Re: change in polyfit()'s behaviour?

[Thomas Weber]

On Sat, Jan 03, 2009 at 01:04:52PM -0500, Ben Abbott wrote:
>
> On Jan 3, 2009, at 11:47 AM, Thomas Weber wrote:
>
>> Hi,
>>
>> the following raises in error in the 3.0 branch:
>>      
>>      polyfit ([1,2; 3,4], [1,2; 3,4],4)
>> namely
>> error: polyfit: x and y must be vectors of the same size
>>
>> In fact, this error is part of test_poly.m in the test/ subdirectory.
>>
>>
>> In the development sources, the test has been removed and the output  
>> is
>> now:
>>
>> octave:1> polyfit ([1,2; 3,4], [1,2; 3,4],4)
>> ans =
>>
>>   0.011358  -0.113585   0.397547   0.432076   0.272603
>>
>> Is this change intentional, ie should polyfit handle matrices as input
>> arguments?
>>
>>      Thomas
>
> It is compatible behavior, so it should accept matrices, provided they  
> are the same size.

Ah, okay. I wonder whether this behaviour is intentional, though.

> It *may* be sensible to add the warning regarding the equations  
> exceeding the unknowns. However, QR calculates the minimum-norm which I 
> understand is unique. So I'm inclined to leave it as it is.

Fine with me, thanks for the explanation.

        Thomas