igraph-help
[Top][All Lists]

## Re: [igraph] eigenvector cumulative distribution

 From: simone gabbriellini Subject: Re: [igraph] eigenvector cumulative distribution Date: Wed, 18 Mar 2009 17:26:47 +0100

```Gabor,

```
Following "On power-law relationships of the internet topology" by Faloutsos, Faloutsos and Faloutsos it looks like they never use cumulative frequencies, or they never use frequencies at all... they simply, for example, sort the nodes in decreasing order of outdegree (or eigenvector) and plot it against the rank of the node (its index in the order of decreasing outdegree).
```
```
However, in "Towards a Theory of Scale-Free Graphs: Deﬁnition, Properties, and Implications" by Lun Li, David Alderson , John C. Doyle, Walter Willinger it looks like cumulative size-rank log-log plots are the more reliable tool for investigatin such type of relations.
```
```
but I have to admit I am walking on eggs... so I welcome every suggestion that can point me to understand if the evolution of my network has some scale-free properties.
```
best,
Simone

Il giorno 18/mar/09, alle ore 13:27, Gábor Csárdi ha scritto:

```
```Simone,

On Wed, Mar 18, 2009 at 1:16 PM, simone gabbriellini
```
```Dear List,

```
I see that it is always advisable to use cumulative log-log plot, like the
```one on the igraph screenshot page
```
```
I think this is not _always_ the case. If you have a power-law or
exponential distribution, then the cumulative distribution is a
power-law/exponential, too; and the cumulative distribution has less
fluctuations usually.

```
(http://igraph.sourceforge.net/screenshots2.html#8), when investigating for
```power law distributions...

```
I was wondering how to build a cumulative distribution of eigenvalues.
```
using for example:

eigen<-evcent(g, scale=TRUE, weights = E(g)\$weights)
eigenvector<-eigen\$vector
dd<-as.numeric(table(eigenvector))
dd<-dd/sum(dd)

I have a non cumulative distribution. How to make it cumulative?
```
```
rev(cumsum(rev(dd)))

Gabor

```
```best regards,
Simone

_______________________________________________
igraph-help mailing list
http://lists.nongnu.org/mailman/listinfo/igraph-help

```
```

--

_______________________________________________
igraph-help mailing list
```