Set specific values to NaN
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Hello everyone
My problem is as follows. I have a matrix like this for example:
A = [1 2 3 4 5 6 6 6 6;
2 4 3 5 4 6 7 7 7;
5 4 4 4 3 7 8 8 8;
2 1 3 3 3 3 3 3 5]'
Now i want to get a matrix which deletes the values which are similar (starting with the second) untill the end of the column. So columns 1, 2, 3 should delete some values while column 4 shouldn't delete any numbers.
At the end the matrix should look like this
A = [1 2 3 4 5 6 NaN NaN NaN;
2 4 3 5 4 6 7 NaN NaN;
5 4 4 4 3 7 8 NaN NaN;
2 1 3 3 3 3 3 3 5]'
I hope you get my problem. Thanks in Advance.
1 件のコメント
Peter Strassmann
2020 年 10 月 19 日
編集済み: Peter Strassmann
2020 年 10 月 19 日
Be aware that NaN values are only defined for data with single or double precision! It is resets integers to zero, e.g. uint8, int8.
rng(1);
A=randi([0,8], [100,1], "int8");
%A=double(A);
A(A>2)=nan;
If you want to associate NaN values to such data, you have to convert them first (before the remapping) with single(A) or double(A) into values with the according precision.
採用された回答
Stephen23
2017 年 4 月 13 日
編集済み: Stephen23
2017 年 4 月 14 日
>> A = [1,2,5,2;2,4,4,1;3,3,4,3;4,5,4,3;5,4,3,3;6,6,7,3;6,7,8,3;6,7,8,3;6,7,8,5];
>> idx = cumprod(double(diff(flipud(A))==0),1);
>> idx(end+1,:) = false;
>> idx = logical(flipud(idx));
>> A(idx) = NaN
A =
1 2 5 2
2 4 4 1
3 3 4 3
4 5 4 3
5 4 3 3
6 6 7 3
NaN 7 8 3
NaN NaN NaN 3
NaN NaN NaN 5
5 件のコメント
Stephen23
2017 年 4 月 14 日
Try this:
A = [1,2,3,4,5,6,6,6,6; 3,4,4,4,5,6,6,2,1; NaN,NaN,2,4,5,6,6,6,6; 1,2,2,2,2,2,NaN,NaN,NaN; NaN,NaN,NaN,NaN,NaN,NaN,NaN,NaN,NaN]'
idx = diff(flipud(A));
idx = cumprod(double(idx==0|isnan(idx)),1);
idx(end+1,:) = isnan(A(1,:));
idx = logical(flipud(idx));
A(idx) = NaN
which outputs this:
A =
1 3 NaN 1 NaN
2 4 NaN 2 NaN
3 4 2 NaN NaN
4 4 4 NaN NaN
5 5 5 NaN NaN
6 6 6 NaN NaN
NaN 6 NaN NaN NaN
NaN 2 NaN NaN NaN
NaN 1 NaN NaN NaN
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