Undefined function or variable 'isnan'
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Carver Nabb
le 7 Jan 2019
Commenté : Walter Roberson
le 19 Avr 2021
I am met with the error "Undefined function or variable 'isnan'" when running this code:
%counter = 1:4
%a is a 220x4 cell
%data is a 220x4 double
for i = size(a, 1)
pairs = [];
pairs(:,1) = counter;
pairs(:,2) = data(i,:);
pairs = pairs(~isnan(pairs(:,2),:));
slope(i) = polyfit(pairs(:,1),pairs(:,2),1);
end
I can't seem to figure out exactly why. Is the way I'm using the NOT operator?
3 commentaires
nanren888
le 7 Jan 2019
As Walter says; It is complaining about the two-parameter isnan(x,y) that you've invented :)
Réponse acceptée
Walter Roberson
le 7 Jan 2019
You have
pairs = pairs(~isnan(pairs(:,2),:));
You want
pairs = pairs(~isnan(pairs(:,2)),:);
21 commentaires
Plus de réponses (2)
Jan
le 7 Jan 2019
Although I assume that Walter hit the point already, I suggest to use teh debugger to identify such problems. Type in the command window:
dbstop if error
Now run the code again until it stops. Check the currently processed line by evaluating it piecewise:
% pairs = pairs(~isnan(pairs(:,2),:))
pairs(:,2)
~isnan(pairs(:,2),:) % <- This should fail already
pairs(~isnan(pairs(:,2),:))
As Walter has said already, isnan(x, :) is meaningful only, if it is an array. Otehrwise using the colon as second input is not valid, if the function isnan() is meant. The error message "Undefined function or variable 'isnan'" is not really clear here. But splitting the commands into parts using the debugger helps to understand the problem.
0 commentaires
Kholoud Alzoubi
le 19 Avr 2021
Undefined function or variable 'textdata'.
Error in KopackRFNNGOA (line 15)
x1=textdata(~isnan(textdata)); %temperature
1 commentaire
Walter Roberson
le 19 Avr 2021
Not enough context.
You are trying to use a variable named textdata that has not been assigned to.
Also, the variable name would tend to suggest that the variable is not expected to hold numeric data, so isnan() is questionable here.
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