Hello all,
*
*
I'm having some difficulty, and I think the problem is with how I'm using
append() nested inside a for loop. The data are:
y,x
237537.61,873
5007.148438,227
17705.77306,400
12396.64369,427
228703.4021,1173
350181.9752,1538
59967.79376,630
140322.7774,710
42650.07251,630
5382.858702,264
34405.82429,637
92261.34614,980
144927.1713,1094
362998.7355,1420
203313.6442,1070
168861.649,930
214306.5266,1040
201804.5193,1000
108426.1988,820
181651.8748,980
53675.45849,775
43068.82972,563
92393.35158,805
93305.0618,740
107308.4761,840
139056.5446,775
15411.81924,420
16104.80991,390
25629.07578,502
37121.23438,461
29711.42749,565
33400.49145,510
and the code is:
xy<-read.csv(xy.csv)
x<-xy$x
y<-xy$y
cross.val.error.temp<-numeric(0)
b<-c(1:length(x))
for(i in b){
frame.val.temp<-data.frame(x,y)
frame.val<-frame.val.temp[-i,]
yt<-frame.val$y
xt<-frame.val$x
temppow.val<-lm(log(yt)~log(xt))
tempint.val<-summary(temppow.val)$coefficients[1,1] #intercept of power
function
tempslope.val<-summary(temppow.val)$coefficients[2,1]
nls.model.val<-nls(yt~exp(intercept)*((xt)^slope),
start=list(intercept=tempint.val, slope=tempslope.val))
prediction.cross.val<-((exp(intercept.nls))*((x[i])^slope.nls))
value.temp<-(prediction.cross.val-y[i])/y[i]
cross.val.error<-append(cross.val.error.temp,value.temp)
cross.val.error
print(cross.val.error)
}
cross.val.error
print() shows the values that I'm looking for, but I must be doing
something wrong with append because the call to cross.val.error just
returns the last value that the for loop returns. Would anyone be willing
to show me how to correct my mistake?
As an aside, if anyone cares to explain how to make this work using lapply
instead of a for loop, I'm very interested.
Many thanks for looking.
*Ben Caldwell*
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
