让'模型'脱离地球

Question

抱歉糟糕的头衔.不知道我应该怎么说.

我正在玩地球包,看看使用或多或少的标准指标回归神经网络信号.数据文件是1000行,当前有187列(186指标结果),最后一列中有我的目标变量.我编写的代码非常简单,现在省略了任何样本内与样本外的问题,但至少它似乎起作用:

library(earth)
MyData = read.csv("C:\\Users\\TSIT\\\\GS-Pass12.csv",header=TRUE)
x=data.frame(MyData[,1:ncol(MyData)-1])
y=MyData[,ncol(MyData)]

a = earth(x,y,nprune=5)
summary(a, digits = 2, style = "pmax")

摘要的输出看起来很合理:

summary(a, digits = 2, style = "pmax")
Call: earth(x=x, y=y, nprune=5)

y =  1.2
  - 31 * pmax(0, Percent.Difference.from.Moving.Average..C..10. -   0.096)    
  + 10 * pmax(0, 0.096 - Percent.Difference.from.Moving.Average..C..10.)    
  + 25 * pmax(0, Percent.Difference.from.Moving.Average..C..15. -  0.14) 
  - 16 * pmax(0,  0.14 - Percent.Difference.from.Moving.Average..C..15.) 

Selected 5 of 116 terms, and 2 of 185 predictors  Importance:
Percent.Difference.from.Moving.Average..C..15.,
Value.Oscillator..C..8..26..1.-unused, ... Number of terms at each
degree of interaction: 1 4 (additive model) GCV 0.083    RSS 239   
GRSq 0.66    RSq 0.66

我现在正在努力的是如何将结果模型(y)从a变为某种R变量,以便我可以使用它.有人能指出我在正确的方向吗？

提前致谢.

Answer 1

该format()功能可以使用:

R> library(earth)
R> example(earth)
[... stuff omitted ...]
R> cat(format(a), "\n")
  27.2459
  +  6.17669 * h(Girth-14)
  -  3.26623 * h(14-Girth)
  + 0.491207 * h(Height-72)
R> 

还有其他格式:

R> cat(format(a, style="pmax"), "\n")
  27.2459
  +  6.17669 * pmax(0,  Girth -     14) 
  -  3.26623 * pmax(0,     14 -  Girth) 
  + 0.491207 * pmax(0, Height -     72) 

R> cat(format(a, style="bf"), "\n")
  27.2459
  +  6.17669 * bf1
  -  3.26623 * bf2
  + 0.491207 * bf3

   bf1  h(Girth-14)
   bf2  h(14-Girth)
   bf3  h(Height-72)

R>