Effacer les filtres
Effacer les filtres

Removing NaN from matrix

519 vues (au cours des 30 derniers jours)
Christian
Christian le 19 Avr 2017
Hello everybody,
I have a 61x9 double matrix. The columns look like this:
Column 1: 0 1 2 3 4 5 6 7 ... NaN NaN NaN
Column 2: 0 2 3 4 5 6 7 8 4 5 6 3 NaN NaN
Column 3: 0 5 6 6 3 3 6 7 8 5 3 3 6 7 8 5 . . .
That means, every column has a certain amount of values and is filled up with NaNs to get a rectangular double matrix all in all.
Now I want to remove all the NaNs. And I am not quite sure if this is possible, because after removing the NaNs, the size of each column would differ.
For now I have tried something like this:
A(find(isnan(A)))=[]
This code removes the NaNs, but the result is a 1x445 double, where all columns are just add consecutively.
I hope you guys can help me!
Cheers
Christian
  2 commentaires
Ganesh Hegade
Ganesh Hegade le 19 Avr 2017
Its better you should replace the NaN with some values.
A(isnan(A)) = -1;
Pampa Dey
Pampa Dey le 25 Août 2021
how to remove nans from a column?
I have multiple .txt files in which some of them have completely nan values within my interested column how can we remove them in matlab?
could anyone please help?

Connectez-vous pour commenter.

Réponse acceptée

Jan
Jan le 19 Avr 2017
Exactly: This cannot work, because all columns of a matrix must have the same number of rows. You cannot remove all NaNs and keep the shape of the matrix. You have to decide, what you want instead:
X = X(~any(isnan(X, 2)))
X = X(~all(isnan(X, 2)))
X = X(~isnan(X))
Or perhaps you want a cell array containing the different columns vectors?
  2 commentaires
Christian
Christian le 19 Avr 2017
Ok, that's what I thought. So I will continue using cells instead.
Ashishkumar Gupta
Ashishkumar Gupta le 5 Jan 2023
did not work for a .struct!!!
Any other way out to remove NaNs from a struct having 50-60 variables

Connectez-vous pour commenter.

Plus de réponses (1)

Biswajit Ojha
Biswajit Ojha le 30 Avr 2019
"X = X(~any(isnan(X, 2)))
X = X(~all(isnan(X, 2)))
X = X(~isnan(X)) "
dear Jan,
can you please explain why you have used those '2' s in the command?
  1 commentaire
Yuanhanqing Huang
Yuanhanqing Huang le 25 Juil 2019
I think there are some little errors. Maybe the right code should be:
X = X(~all(isnan(X), 2))
It means that we find the rows the elements of which are all nan. '2' denotes the results are in column. That being said, the any operation is implemented regarding each row.

Connectez-vous pour commenter.

Catégories

En savoir plus sur Data Type Identification dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by