r - How to extract top variables from regression tree and use in regression? -
so created regression tree using rpart outputs reg_tree
# show summary statistics of reg_tree summary(reg_tree) # store top variables new values topvars <- reg_tree$variable.importance # output of topvars topvars q_21fb1900 q_2b3296a0 q_0 q_fde6a01e q_7fa850ed q_323d6cee q_c6ab3657 q_eb2ad90d q_5dcb2b57 5.303283e+15 5.196871e+15 4.002239e+15 4.412505e+14 2.616730e+14 2.162128e+14 2.035465e+14 1.354927e+14 5.095959e+13 q_af2830be q_caa61b2c q_a6828865 q_99f5a0bd q_be83fe28 q_efdc29dd q_9e86aa7f q_2ea0e2aa q_5049294d 2.176437e+13 1.210118e+13 1.126591e+13 8.387189e+12 4.951978e+12 4.115929e+12 3.864235e+12 1.449853e+12 5.436949e+11 q_5ae0f0cd q_518fba14 5.436949e+11 5.412242e+11 i want extract each of these names xvar1, xvar2 , automatically put them in following model each xvar correspond column heading: lm(y_var ~ xvar1 + xvar2 + xvar3 + ... +,data).
ie
lm(y_var ~ q_21fb1900 + q_2b3296a0 + q_0 + ... +,data) how do can drop in new data sets , not worry custom changing each xvar in future?
try this:
example:
reg_tree <- rpart(kyphosis ~ age + number + start, data = kyphosis) topvars <- reg_tree$variable.importance myreg<-lm(as.formula(paste("as.numeric(kyphosis) ~ ",paste(names(topvars), collapse = " + "), sep = "")),data=kyphosis) > summary(myreg) call: lm(formula = as.formula(paste("as.numeric(kyphosis) ~ ", paste(names(topvars), collapse = " + "), sep = "")), data = kyphosis) residuals: min 1q median 3q max -0.79440 -0.22356 -0.08478 0.10205 0.84768 coefficients: estimate std. error t value pr(>|t|) (intercept) 1.2612198 0.1934124 6.521 6.61e-09 *** start -0.0307392 0.0091166 -3.372 0.00117 ** age 0.0010657 0.0006937 1.536 0.12858 number 0.0525555 0.0274522 1.914 0.05928 . --- signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 residual standard error: 0.3599 on 77 degrees of freedom multiple r-squared: 0.2575, adjusted r-squared: 0.2285 f-statistic: 8.9 on 3 , 77 df, p-value: 3.912e-05
Comments
Post a Comment