# how do I generate a spiral matrix which starts from first element

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Hatake nara on 9 Jun 2019
Commented: Arshub on 16 May 2022
there is a command which takes only one arguement as a dimension of a square spiral matrix.But I need a way to generate such a matrix which takes the numbers of rows and columns as inputs and it might not be a square
darova on 9 Jun 2019
I don't understand. How this matrix should looks like? Can you please show some scheme?

PIYUSH AGGARWAL on 9 Jun 2019
Edited: PIYUSH AGGARWAL on 10 Jun 2019
You will have to write your own code for this.
A = zeros(3,6);%You can change this mxn to whatever dims you like, be it square(m=n) or rectangular matrix.
[m,n] = size(A);
%m = no of rows
%n = no of columns
%A = matrix to be filled with spiral values
%This code works fine. I commented an eg also below
top = 1;
bottom = m;
left = 1;
right = n; %To keep track of the four directions
value = 1;%Let us strat from 1
while true
%Top Row First
if left>right
break;
end
for i = left:right
A(top,i) = value;
value = value + 1;
end
top = top + 1;
%Then The RightMost Column
if top>bottom
break;
end
for i = top:bottom
A(i,right) = value;
value = value + 1;
end
right = right - 1;
%Then Bottom Row
if left>right
break;
end
for i = right:-1:left
A(bottom,i) = value;
value = value + 1;
end
bottom = bottom - 1;
%Then The Left Column
if top>bottom
break;
end
for i = bottom:-1:top
A(i,left) = value;
value = value + 1;
end
left = left + 1;
end
A
Arshub on 16 May 2022
@PIYUSH AGGARWAL Please, I hope that you can help me in modifying your code so that I enter an array from me like A= [2 3 5
12 13 14
19 0 4]
and a spiral display is made for it, then I want another code in which I can retrieve my original array. I would be grateful for your help.