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Topic: ClassificationKNN.fit with cell array of strings as Y
Replies: 8   Last Post: May 8, 2013 4:39 AM

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 Alan Weiss Posts: 1,430 Registered: 11/27/08
Re: ClassificationKNN.fit with cell array of strings as Y
Posted: May 7, 2013 12:55 PM

On 5/7/2013 11:07 AM, Jay wrote:
>
>> I am not sure where in the documentation you found your statement 1.
>> Here's what I see when I look at the current documentation:
>> http://www.mathworks.com/help/stats/classificationknn.fit.html
>>
>> Y - Grouping variables of response values with the same number of
>> elements (rows) as X. Each entry in Y is the response to the data in
>> the corresponding row of X.
>>
>> This does not say that the variable must be a numeric vector, but a
>> grouping variable
>> http://www.mathworks.com/help/stats/grouping-variables.html

>
> Hm, yes, correct. Here is what I was referring to:
> http://www.mathworks.de/de/help/stats/classificationknnclass.html
>
> Y Numeric vector of response values with the same number of rows as
> X. Each entry in Y is the response to the data in the corresponding
> row of X.
>

>> As far as your problem 2, I am not sure what is going on. I wonder if
>> your function myDistance is giving you a problem somehow.

>
> So you believe everything should work fine when using a cell array of
> strings. I don't see how my distance function could cause such an
> error. My distance function is defined as [ distance ] = myDistance(
> obj1, objects)
> and will always return at least "distance = zeros(size(objects, 1),1);
> " or higher values.

There must be something strange about the German web site, because when
I try to look at the documentation page for the ClassificationKNN class,
I do not see the "Numeric vector..." that you do, even when I look at
the R2012b version of the documentation. I will try to investigate this
discrepancy. Thanks for reporting the issue.

And, as I said, I really do not know what is going on with the predict
method that is causing those errors. I will try to look into it, but it
might take a few days.

Alan Weiss
MATLAB mathematical toolbox documentation

Date Subject Author
5/7/13 Jay
5/7/13 Alan Weiss
5/7/13 Jay
5/7/13 Alan Weiss
5/7/13 Alan Weiss
5/7/13 Steven Lord
5/7/13 Ilya Narsky
5/8/13 Jay
5/8/13 Jay