Error using reshape, To RESHAPE the number of elements must not change?

function mod_out=modulation(mod_in,mod_mode)
%function discription:
%Input::The sequence to be modulated
%Output: mod_out,The output after modulation
switch (mod_mod)
case 2
        for i=1:length(mod_in)%  The sequence to be modulated
             if mod_in(i)==0
               mod_out(i)=-1;
           else
              mod_out(i)=1;%the contellation mapping
           end
     end
disp(mod_out);
cose 4
     mod_out=zeros(1,length(mod_in)/2);
     R=reshape(mod_in,2,length(mod_in)/2); %Convert the input sequence to a matrix of (2,length(x)/2)
    B2D=bi2de(R','left-msb')+1;%Convert binary to decimal
    Temp=[-1-1j -1+1j 1-1j 1+1j];
    for  i=1:length(mod_in)/2
          mod_out(i)=Temp(B2D(i))/sqrt(2);%Nomalized
    end
end

the error"R=reshape(........)

I need help！

[madhan ravi]

when you ask a question , provide all the datas(values) to run your code

[long zhang]

thanks, got it!

Answer 1

[Matt J]

Try this,

R=reshape(mod_in,2,[]);

[long zhang]

it's right ! but I don't clear! Could you explain that,please? thanks!

[Matt J]

You could also have done

 R=reshape(mod_in,2,numel(mod_in)/2);

but since you know that the number of rows in the reshaped matrix is 2, there is only one thing the number of columns can be, so putting a [] there instead tells reshape to calculate it automatically.

[madhan ravi]

+1

[long zhang]

I see! thanks a lot！：）

[Jan]

@long zhang: Please use flags only to informa admins and editors about message, which might collide with the terms of use, e.g. spam or rudeness. Thanks.