**Next message:**C S P: "(pas d'objet)"**Previous message:**Daniel Chessel: "Re: NSCA et couplage"**Next in thread:**Daniel Chessel: "Re: COA:strength of linkages?"**Maybe reply:**Daniel Chessel: "Re: COA:strength of linkages?"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]

I'm using COA to compare the result of the classification of a

multi-temporal satellite image to

a set of 7 landcover maps of the Mediterranean Basin.

I have produced 7 contingency matrices and run COA on

each one.

I have a couple of questions.

1. Can I use the value of the first eigenvalue as

a measure of correpondence? Note that although

the contingency matrix has always the same number of rows

(because I'm always using the same classification), the number

of columns is different for each COA as the different landcover

maps have different legends with different number of

categories. Is there any way to take the number of columns

into account at evaluating the first eigenvalue?

I would say that I could use the ratio between the first observed

eigenvalue to the average eigenvalue from the permutation

test, would this be correct?

Or should I just use a Chi sq. coefficient?

2. If I plot the positions of rows and columns in the COA space

(i.e., the plane defined by the first two axes),

can the euclidean distances in the

COA space between a given row and a given column

be used as a measure of linkage? I think that there are some

problems with this practice.

Thanks,

Agus

Dr. Agustin Lobo

Instituto de Ciencias de la Tierra (CSIC)

Lluis Sole Sabaris s/n

08028 Barcelona SPAIN

tel 34 93409 5410

fax 34 93411 0012

alobo@ija.csic.es

http://pangea.ija.csic.es/alobo

**Next message:**C S P: "(pas d'objet)"**Previous message:**Daniel Chessel: "Re: NSCA et couplage"**Next in thread:**Daniel Chessel: "Re: COA:strength of linkages?"**Maybe reply:**Daniel Chessel: "Re: COA:strength of linkages?"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]

*
This archive was generated by hypermail 2b30
: Sat Feb 10 2001 - 10:36:01 MET
*