How to delete a column with a specific value

In my case i would like to delete specific columns where for example the minimum value is 2e11;
This code below doesn't work, i get this error: Matrix index is out of range for deletion.
Error in reactionforce_script (line 16) reactionforce(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax, :) = []
code :
load ('Y:\Spoormodel\06\reactionforce2.mat');
%reactionforce2 = removevars(reactionforce, 3:2:end);
reactionforce2 = reactionforce;
reactionforce(4:2:end,:) = [];
reactionforce(:,3:2:end) = [];
%reactionforce(:,35:end) = []; %verwijderen van kolommen zonder waarde
reactionforce(1,:) = [];
reactionforce = table2array(reactionforce);
% thresholdmin = 2e11;
% thresholdmax = 2e30;
% reactionforce(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax, :) = []
%
reactionforce = array2table(reactionforce);
time = table2array(reactionforce(2:end,1));
data = reactionforce(2:end,2:end);
data = table2array(data(1:end,1:end));
plot (time,data);

3 Comments

Provide sample data
it is a 401x1032 table, these are some values
attach your .mat file

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 Accepted Answer

Error in reactionforce_script (line 16)
reactionforce(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax, :) = []
Well, yes that line is never going to work. If that line is meant to delete all rows for which any value in any columns but the first is outside the boundary, then:
reactionforce(any(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax), :) = [];

6 Comments

Jesse
Jesse on 5 Nov 2018
Edited: Jesse on 5 Nov 2018
still the same error,
Matrix index is out of range for deletion.
Error in reactionforce_script (line 16) reactionforce(any(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax), :) = []
Forgot to tell any to operate across the columns:
reactionforce(any(reactionforce(2:end,:) < thresholdmin | reactionforce(2:end,:) > thresholdmax, 2), :) = [];
However, I've just noticed to you convert your table to a matrix just to perform the deletion and then convert back to a table. That's a complete waste of time. You need to learn to manipulate tables directly.
To operate directly on the table, it's nearly the same syntax except you use {} to access the content of the table:
reactionforce(any(reactionforce{2:end,:} < thresholdmin | reactionforce{2:end,:} > thresholdmax, 2), :) = [];
Thanks! It starts to look like something... But, i would like to delete a entire column, if the minimum AND maximum value is between a range. This doens't do that. How can i achieve that?
I changed it to this
reactionforce(any(reactionforce{:,2:end} < thresholdmin | reactionforce{:,2:end} > thresholdmax, 2), :) = [];
I was a bit puzzled by your question as you asked about deleting columns but your original code deleted rows. So it's definitively columns you want to delete?
I'm not sure what " if the minimum AND maximum value is between a range" means. Do you mean you want to delete a column (which are called variables in a table) if all values are within the range? In which case:
reactionforce(all(reactionforce{2:end, :} >= thresholdmin & rectionforece{2:end, :} <= thresholdmax, 1), :) = [];
Note that since you're now looking at all values along the rows for a column, you use all(xxx, 1) instead of all(xxx, 2) (or any(xxx, 1) instead of any(xxx, 2))
Thanks for your help and excellent explanation, this is solving my problem.
+1 perfecto @Guillaume

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More Answers (1)

This is my file

2 Comments

Can you write that as a comment to the question, not an answer?
Next time i will do

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R2018a

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on 5 Nov 2018

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on 7 Nov 2018

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