在 r 中，您将如何编码以根据两个分箱值的组合获取值？

如何解决在 r 中，您将如何编码以根据两个分箱值的组合获取值？

我想计算温度和降水值的每种可能组合的中值流行密度。例如，以下地点的人口密度：

Mean annual temp of 4 to 6 C and 500 to 510 mm precip
Mean annual temp of 4 to 6 C and 510 to 520 mm precip
Mean annual temp of 4 to 6 C and 520 to 530 mm precip
Mean annual temp of 6 to 8 C and 500 to 510 mm precip
Mean annual temp of 6 to 8 C and 510 to 520 mm precip
Mean annual temp of 6 to 8 C and 520 to 530 mm precip and so on...

我的数据是这样的：

 Pp    Pmm    t  
21.18  83.81  31.24 
14.81 174.49  30.80 
14.81 129.59  30.72 
52.04 230.53  30.59 
8.56  206.69  30.57 
5.06  194.85  30.55 

到目前为止，我只对这些数据进行了分箱：使用以下代码：

# MAKING precipitation BINS
# set up cut-off values
breaks <- seq(0,7010,10)
# specify interval/bin labels
tags <- paste(seq(0,7000,10),"-",seq(10,sep="")
# bucketing values into bins
group_tags <- cut(test$Pmm,breaks=breaks,include.lowest=TRUE,right=TRUE,labels=tags)
# inspect bins
summary(group_tags)

# Temperature Bins
# set up cut-off values 
breaks1<- seq(0,32,2)
# specify interval/bin labels
tags1 <- paste(seq(0,30,2),seq(2,sep="")
# bucketing values into bins
group_tags1 <- cut(test$t,breaks=breaks1,right=FALSE,labels=tags1)
# inspect bins
summary(group_tags1)

我尝试了四个循环，但无法使它们工作。有什么想法吗？

解决方法

你可以试试：

breaks <- seq(0,7010,10)
tags <- paste0(seq(0,7000,10),"-",seq(10,10))
test$group_tags <- cut(test$Pmm,breaks=breaks,include.lowest=TRUE,right=TRUE,labels=tags)


breaks1<- seq(0,32,2)
tags1 <- paste0(seq(0,30,2),seq(2,2))
test$group_tags1 <- cut(test$t,breaks=breaks1,right=FALSE,labels=tags1)

#Create all possible combination of group_tags and group_tags1
all_combns <- expand.grid(group1 = test$group_tags,group2 = test$group_tags1)

#For each combination calculate average value of `Pp`.
do.call(rbind,Map(function(x,y) data.frame(Pmm_group = x,temp_group = y,average = mean(test$Pp[test$group_tags == x & test$group_tags1 == y])),all_combns$group1,all_combns$group2)) -> result

result