## Finding columns that contain both integers and NaN

Ahmed Hamed

### Ahmed Hamed (view profile)

さんによって質問されました 2016 年 2 月 4 日

### the cyclist (view profile)

さんによって コメントされました 2016 年 2 月 4 日
I have a matrix that contain Numerical values (float) and Categorical values (Int)
as
A = 1 NaN 2.2 3.2 4
NaN 7.9 5.1 NaN 5
3 5.5 NaN 4.1 NaN
and I'd like to split it into matrices;
one contains the Int values and the other contains the float values as
it = 1 4
NaN 5
3 NaN
and
flt = NaN 2.2 3.2
7.9 5.1 NaN
5.5 NaN 4.1
i use the following code
int_cols = all( round(A)==A, 1 ); %// logical indexing into integer columns
it = A(:,int_cols);
flt = A(:,~int_cols);
However, NaN isn't equal NaN so it appears in the flt matrix and it = [].
Are there any function that can help?

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## 2 件の回答

### David Young (view profile)

2016 年 2 月 4 日

Yes, isnan(x) does what x == NaN would do if NaNs were equal to each other.

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### the cyclist (view profile)

2016 年 2 月 4 日

int_cols = all( round(A)==A | isnan(A), 1 ); %// logical indexing into integer columns
it = A(:,int_cols)
flt = A(:,~int_cols)

the cyclist

### the cyclist (view profile)

2016 年 2 月 4 日
If the entries in A are have been computed in prior operations, you might also want to guard against floating point inaccuracies, such as the value "4" actually being 4.0000000000001. You could check for equality to within a specific tolerance, for example.

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