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)


10 INPUT "Matrix size: ";size
20 GO SUB 200: REM Identity matrix
30 FOR r=1 TO size
40 FOR c=1 TO size
50 LET s$=CHR$ 13
60 IF c<size THEN LET s$=" "
70 PRINT i(r,c);s$;
80 NEXT c
90 NEXT r
100 STOP 
200 REM Identity matrix size
220 DIM i(size,size)
230 FOR i=1 TO size
240 LET i(i,i)=1
250 NEXT i
260 RETURN