DSM assignment part 3

## part B.3

library(mgcv)
tritiumB3 <- data[,5]
latitudeB3 <- data[,1]
longtitudeB3 <- data[,2]
salinityB3 <- data[,3]
pressureB3 <- data[,4]
longtitudeB3 <- tritium
est_add <- gam(tritiumB3~s(latitudeB3)+s(longtitudeB3) + s(salinityB3) + s(pressureB3))
par(mar = c(1,1,1,1))
plot(est_add)

lm <- lm(tritiumB3 ~ latitudeB3 + longtitudeB3 + salinityB3 + pressureB3)
summary(lm)
plot(latitudeB3, tritiumB3, xlab="latitude", ylab="'tritium")
intercept <- -2.609e-15
abline(intercept, -1.286e-17)
plot(longtitudeB3, tritiumB3, xlab="longtitude", ylab="'tritium")
abline(intercept, 1.000e+00)
plot(salinityB3, tritiumB3, xlab="salinity", ylab="'tritium")
abline(intercept, 6.856e-17)
plot(pressureB3, tritiumB3, xlab="salinity", ylab="'tritium")
abline(intercept, 1.040e-17)