Re: [igraph] How to test if there is any relationship between attributes of edges and nodes

[Tamás Nepusz]

> I want to test two hypothesis:
> 1) When V(g)$size increases for one or both nodes, E(g)$weight of the  
> connecting edge also increases;
> 2) When the difference between the two V(g)$time decreases (thus the  
> event happens closer in time), E(g)$weight of the connecting edge  
> increases.
>  
> I think I could attempt to use a regression analysis for the second  
> hypothesis using the difference in time as the independent variable and  
> E(g)$weight as the dependent variable. But what to do (statistically)  
> and how to do it (in terms of code) with the first hypothesis?

Regression analysis works not only for a single independent variable; you could 
have multiple independent variables as well; search for “multivariate 
regression” and I’m sure that you’ll find plenty of resources on the Internet. 
Basically, you would then use the sizes of the source and target nodes as 
independent variables. In the simplest case, you could use linear regression, 
where you would end up with three coefficients (two slopes and an intercept).

> Also wouldn't be better to test both independent variables V(g)$size and
> difference in V(g)$time in the same model?

Well, you could do that as well; just take a multivariate regression technique 
and feed it with the sizes of the two endpoints and the time difference - that 
would give you three independent variables. You can still use the same 
technique as above.

T.