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Asked by Xiu
on 11 Jul 2012

Hi,

I have problems using function isempty(x) when x is in the class of dataset. For example,

>> x=randn(100,10); >> xx=dataset(x); >> isempty(xx) ??? Reference to non-existent field 'nobs'.

Error in ==> dataset.isempty at 11 t = (a.nobs == 0) (a.nvars == 0);

I think this is because when I use 'dataset', only certain fields are created, which does not include the field 'nobs'. When isempty.m tries to locate this field, the error occurs. However, I am not sure how to solve this problem. Can anyone help me with this please?

Thanks in advance.

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## 8 Comments

## Thomas

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89119

Works fine for me: What version of MATLAB are you using?

## Xiu

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89126

I am using MATLAB 2010a

## Thomas

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89127

I cannot test on R2010a but I can assure you it works from R2010b Sp1 onwards.. What OS are you on? Windows, Linux ,OSX?

## Xiu

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89128

I am using Windows.

## Matt Tearle

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89134

I just tried it on 10a and it worked fine. The error seems to indicate that it doesn't recognize the nobs property. But it's using the dataset version of isempty, so it should... Very odd. Something messed up in your installation, perhaps?

Just as a sanity check, try

>> which dataset(x)

and

>> which isempty(xx)

## Sean de Wolski

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89145

Not reproducing for me on 12a:

## Xiu

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89170

I have figured the problem. I have additional toolbox in my matlab which contains another dataset.m file. Once I removed it, it is working perfectly fine. Thanks for all your helps.

## Sean de Wolski

Direct link to this comment:http://www.mathworks.com/matlabcentral/answers/43351#comment_89172

Excellent!

Xiu, please write your comment as an answer and accept it to mark this question closed!