# Adjusting the node size in igraph using a matrix

I have the following network diagram:

```set.seed(1410)
df<-data.frame(
"site.x"=c(rep("a",4),rep("b",4),rep("c",4),rep("d",4)),
"site.y"=c(rep(c("e","f","g","h"),4)),
"bond.strength"=sample(1:100,16, replace=TRUE))

library(igraph)
df<-graph.data.frame(df)
V(df)\$names <- c("a","b","c","d","e","f","g","h")
layOUT<-data.frame(x=c(rep(1,4),rep(2,4)),y=c(4:1,4:1))
E(df)[ bond.strength < 101 ]\$color <- "red"
E(df)[ bond.strength < 67 ]\$color <- "yellow"
E(df)[ bond.strength < 34 ]\$color <- "green"
V(df)\$color <- "white"
l<-as.matrix(layOUT)
plot(df,layout=l,vertex.size=10,vertex.label=V(df)\$names,
edge.arrow.size=0.01,vertex.label.color = "black")
```

and would like to adjust the size of the nodes using a matrix such as this:

```m<-matrix(data=c(25,0,15,0,35,0,5,0,0,10,0,5,0,19,0,44), nrow=2, ncol=8)
colnames(m)<-c("a","b","c","d","e","f","g","h")
row.names(m)<-c("site.x","site.y")

a  b  c d  e f  g  h
site.x 25 15 35 5  0 0  0  0
site.y  0  0  0 0 10 5 19 44
```

You could use

```node.size<-setNames(c(25, 15, 35, 5, 10, 5, 19, 44),c("a", "b","c", "d", "e", "f", "g", "h"))
plot(df,layout=l,vertex.label=V(df)\$names,
edge.arrow.size=0.01,vertex.label.color = "black",vertex.size=node.size)
```

so basically a named vector.

```plot(df,layout=l,vertex.label=V(df)\$names,
edge.arrow.size=0.01,vertex.label.color = "black",vertex.size=as.matrix(node.size) )
```

would also work

UPDATE:

If you need to use your m matrix

```plot(df,layout=l,vertex.label=V(df)\$names,
edge.arrow.size=0.01,vertex.label.color = "black",vertex.size=m[m!=0])
```