if (has_sympy()) {
X1 <- matrix_(paste0("x_",c(1,1,1,1, 2,2,2,2, 3,4,3,4)), nrow = 4)
X1
colspan(X1)
do_la(X1, "columnspace")
rankMatrix_(X1)
X2 <- matrix_(paste0("x_",c(1,1,1,1, 0,0,2,2, 3,4,3,4)), nrow = 4)
X2
colspan(X2)
do_la(X2, "columnspace")
rankMatrix_(X2)
}
#> c: 3