how to replace NaN values with zero?
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Hello,
I have a matrix of 361*181 dimention, which contain NaN and some values.
I want to replace those NaN values with 0, I have tried A(isnan(A))=0; command but is showing error.
the error read as " Subscript indices must either be real positive integers or logicals".
can anyone help me out this?
2 Comments
Walter Roberson
on 31 Dec 2018
What shows up for
which -all isnan
Puspa patra
on 31 Dec 2018
Accepted Answer
madhan ravi
on 31 Dec 2018
Edited: madhan ravi
on 31 Dec 2018
Might happen that your isnan is somehow a variable maybe try the following:
clear all
A(isnan(A))=0;
%%%% an example
A=rand(3);
A([2 3],2)=NaN;
A(isnan(A))=0;
Gives:
A =
0.7339 0.8422 0.1934
0.0039 0 0.3316
0.1183 0 0.6213
12 Comments
Puspa patra
on 31 Dec 2018
madhan ravi
on 31 Dec 2018
In case if you didn‘t notice mine has clear all at the very beginning which is used to clear the variables from the workspace in case if you have any variable named isnan it will be cleared , this is one way of clearing the error.
madhan ravi
on 31 Dec 2018
Type in command window the following and paste the output here
whos isnan
whos A
which isnan -all
Puspa patra
on 31 Dec 2018
Puspa patra
on 31 Dec 2018
Walter Roberson
on 31 Dec 2018
isnan is a variable.
That is the important point. You assigned something to isnan at some point, which damages the ability to use isnan() as a function.
madhan ravi
on 31 Dec 2018
See as I told you , it's a variable
The solution is
clear isnan
% or
clear all
% or
clear global
Puspa patra
on 31 Dec 2018
madhan ravi
on 31 Dec 2018
Anytime :)
Fabricio Arturo Balboa Cavazos
on 1 Apr 2021
Thanks madhan ravi!
Ashishkumar Gupta
on 5 Jan 2023
Tried ur code for my problem (https://de.mathworks.com/matlabcentral/answers/1889142-how-to-remove-nans-from-struct) but did not work out!!
I want to replace all the NaN with 0 so that size is same for future use.
Ashishkumar Gupta The png attachments in your linked post are not informative. It might be you are not accessing the structure data correclty to get the value you wish to set to zero.
For example, you have a struct named WS_struct with several fields. To access the values (and assuming they are numeric), you would type: WS_struct.HP_EDU_00571_eTA
Just be sure that the fields give numeric data and you correctly access the data. The data fields in the other pic are double, so the method outlined about should work and you can explore with this code how to manipulate the struct fields and set to new named varibles and access entries:
%% example code to set all nan entries to zero after accessing from a struc file
clear all; clc;
M = 5*rand(5,5); % make a 5x5 matrix with random nums on [0,5]
n = randi([1 3],1); % rand num from 1 to 3 to use as the num of nans
randRows = randi([1 5],n,1); % get n rand rows from the 5 cols
randCols = randi([1 5],1,n); % get n rand cols from the 5 cols
fprintf('\nA random 5x5 matrix with 1 to 9 random nan entries:\n');
M(randRows,randCols) = nan
% Now create a structure with field randM and set to M
S.randnum = n;
S. randRows = randRows
S. randCols = randCols;
S.randM = M;
save('randomMatrix.mat','S'); % save structure S
% clear all memory and access data directly from struct S
clear all; % mimicking someone handing you the structure for the first time
load randomMatrix.mat
% set matrix newM to S.randM
newM = S.randM;
fprintf('\nSetting all nan entries to zero:\n');
newM(isnan(newM)) = 0 % find nan entries and set to zero
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