Vectors must be the same length

N1=64;
Y1=fft(y,N1);
x= (0:29);
subplot(3,1,2)
plot(x,abs(Y1))
xlabel('Frequency (Hz)');
ylabel('Amplitude');

%HOW TO MAKE IT SAME LENGTH?(LINE5)

Answer 1

[Star Strider]

The number of elements in ‘Y1’ in the plot need to be the same as the number in ‘x’ so one way would be to re-define ‘x’ to be the desired length with respect to ‘Y1’ and another would be:

plot(x,abs(Y1(1:numel(x))))

Use the approach that gives the desired result.

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[Mya]

% I dun understand...if i add nume1.....the MATLAB won't recognize it

[Mya]

so how to make Y1 same as x?

[Star Strider]

It is not necessary toi make the entire vector the same size, only the range desired in the plot. That is what the code I posted does.

To make ‘x’ the same size as ‘Y1’ create it as:

x = linspace(0, numel(Y1), numel(Y1));

The length of ‘Y1’ is fixed by ‘N’ and since that governs everythin else, it creates another option:

x = 0:N-1;

Choose the one that gives the desired result.

.

[Mya]

ok tq for ur guide

[Star Strider]

As always, my pleasure!

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