How to Normalize a matrix between 0-1 containing NaNs?
5 views (last 30 days)
Show older comments
Can anyone help me please to normalize a matrix between 0-1 which contains NaNs?
the following makes whole the matrix zero
d = A - min (A(:));
nrmdata = d./max(d(:));
2 Comments
Walter Roberson
on 5 Sep 2016
I do not seem to be able to reproduce the problem. Could you attach a .mat with your A values?
Answers (3)
KSSV
on 5 Sep 2016
Edited: KSSV
on 5 Sep 2016
clc; clear all ;
load A.mat ;
idx = isinf(A) ; % get the positions of inf in A
B = A ; % B as A
B(idx) = 0 ; % repalce inf's in B with 0
% normalize the B matrix
norm_A = (B - min(B(:))) / ( max(B(:)) - min(B(:)) ) ;
norm_A(idx) = inf ; % replace norm_A with inf in previous locations/ if required
or
clc; clear all ;
load A.mat ;
m0 = min(A(isfinite(A(:)))); % get minimum in A
m1 = max(A(isfinite(A(:)))); % get maximum in A
norm_A = (A -m0)/(m1-m0 ) ;
0 Comments
Walter Roberson
on 5 Sep 2016
You cannot normalize data that contains infinity, not unless you are willing to ignore the infinity.
By definition, any finite real value is a negligible fraction of infinity, so when you normalize against infinity, all finite values become 0.
0 Comments
Stephen23
on 5 Sep 2016
Ignoring infinity:
S = load('A.mat');
A = S.A;
idx = isfinite(A);
Amax = max(A(idx));
Amin = min(A(idx));
B = (A-Amin) / (Amax-Amin);
and checking:
>> min(B(isfinite(B)))
ans = 0
>> max(B(isfinite(B)))
ans = 1
0 Comments
See Also
Categories
Find more on Logical in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!