Console.Write(" " + elem);
+                }
+                Console.WriteLine();
+            }
+            Console.ReadKey();
+        }
+    }
+}

Task/Identity-matrix/C/identity-matrix.c

@@ -0,0 +1,38 @@
+#include <stdlib.h>
+#include <stdio.h>
+int main(int argc, char** argv) {
+   if (argc < 2) {
+      printf("usage: identitymatrix <number of rows>\n");
+      exit(EXIT_FAILURE);
+   }
+   signed int rowsize = atoi(argv[1]);
+   if (rowsize < 0) {
+      printf("Dimensions of matrix cannot be negative\n");
+      exit(EXIT_FAILURE);
+   }
+   volatile int numElements = rowsize * rowsize;
+   if (numElements < rowsize) {
+      printf("Squaring %d caused result to overflow to %d.\n", rowsize, numElements);
+      abort();
+   }
+   int** matrix = calloc(numElements, sizeof(int*));
+   if (!matrix) {
+      printf("Failed to allocate %d elements of %d bytes each\n", numElements, sizeof(int*));
+      abort();
+   }
+   for (unsigned int row = 0;row < rowsize;row++) {
+      matrix[row] = calloc(numElements, sizeof(int));
+      if (!matrix[row]) {
+         printf("Failed to allocate %d elements of %d bytes each\n", numElements, sizeof(int));
+         abort();
+      }
+      matrix[row][row] = 1;
+   }
+   printf("Matrix is: \n");
+   for (unsigned int row = 0;row < rowsize;row++) {
+      for (unsigned int column = 0;column < rowsize;column++) {
+         printf("%d ", matrix[row][column]);
+      }
+      printf("\n");
+   }
+}

Task/Identity-matrix/Clojure/identity-matrix-1.clj

@@ -0,0 +1 @@
+ '( (0 1) (2 3) )

Task/Identity-matrix/Clojure/identity-matrix-2.clj

@@ -0,0 +1,6 @@
+(defn identity-matrix [n]
+  (let [row (conj (repeat (dec n) 0) 1)]
+    (vec
+      (for [i (range 1 (inc n))]
+        (vec
+          (reduce conj (drop i row ) (take i row)))))))

Task/Identity-matrix/Clojure/identity-matrix-3.clj

@@ -0,0 +1,2 @@
+=> (identity-matrix 5)
+[[1 0 0 0 0] [0 1 0 0 0] [0 0 1 0 0] [0 0 0 1 0] [0 0 0 0 1]]

Task/Identity-matrix/Clojure/identity-matrix-4.clj

@@ -0,0 +1,4 @@
+(defn identity-matrix [n]
+  (take n
+    (partition n (dec n)
+                         (cycle (conj (repeat (dec n) 0) 1)))))

Task/Identity-matrix/Common-Lisp/identity-matrix.lisp

@@ -0,0 +1,4 @@
+(defun make-identity-matrix (n)
+  (let ((array (make-array (list n n) :initial-element 0)))
+    (loop for i below n do (setf (aref array i i) 1))
+    array))

Task/Identity-matrix/D/identity-matrix.d

@@ -0,0 +1,30 @@
+import std.traits;
+
+T[][] matId(T)(in size_t n) pure nothrow if (isAssignable!(T, T)) {
+    auto Id = new T[][](n, n);
+
+    foreach (r, row; Id) {
+        static if (__traits(compiles, {row[] = 0;})) {
+            row[] = 0; // vector op doesn't work with T = BigInt
+            row[r] = 1;
+        } else {
+            foreach (c; 0 .. n)
+                row[c] = (c == r) ? 1 : 0;
+        }
+    }
+
+    return Id;
+}
+
+void main() {
+    import std.stdio, std.bigint;
+    enum form = "[%([%(%s, %)],\n %)]]";
+
+    immutable id1 = matId!real(5);
+    writefln(form ~ "\n", id1);
+
+    immutable id2 = matId!BigInt(3);
+    writefln(form ~ "\n", id2);
+
+    // auto id3 = matId!(const int)(2); // cant't compile
+}

Task/Identity-matrix/Euler-Math-Toolbox/identity-matrix-1.euler

@@ -0,0 +1,7 @@
+function IdentityMatrix(n)
+  $  X:=zeros(n,n);
+  $  for i=1 to n
+  $    X[i,i]:=1;
+  $  end;
+  $  return X;
+  $endfunction

Task/Identity-matrix/Euler-Math-Toolbox/identity-matrix-2.euler

@@ -0,0 +1,3 @@
+>function IdentityMatrix (n:index)
+$  return setdiag(zeros(n,n),0,1);
+$endfunction

Task/Identity-matrix/Euler-Math-Toolbox/identity-matrix-3.euler

@@ -0,0 +1 @@
+>id(5)

Task/Identity-matrix/Fortran/identity-matrix.f

@@ -0,0 +1,23 @@
+program identitymatrix
+
+  real, dimension(:, :), allocatable :: I
+  character(len=8) :: fmt
+  integer :: ms, j
+
+  ms = 10   ! the desired size
+
+  allocate(I(ms,ms))
+  I = 0                           ! Initialize the array.
+  forall(j = 1:ms) I(j,j) = 1     ! Set the diagonal.
+
+  ! I is the identity matrix, let's show it:
+
+  write (fmt, '(A,I2,A)') '(', ms, 'F6.2)'
+  ! if you consider to have used the (row, col) convention,
+  ! the following will print the transposed matrix (col, row)
+  ! but I' = I, so it's not important here
+  write (*, fmt) I(:,:)
+
+  deallocate(I)
+
+end program identitymatrix

Task/Identity-matrix/Go/identity-matrix-1.go

@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Println(I(3))
+}
+
+func I(n int) [][]float64 {
+    m := make([][]float64, n)
+    a := make([]float64, n*n)
+    for i := 0; i < n; i++ {
+        a[i] = 1
+        m[i] = a[:n]
+        a = a[n:]
+    }
+    return m
+}

Task/Identity-matrix/Go/identity-matrix-2.go

@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+type matrix []float64
+
+func main() {
+    fmt.Println(I(3))
+}
+
+func I(n int) matrix {
+    m := make(matrix, n*n)
+    n++
+    for i := 0; i < len(m); i += n {
+        m[i] = 1
+    }
+    return m
+}

Task/Identity-matrix/Go/identity-matrix-3.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+    "fmt"
+
+    mat "github.com/skelterjohn/go.matrix"
+)
+
+func main() {
+    fmt.Println(mat.Eye(3))
+}

Task/Identity-matrix/Groovy/identity-matrix-1.groovy

@@ -0,0 +1,3 @@
+def makeIdentityMatrix = { n ->
+    (0..<n).collect { i -> (0..<n).collect { j -> (i == j) ? 1 : 0 } }
+}

Task/Identity-matrix/Groovy/identity-matrix-2.groovy

@@ -0,0 +1,5 @@
+(2..6).each { order ->
+    def iMatrix = makeIdentityMatrix(order)
+    iMatrix.each { println it }
+    println()
+}

Task/Identity-matrix/Haskell/identity-matrix-1.hs

@@ -0,0 +1 @@
+matI n = [ [fromEnum $ i == j | i <- [1..n]] | j <- [1..n]]

Task/Identity-matrix/Haskell/identity-matrix-2.hs

@@ -0,0 +1,2 @@
+showMat :: [[Int]] -> String
+showMat = unlines . map (unwords . map show)

Task/Identity-matrix/Haskell/identity-matrix-3.hs

@@ -0,0 +1,10 @@
+*Main> putStr $ showMat $ matId 9
+1 0 0 0 0 0 0 0 0
+0 1 0 0 0 0 0 0 0
+0 0 1 0 0 0 0 0 0
+0 0 0 1 0 0 0 0 0
+0 0 0 0 1 0 0 0 0
+0 0 0 0 0 1 0 0 0
+0 0 0 0 0 0 1 0 0
+0 0 0 0 0 0 0 1 0
+0 0 0 0 0 0 0 0 1

Task/Identity-matrix/J/identity-matrix.j

@@ -0,0 +1,12 @@
+   = i. 4          NB. create an Identity matrix of size 4
+1 0 0 0
+0 1 0 0
+0 0 1 0
+0 0 0 1
+   makeI=: =@i.    NB. define as a verb with a user-defined name
+   makeI 5         NB. create an Identity matrix of size 5
+1 0 0 0 0
+0 1 0 0 0
+0 0 1 0 0
+0 0 0 1 0
+0 0 0 0 1

Task/Identity-matrix/Java/identity-matrix.java

@@ -0,0 +1,30 @@
+public class IdentityMatrix {
+
+	public static int[][] matrix(int n){
+		int[][] array = new int[n][n];
+		
+		for(int row=0; row<n; row++){
+			for(int col=0; col<n; col++){
+				if(row == col){
+					array[row][col] = 1;
+				}
+				else{
+					array[row][col] = 0;
+				}
+			}
+		}
+		return array;
+	}
+	public static void printMatrix(int[][] array){
+		for(int row=0; row<array.length; row++){
+			for(int col=0; col<array[row].length; col++){
+				System.out.print(array[row][col] + "\t");
+			}
+			System.out.println();
+		}
+	}
+	public static void main (String []args){
+		printMatrix(matrix(5));
+	}
+}
+By Sani Yusuf @saniyusuf.

Task/Identity-matrix/LSL/identity-matrix.lsl

@@ -0,0 +1,19 @@
+default {
+	state_entry() {
+		llListen(PUBLIC_CHANNEL, "", llGetOwner(), "");
+		llOwnerSay("Please Enter a Dimension for an Identity Matrix.");
+	}
+	listen(integer iChannel, string sName, key kId, string sMessage) {
+		llOwnerSay("You entered "+sMessage+".");
+		list lMatrix = [];
+		integer x = 0;
+		integer n = (integer)sMessage;
+		for(x=0 ; x<n*n ; x++) {
+			lMatrix += [(integer)(((x+1)%(n+1))==1)];
+		}
+		//llOwnerSay("["+llList2CSV(lMatrix)+"]");
+		for(x=0 ; x<n ; x++) {
+			llOwnerSay("["+llList2CSV(llList2ListStrided(lMatrix, x*n, (x+1)*n-1, 1))+"]");
+		}
+	}
+}

Task/Identity-matrix/Lang5/identity-matrix.lang5

@@ -0,0 +1,8 @@
+: identity-matrix
+    dup iota 'A set
+
+    : i.(*) A in ;
+    [1] swap append reverse A swap reshape 'i. apply
+    ;
+
+5 identity-matrix .

Task/Identity-matrix/Lua/identity-matrix.lua

@@ -0,0 +1,18 @@
+function identity_matrix (size)
+        local m = {}
+        for i = 1, size do
+                m[i] = {}
+                for j = 1, size do
+                        m[i][j] = i == j and 1 or 0
+                end
+        end
+        return m
+end
+
+function print_matrix (m)
+        for i = 1, #m do
+                print(table.concat(m[i], " "))
+        end
+end
+
+print_matrix(identity_matrix(5))

Task/Identity-matrix/Maple/identity-matrix-1.maple

@@ -0,0 +1,8 @@
+> LinearAlgebra:-IdentityMatrix( 4 );
+                           [1    0    0    0]
+                           [                ]
+                           [0    1    0    0]
+                           [                ]
+                           [0    0    1    0]
+                           [                ]
+                           [0    0    0    1]

Task/Identity-matrix/Maple/identity-matrix-2.maple

@@ -0,0 +1,8 @@
+> Matrix( 4, shape = scalar[1], datatype = float[4] );
+                         [1.    0.    0.    0.]
+                         [                    ]
+                         [0.    1.    0.    0.]
+                         [                    ]
+                         [0.    0.    1.    0.]
+                         [                    ]
+                         [0.    0.    0.    1.]

Task/Identity-matrix/Maple/identity-matrix-3.maple

@@ -0,0 +1,8 @@
+> Matrix( 4, shape = identity, datatype = integer[ 2 ] );
+                           [1    0    0    0]
+                           [                ]
+                           [0    1    0    0]
+                           [                ]
+                           [0    0    1    0]
+                           [                ]
+                           [0    0    0    1]

Task/Identity-matrix/Mathematica/identity-matrix.mathematica

@@ -0,0 +1 @@
+IdentityMatrix[4]

Task/Identity-matrix/Maxima/identity-matrix.maxima

@@ -0,0 +1,5 @@
+ident(4);
+/* matrix([1, 0, 0, 0],
+          [0, 1, 0, 0],
+          [0, 0, 1, 0],
+          [0, 0, 0, 1]) */

Task/Identity-matrix/PHP/identity-matrix.php

@@ -0,0 +1,25 @@
+function createMatrix($size)
+{
+    $result = array();
+
+    for ($i = 0; $i < $size; $i++) {
+        $row      = array_fill(0, $size, 0);
+        $row[$i]  = 1;
+        $result[] = $row;
+    }
+
+    return $result;
+}
+
+function printMatrix(array $matrix)
+{
+    foreach ($matrix as $row) {
+        foreach ($row as $column) {
+            echo $column . " ";
+        }
+        echo PHP_EOL;
+    }
+    echo PHP_EOL;
+}
+
+printMatrix(createMatrix(5));

Task/Identity-matrix/Perl/identity-matrix.pl

@@ -0,0 +1,18 @@
+sub identity_matrix {
+    my $n = shift;
+    map {
+      my $i = $_;
+      [ map { ($_ == $i) - 0 } 1 .. $n ]
+    } 1 .. $n;
+}
+
+@ARGV = (4, 5, 6) unless @ARGV;
+
+for (@ARGV) {
+  my @id = identity_matrix $_;
+  print "$_:\n";
+  for (my $i=0; $i<@id; ++$i) {
+    print join ' ', @{$id[$i]}, "\n";
+  }
+  print "\n";
+}

Task/Identity-matrix/PicoLisp/identity-matrix-1.l

@@ -0,0 +1,5 @@
+(de identity (Size)
+   (let L (need Size (1) 0)
+      (make
+         (do Size
+            (link (copy (rot L))) ) ) ) )

Task/Identity-matrix/PicoLisp/identity-matrix-2.l

@@ -0,0 +1,9 @@
+: (identity 3)
+-> ((1 0 0) (0 1 0) (0 0 1))
+
+: (mapc println (identity 5))
+(1 0 0 0 0)
+(0 1 0 0 0)
+(0 0 1 0 0)
+(0 0 0 1 0)
+(0 0 0 0 1)

Task/Identity-matrix/Python/identity-matrix-1.py

@@ -0,0 +1,10 @@
+def identity(size):
+    matrix = [[0] * size] * size
+
+    for i in range(size):
+        matrix[i][i] = 1
+
+    for rows in matrix:
+        for elements in rows:
+            print elements,
+        print ""

Task/Identity-matrix/Python/identity-matrix-2.py

@@ -0,0 +1 @@
+np.mat(np.eye(size))

Task/Identity-matrix/R/identity-matrix-1.r

@@ -0,0 +1 @@
+diag(3)

Task/Identity-matrix/R/identity-matrix-2.r

@@ -0,0 +1,4 @@
+     [,1] [,2] [,3]
+[1,]    1    0    0
+[2,]    0    1    0
+[3,]    0    0    1

Task/Identity-matrix/REXX/identity-matrix-1.rexx

@@ -0,0 +1,28 @@
+/*REXX program to  create  and  display  an identity matrix.            */
+call identity_matrix 4                 /*build and display a 4x4 matrix.*/
+call identity_matrix 5                 /*build and display a 5x5 matrix.*/
+exit                                   /*stick a fork in it, we're done.*/
+/*─────────────────────────────────────IDENTITY_MATRIX subroutine───────*/
+identity_matrix:  procedure;  parse arg n;  $=
+
+    do r=1 for n                       /*build indentity matrix, by row,*/
+          do c=1 for n                 /*                    and by cow.*/
+          $=$ (r==c)                   /*append zero or one (if on diag)*/
+          end    /*c*/
+    end          /*r*/
+
+call showMatrix 'identity matrix of size' n,$,n
+return
+/*─────────────────────────────────────TELL subroutine───&find the order*/
+showMatrix: procedure; parse arg hdr,x,order,sep;  if sep=='' then sep='═'
+    width=2          /*width of field to be used to display the elements*/
+decPlaces=1          /*# decimal places to the right of decimal point.  */
+say;  say center(hdr,max(length(hdr)+6,(width+1)*words(x)%order),sep); say
+#=0
+           do row=1      for order;   aLine=
+                do col=1 for order;   #=#+1
+                aLine=aLine  right(format(word(x,#),,decPlaces)/1, width)
+                end   /*col*/          /*dividing by 1 normalizes the #.*/
+           say aLine
+           end        /*row*/
+return

Task/Identity-matrix/REXX/identity-matrix-2.rexx

@@ -0,0 +1,16 @@
+/* REXX ***************************************************************
+* show identity matrix of size n
+* I consider m.i.j to represent the matrix (not needed for showing)
+* 06.07.2012 Walter Pachl
+**********************************************************************/
+Parse Arg n
+Say 'Identity Matrix of size' n '(m.i.j IS the Matrix)'
+m.=0
+Do i=1 To n
+  ol=''
+  Do j=1 To n
+    m.i.j=(i=j)
+    ol=ol''format(m.i.j,2) /* or ol=ol (i=j)                         */
+    End
+  Say ol
+  End

Task/Identity-matrix/REXX/identity-matrix-3.rexx

@@ -0,0 +1,3 @@
+m.=0
+m.0=1000 /* the matrix' size */
+m.4.17.333='Walter'

Task/Identity-matrix/Racket/identity-matrix.rkt

@@ -0,0 +1,3 @@
+#lang racket
+(require math)
+(identity-matrix 5)

Task/Identity-matrix/Ruby/identity-matrix.rb

@@ -0,0 +1,7 @@
+def identity(size)
+  size.times.map { |i| size.times.map { |j| i == j ? 1 : 0 } }
+end
+
+[4,5,6].each do |size|
+  puts size, identity(size.to_i).map {|r| r.to_s}, ""
+end

Task/Identity-matrix/Scala/identity-matrix.scala

@@ -0,0 +1,4 @@
+def identityMatrix(n:Int)=Array.tabulate(n,n)((x,y) => if(x==y) 1 else 0)
+def printMatrix[T](m:Array[Array[T]])=m map (_.mkString("[", ", ", "]")) mkString "\n"
+
+printMatrix(identityMatrix(5))

Task/Identity-matrix/Scheme/identity-matrix-1.ss

@@ -0,0 +1,15 @@
+(define (identity n)
+  (letrec
+      ((uvec
+	(lambda (m i acc)
+	  (if (= i n)
+	      acc
+	      (uvec m (+ i 1)
+		    (cons (if (= i m) 1 0) acc)))))
+       (idgen
+	(lambda (i acc)
+	  (if (= i n)
+	      acc
+	      (idgen (+ i 1)
+		     (cons (uvec i 0 '()) acc))))))
+       (idgen 0 '())))

Task/Identity-matrix/Scheme/identity-matrix-2.ss

@@ -0,0 +1 @@
+(display (identity 4))

Task/Identity-matrix/Tcl/identity-matrix-1.tcl

@@ -0,0 +1,7 @@
+proc I {rank {zero 0.0} {one 1.0}} {
+    set m [lrepeat $rank [lrepeat $rank $zero]]
+    for {set i 0} {$i < $rank} {incr i} {
+	lset m $i $i $one
+    }
+    return $m
+}

Task/Identity-matrix/Tcl/identity-matrix-2.tcl

@@ -0,0 +1,13 @@
+package require struct::matrix
+
+proc I {rank {zero 0.0} {one 1.0}} {
+    set m [struct::matrix]
+    $m add columns $rank
+    $m add rows $rank
+    for {set i 0} {$i < $rank} {incr i} {
+	for {set j 0} {$j < $rank} {incr j} {
+	    $m set cell $i $j [expr {$i==$j ? $one : $zero}]
+	}
+    }
+    return $m
+}

Task/Identity-matrix/Tcl/identity-matrix-3.tcl

@@ -0,0 +1,2 @@
+set m [I 5 0 1]    ;# Integer 0/1 for clarity of presentation
+puts [$m format 2string]