Re: [igraph] Fwd: scale-free/preferential attachment matrix

[George Vega Yon]

Let M={m_ij} be a square matrix of size n, then m_ij = 1 iff x_j="A" and i != j. If you want to build something like that, then this should work:

rm(list=ls())

x   <- c("A", "A", "B", "B", "A")

y   <- rep("A", length(x))

# An entry in mat will be 1 iff target == "A"

M <- outer(y, x, "==")

M[] <- as.integer(M)

diag(M) <- 0

dimnames(M) <- list(x,x)

M

# A nicer way of printing it

library(Matrix)

methods::as(M, "dgCMatrix")

> methods::as(M, "dgCMatrix")
5 x 5 sparse Matrix of class "dgCMatrix"
  A A B B A
A . 1 . . 1
A 1 . . . 1
B 1 1 . . 1
B 1 1 . . 1
A 1 1 . . .

Best,

George G. Vega Yon
+1 (626) 381 8171
http://cana.usc.edu/vegayon

On Tue, Dec 27, 2016 at 11:41 AM, Sebastián Goinheix <address@hidden> wrote:

​Hi:

I tried the outer function but I couldn't fix it.

The solution you suggest is another way of generate homophilia matrices (linking vertices with equal characteristics). Actually what I need is to generate links between all the nodes and those that have a specific attribute, as:

  A A B B B

A 0 1 1 1 1

A 1 0 1 1 1

B 1 1 0 0 0

B 1 1 0 0 0

B 1 1 0 0 0

Any ideas?

thank you very much!

--------

Sebastián Goinheix
Instituto de Economía - UdelaR

Tel: 24001369 (int. 116)

Por favor, evite imprimir este correo.

2016-12-21 23:24 GMT-03:00 Sebastián Goinheix <address@hidden>:

Thanks George

--------

Sebastián Goinheix
Instituto de Economía - UdelaR

Tel: 24001369 (int. 116)

Por favor, evite imprimir este correo.

2016-12-21 16:33 GMT-03:00 George Vega Yon <address@hidden>:

Does this works?

rm(list=ls())

x   <- c("A", "A", "B", "B", "B")

mat <- outer(x, x, "==")

mat[] <- as.integer(mat)

dimnames(mat) <- list(x,x)

mat

> mat

  A A B B B

A 1 1 0 0 0

A 1 1 0 0 0

B 0 0 1 1 1

B 0 0 1 1 1

B 0 0 1 1 1

Best,

George G. Vega Yon
+1 (626) 381 8171
http://cana.usc.edu/vegayon

On Wed, Dec 21, 2016 at 9:21 AM, Sebastián Goinheix <address@hidden> wrote:

Hi,

​​

​

​

​​

I want to perform network regresion with QAP procedure (netlm function of sna package).

​I ​have matrices with some inter-organizational relations, and with ​calculated matrices for homophily hypotheses through the bipartite.projection function. 

But now I need a matrix that contains links from all nodes to those that have a specific attribute, say "A". For example:

nodes attributes
1 A
2 A
3 B
4 B
5 B

Therefore, the resulting adjacency matrix will be:

  1 2 3 4 5
1 0 1 1 1 1
2 1 0 1 1 1
3 1 1 0 0 0
4 1 1 0 0 0
5 1 1 0 0 0 
​​

​​

I assume the sample_pa function will not work since the network is based on vertex attributes

 and​

 the model should not be random

​.​

How can I get it in Igraph (or other)?
Thanks

--------

Sebastián Goinheix
Instituto de Economía - UdelaR

Tel: 24001369 (int. 116)

Por favor, evite imprimir este correo.

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