I'm wondering if someone can assist me in extracting GLM relativities when using splines? I have searched CV and cannot find an easily understandable answer.
Here is some code in R (my apologies as I do not know python).
#load segemented package for plant data library(segmented) #load splines package library(splines) #get data data <- data("plant") #run GLM and get summary glm_model <- glm(y ~ time, data = plant) summary(glm_model) #add spline and get summary glm_model2 <- glm(y ~ bs(time, degree = 1, knots = c(366.5)), data = plant) summary(glm_model2)
Here is the summary from the splines model.
glm(formula = y ~ bs(time, degree = 1, knots = c(366.5)), data = plant)
Min 1Q Median 3Q Max
-0.37187 -0.15317 0.05867 0.12065 0.23452
Error t value
(Intercept) 0.36133 0.04236 8.529 1.63e-13 ***
bs(time, degree = 1, knots = c(366.5))1 0.48467 0.05794 8.365 3.71e-13 ***
bs(time, degree = 1, knots = c(366.5))2 0.42415 0.05469 7.756 7.59e-12 ***
How would I convert the polynomial coeefficients in the spline summary to actual GLM relativities? It doesn't need to be in
R if someone can explain the math but if anyone has an
R example, that would be great!