working with numbers in the array names in for/ if loop

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Sonali 2023-10-22

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评论： Dyuman Joshi 2023-10-26

I am struggling with a program in matlab where I need to make arrays with numbers varying in their name in the loop itself:

For example: given dataset with columns: data_column_1, data_column_2, data_column_3 . . . upto 10

Lets say:

………………………….

For i=1:10
array_(i)= mean(data_column_(i) w.r.t data_column_1 )     %( for all 10  arrays )
end

………………………………..

Solution must be like

array_1 has mean of data in data_column_1 wrt data_column_1

array_2 has mean of data in data_column_2 wrt data_column_1

array_3 has mean of data in data_column_3 wrt data_column_1 and so on.

I will really appreciate some solution here. Thanks

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Stephen23 2023-10-23

"I will really appreciate some solution here"

Use indexing.

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

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回答（1 个）

Dyuman Joshi 2023-10-22

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Dynamically naming variables is not a good coding practice.

Read - TUTORIAL: Why Variables Should Not Be Named Dynamically (eval)

As you have numbers only, you should concatenate all the data in a numerical array and directly use mean with the specific dimension.

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Dyuman Joshi 2023-10-23

在 MATLAB Online 中打开

From what I understood by the description you gave, try this -

(I didn't understand the bit about the 10 bins.)

idx = findgroups(arr(:,1));
u = unique(idx);
c = zeros(numel(u),3);
for j=1:3 
    c(:,j)=splitapply(@mean,arr(:,j),idx);
end
figure
plot(c(:,1), c(:,2), 'b.')
hold on
plot(c(:,1), c(:,3), 'r.')

If this does not work, please attach the data for "arr".

Dyuman Joshi 2023-10-26

Any updates, @Sonali?

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