40->c;
21->f;
lm(b[[c]][b$V1==f] ~ b$V2[b$V1==f] + b$V3[b$V1==f]) -> m
plot(b[[c]][b$V1==f]);
points(m[[1]][[1]] + b[[2]][b$V1==f]*m[[1]][[2]] + b[[3]][b$V1==f]*m[[1]][[3]], pch=20);
m

b$V1 == 150 -> set
4->c
b$V2[set] -> va
b$V3[set] -> vb
va*vb -> vab
va*va -> vaa
vb*vb -> vbb
lm(b[[c]][set] ~ vaa + vbb + vab) -> m
plot(b[[c]][set]);
points(m[[1]][[1]] + vaa*m[[1]][[2]] + vbb*m[[1]][[3]] + vab*m[[1]][[4]], pch=20);
m

