Task

Build an   identity matrix   of a size known at run-time.



An identity matrix is a square matrix of size n × n,

where the diagonal elements are all 1s (ones),

and all the other elements are all 0s (zeroes).







I

n


=


[



1


0


0


⋯


0




0


1


0


⋯


0




0


0


1


⋯


0




⋮


⋮


⋮


⋱


⋮




0


0


0


⋯


1



]




{\displaystyle 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}}}





Related tasks

   Spiral matrix
   Zig-zag matrix 
   Ulam_spiral_(for_primes)


' FB 1.05.0 Win64
 
Dim As Integer n
 
Do
  Input "Enter size of matrix "; n
Loop Until n > 0 
 
Dim identity(1 To n, 1 To n) As Integer '' all zero by default
 
' enter 1s in diagonal elements
For i As Integer =  1 To n
  identity(i, i) = 1
Next
 
' print identity matrix if n < 40 
Print
 
If n < 40 Then
  For i As Integer = 1 To n
    For j As Integer = 1 To n
      Print identity(i, j); 
    Next j
    Print
  Next i
Else 
  Print "Matrix is too big to display on 80 column console"
End If
 
Print
Print "Press any key to quit"
Sleep