Hi the list,
According to what I know, the Canberra distance between X et Y is : sum[
(|x_i - y_i|) / (|x_i|+|y_i|) ] (with | | denoting the function
'absolute value')
In the source code of the canberra distance in the file distance.c, we
find :
sum = fabs(x[i1] + x[i2]);
diff = fabs(x
On 06/02/2010 10:39 AM, Christophe Genolini wrote:
Hi the list,
According to what I know, the Canberra distance between X et Y is : sum[
(|x_i - y_i|) / (|x_i|+|y_i|) ] (with | | denoting the function
'absolute value')
In the source code of the canberra distance in the file distance.c, we
fin
The definition I use is the on find in the book "Cluster analysis" by
Brian Everitt, Sabine Landau and Morven Leese.
They cite, as definition paper for Canberra distance, an article of
Lance and Williams "Computer programs for hierarchical polythetic
classification" Computer Journal 1966.
I do n
I guess there is also a problem in the binary distance since
x <- y <- rep(0,10)
dist(rbind(x,y),method="binary")
gives 0 whereas it suppose to be undefine. (the aka asymmetric binary is
not suppose to take in account the (off,off) couples in its calculation)
Christophe
The definition I use
On 06/02/2010 11:31 AM, Christophe Genolini wrote:
The definition I use is the on find in the book "Cluster analysis" by
Brian Everitt, Sabine Landau and Morven Leese.
They cite, as definition paper for Canberra distance, an article of
Lance and Williams "Computer programs for hierarchical polyt
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On 06/02/2010 18:10, "Duncan Murdoch" wrote:
> On 06/02/2010 10:39 AM, Christophe Genolini wrote:
>> Hi the list,
>>
>> According to what I know, the Canberra distance between X et Y is : sum[
>> (|x_i - y_i|) / (|x_i|+|y_i|) ] (with | | denoting the function
>> 'absolute value')
>> In the so
That is interesting. The first of these, namely
sum(|x_i - y_i|) / sum(x_i + y_i)
is now better known in ecology as the Bray-Curtis distance. Even more
interesting is the typo in Henry & Stevens "A Primer of Ecology in R" where the
Bray Curtis distance formula is actually the Canberra distanc
This is cetainly ancient R history. The essence of the formula was
last changed
- dist += fabs(x[i1] - x[i2])/(x[i1] + x[i2]);
+ dist += fabs(x[i1] - x[i2])/fabs(x[i1] + x[i2]);
in October 1998. The help page description came later.
The
dist += fabs(x[i1] - x[i2
