I'm having issues doing a multivariate Granger's causal test. I'll like to check if conditioning a third variable affects the results of a causal test. Here's one sample for a single dependent and independent variable based on an earlier question I asked and was answered by @Alex
Granger's causality test by column
library(lmtest)
M1<- matrix( c(2,3, 1, 4, 3, 3, 1,1, 5, 7), nrow=5, ncol=2)
M2<- matrix( c(7,3, 6, 9, 1, 2, 1,2, 8, 1), nrow=5, ncol=2)
M3<- matrix( c(1, 3, 1,5, 7,3, 1, 3, 3, 4), nrow=5, ncol=2)
For example, the equation for a conditioned linear regression will be
formula = y ~ w + x * z
How do I carry out this test as a function of a third or fourth variable please?