f=read.csv(file.choose(),header=TRUE,sep=",")
f[is.na(f)]<-2
a<-f[,1]
b<-levels(factor(a))
k<-length(b)
for(i in 1:k){
c<-subset(f,f$LICENSEPLATENO==b[i])
c$GPS_TIME<-as.character(c$GPS_TIME)
d<-as.numeric(strptime(c$GPS_TIME,format = "%Y/%m/%d %H:%M"))
data<-sort(d)
e<-c[order(d),]
g<-length(e$EFF)
e[is.na(e$EFF)]<-0
for(j in 2:g){
if(e$EFF[j]==1&e$EFF[j-1]==0&e$EFF[j+1]==1){
print(j)
e<-e[j,]
names(e)<-NULL
write.table(e,file="C:/Users/Administrator/Desktop/b.csv",sep=',',append=TRUE)
}else{next}
}}
运行后提示Error in if (e$EFF[j] == 1 & e$EFF[j - 1] == 0 & e$EFF[j + 1] == 1) { :
参数长度为零
望高手解答
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