unable to perform assignment because left and right sides have a different number of elements

Hello there,

I have this problem when implementing my main and my function called "due".

MAIN

clc
clear

format long
set(groot,'DefaultAxesFontSize',14) 
set(groot,'DefaultLineLineWidth',1.5)

load('Ex1T2_mistery_signal.mat');
sample = generateGoldCodeSampled(1,6.5e6,1.023e6,1);
corr = zeros(10,6500);

for i = 1:10
    corr(i,:) = due(i, sample);
    figure (i)

    plot (0:6499, corr(1,(0:6499)+1))
    grid on
end

FUNCTION DUE

function corr = due(PRN, signal_2)
    
    pseudo_signal = generateCAcode(PRN);
    signal_1 = zeros(1,6500);
    
    signal_1(1:1023) = pseudo_signal(1:1023);
    signal_1(1024:2047) = pseudo_signal(1:1023);
    signal_1(2048:3071) = pseudo_signal(1:1023);
    signal_1(3072:4095) = pseudo_signal(1:1023);
    signal_1(4096:5119) = pseudo_signal(1:1023);
    signal_1(5120:6143) = pseudo_signal(1:1023);
    signal_1(6144:6500) = pseudo_signal(1:1023);
    
    corr = zeros(1,6500);
    
    for k = 1:6500
        for j = 1:6500
            if (j+k-1 <= 6500)
                corr(1,k) = corr(1,k)+signal_1(j)*signal_2(j+k-1);
            else 
                corr(1,k) = corr(1,k)+signal_1(j)*signal_2(j+k-6501);
            end
        end
    end
end

In what way is the array assignment operation wrong?

Indeed, this is the error that I get!

Unable to perform assignment because the left and right sides have a different number of elements.

Error in due (line 7)
    signal_1(1024:2047) = pseudo_signal(1:1023);

Error in maindue (line 13)
    corr(i,:) = due(i, sample);

PS

pseudosignal is just a sequence of +1 and -1.

Thank you!

Answer 1

[Jan]

The error message is clear: The number of elements of the left and righ side differs. Try this:

% signal_1(1024:2047) = pseudo_signal(1:1023);
size(1024:2047)
size(1:1023)

It is not clear, how you want to concatenate a [1 x 1023] vector to get a [1 x 6500] vector. The last block 6144:6500 has 357 elements only and you cannot assign a [1 x 1023] vector to it.

Maybe you mean:

signal_1 = repmat(pseudo_signal(1:1023), 1, 7);

but this has 7161 elements, not 6500.

[john_arle]

Hello Jan,

thank you for your answer, and sorry to bother for that stupid mistake. Yes, I want to concatenate the array 6 times plus the first 357 element of itself. Do you know a rapid way to do it?

[john_arle]

I found out. thanks.