how to save variable data that we changed ?

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NUR BATRISYIA HANNANI ZAIN AZMI 2021-3-9

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https://ww2.mathworks.cn/matlabcentral/answers/766891-how-to-save-variable-data-that-we-changed

回答： KALASH about 11 hours 前

this is my code:

nSamp = 3251;
Fs = 1024e3;
SNR = 40;
rng default
t = (0:nSamp-1)'/Fs;
x = sin(2*pi*t*100.123e3);
x = x + randn(size(x))*std(x)/db2mag(SNR);
[Pxx,f] = periodogram(x,kaiser(nSamp,38),[],Fs);
meanfreq(Pxx,f);

i change the variable in this code to my dataset . then after run, the variable go to its original data . how to solve this problem?

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Walter Roberson 2021-3-11

What is the source of your signal? Is it stored in a .mat file at the moment? Does it need to be read from a .wav ?

NUR BATRISYIA HANNANI ZAIN AZMI 2021-3-11

yes in mat file .

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回答（1 个）

KALASH about 11 hours 前

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Hi @NUR BATRISYIA HANNANI ZAIN AZMI,

I understand that you want to change the value of a variable in the workspace. The problem you are facing is because you are changing the values in the workspace but that is not the right way as the variables in the workspace are generated after the script is executed.

So, changing the values in the workspace won’t help as when you run the script again it will generate the values according to the code and not take the values of the workspace.

So, to change any value of the variable you must modify the script. You can make your code as a function and then call it as shown below:

function plotPeriodogram(x) 
nSamp = numel(x); 
Fs = 1024e3; 
SNR = 40; 
rng default 
x = x + randn(size(x)) * std(x) / db2mag(SNR); 
[Pxx, f] = periodogram(x, kaiser(nSamp, 38), [], Fs); 
meanFreq = meanfreq(Pxx, f); 
disp(['Mean Frequency: ', num2str(meanFreq)]); 
end 
plotPeriodogram(myNewData); 