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Asked by Noru
on 21 Mar 2013

I have some trouble when creating matrix 4x2 with rules like below. the first column are integer and the other column are random number. I already create the syntax below.

for ii = 1:8, nilai = mod(ii,2); if nilai == 0 x(ii) = 0.95 + (1.05-0.95)*x(ii); elseif nilai ~= 0 x(ii) = round(3 + (30-3)*x(ii)); elseif nilai ~= 0 x(ii) = 0.01 + (0.055-0.01)*x(ii); else x(ii) = 1.0 + (1.15-1.0)*x(ii); end end x = reshape(x,4,2)';

but the result are

??? Error using ==> reshape To RESHAPE the number of elements must not change.

anyone can help me with this problem..? any solutions are very welcome..

thank you.

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Answer by the cyclist
on 21 Mar 2013

Accepted answer

What is the shape of x before you start? It seems that it is probably not an 8-element array, so the reshape fails.

Noru
on 21 Mar 2013

the shape of x that i want to create is an 8 element array, then i want to reshape those 8 element array become 4x2 matrix with integer number in the first column, but i have some problem when define loop (for)

the cyclist
on 21 Mar 2013

You did not answer my question. What is the shape of x BEFORE this loop?

As you can see from Image Analyst's answer, there is no problem if x is 1x8 before your loop.

Answer by Image Analyst
on 21 Mar 2013

I got a different error message due to x not being predefined and your new x(ii) depends on your old x(ii). When I predefined x, it ran with no errors:

x = zeros(1, 8); for ii = 1:8 nilai = mod(ii,2); if nilai == 0 x(ii) = 0.95 + (1.05-0.95)*x(ii); elseif nilai ~= 0 x(ii) = round(3 + (30-3)*x(ii)); elseif nilai ~= 0 x(ii) = 0.01 + (0.055-0.01)*x(ii); else x(ii) = 1.0 + (1.15-1.0)*x(ii); end end x = reshape(x,4,2)'

In the command window:

x = 3 0.95 3 0.95 3 0.95 3 0.95

Noru
on 21 Mar 2013

now i already done create a matrix like you do, but i want to make the value of the 3rd column like 2nd and 4th(non integer number) like below

x = 8 0.67 0.32 0.76 14 0.49 0.21 0.53

do you have any solution..?

Image Analyst
on 21 Mar 2013

% make the value of the 3rd column like 2nd x(:,3) = x(:,2); % make the value of the 3rd column like 4th x(:,3) = x(:,4);

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