Replace NaN with median per column

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Konvictus177
Konvictus177 am 10 Aug. 2021
Beantwortet: Yazan am 10 Aug. 2021
Hi,
I have a matrix where I have NaN values in a few columns.
I would like to fill the NaN values with the median value of that column. How do I do that?

Antworten (4)

KSSV
KSSV am 10 Aug. 2021
Bearbeitet: KSSV am 10 Aug. 2021
Read about fillmissing.
Or USe:
A = rand(20,1) ; % data for demo
A(randperm(20,5)) = NaN ; % insert nans
M = nanmedian(A) ; % get median
A(isnan(A)) = M % replace nans with medians

Wan Ji
Wan Ji am 10 Aug. 2021
It is convenient to use fillmissing function to get what you want
matOut = fillmissing(matrixIn, 'linear', 'EndValues','nearest')
  4 Kommentare
Yazan
Yazan am 10 Aug. 2021
This does linear interpolation of neighboring non-nan values. It does not replace nan values with the median.
Wan Ji
Wan Ji am 10 Aug. 2021

Melden Sie sich an, um zu kommentieren.


Stephen23
Stephen23 am 10 Aug. 2021
Bearbeitet: Stephen23 am 10 Aug. 2021
M = randi(3,5,7);
M(randi(numel(M),1,9)) = NaN
M = 5×7
1 NaN 1 1 2 3 1 NaN 1 2 NaN 1 1 3 NaN 3 NaN 1 2 1 NaN 2 NaN 3 2 3 2 2 1 1 2 NaN 1 3 2
V = median(M,1,'omitnan')
V = 1×7
1 1 2 1 2 2 2
X = isnan(M);
M(X) = repelem(V,sum(X,1))
M = 5×7
1 1 1 1 2 3 1 1 1 2 1 1 1 3 1 3 2 1 2 1 2 2 1 3 2 3 2 2 1 1 2 1 1 3 2

Yazan
Yazan am 10 Aug. 2021
clc, clear
x1 = randn(5, 5);
x1(randi(numel(x1), 1, 5)) = nan;
x2 = fillmissing(x1, 'movmedian', size(x1,1)*2, 1);
display(x1)
x1 = 5×5
NaN 0.1826 NaN 0.3875 -0.7928 1.3983 -0.1527 0.1261 0.1482 -0.8491 1.4623 0.7005 -0.0511 -0.1259 1.1562 0.8948 0.0311 0.0064 NaN NaN -0.2615 -0.1371 -1.7245 0.9723 0.5918
display(x2)
x2 = 5×5
1.1466 0.1826 -0.0223 0.3875 -0.7928 1.3983 -0.1527 0.1261 0.1482 -0.8491 1.4623 0.7005 -0.0511 -0.1259 1.1562 0.8948 0.0311 0.0064 0.2678 -0.1005 -0.2615 -0.1371 -1.7245 0.9723 0.5918

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