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Sun, 27 Jun 2010 14:22:06 +0000
what distance metric is this?
http://nl.mathworks.com/matlabcentral/newsreader/view_thread/285585#757904
shahnaz fatima
v=double(x)*double(x');<br>
d(i,j)=sqrt(v(i,i)+v(j,j)2*v(i,j)); %%%% what is this distance metric called?????<br>
<br>
can anybody explain.

Sun, 27 Jun 2010 15:22:04 +0000
Re: what distance metric is this?
http://nl.mathworks.com/matlabcentral/newsreader/view_thread/285585#757920
Roger Stafford
"shahnaz fatima" <shahnaz1981fat@gmail.com> wrote in message <i07mqe$i8e$1@fred.mathworks.com>...<br>
> v=double(x)*double(x');<br>
> d(i,j)=sqrt(v(i,i)+v(j,j)2*v(i,j)); %%%% what is this distance metric called?????<br>
> <br>
> can anybody explain.<br>
        <br>
It looks very much like the Euclidean metric in R^n between the rows of x where n is the number of columns in x.<br>
<br>
Roger Stafford

Sun, 27 Jun 2010 15:32:05 +0000
Re: what distance metric is this?
http://nl.mathworks.com/matlabcentral/newsreader/view_thread/285585#757922
John D'Errico
"shahnaz fatima" <shahnaz1981fat@gmail.com> wrote in message <i07mqe$i8e$1@fred.mathworks.com>...<br>
> v=double(x)*double(x');<br>
> d(i,j)=sqrt(v(i,i)+v(j,j)2*v(i,j)); %%%% what is this distance metric called?????<br>
> <br>
> can anybody explain.<br>
<br>
Euclidean distance.<br>
<br>
But done very poorly, because it uses a doubly nested<br>
loop to do work that is far better done with no explicit<br>
loops at all.<br>
<br>
Even worse, it is inaccurate and subject to numerical<br>
problems in some cases. <br>
<br>
A better tool can be found here:<br>
<br>
<a href="http://www.mathworks.com/matlabcentral/fileexchange/18937">http://www.mathworks.com/matlabcentral/fileexchange/18937</a><br>
<br>
John

Sun, 27 Jun 2010 16:03:06 +0000
Re: what distance metric is this?
http://nl.mathworks.com/matlabcentral/newsreader/view_thread/285585#757926
Faraz Afzal
"shahnaz fatima" <shahnaz1981fat@gmail.com> wrote in message <i07mqe$i8e$1@fred.mathworks.com>...<br>
> v=double(x)*double(x');<br>
> d(i,j)=sqrt(v(i,i)+v(j,j)2*v(i,j)); %%%% what is this distance metric called?????<br>
> <br>
> can anybody explain.<br>
<br>
Hi<br>
<br>
This look to me like a Euclidean metric in the nth space. Mapping v's for the given xs.<br>
If you have a Square matrix data use Chebyshev distance for much efficiency.<br>
<br>
I hope it answers the question. Let us know what you are trying to achieve?<br>
<br>
Regards,<br>
Faraz Afzal