根据其他数据向数据添加新列

Question

我有 2 个数据框，必须通过基于 varD 进行一些计算在 data_2 中创建一个新列 data_1。 varD 的值将使用公式 (varA+pi*VarB)/VarC 计算。所以你注意到我在 varC 中只有 2 个 data_2 值。对于它们中的每一个，varD 的对应值将是平均值，即计算 5 个可能的值，然后取平均值。

data_1<- data.frame(date=c("2015-01-06 00:01:00", "2015-01-06 00:01:01","2015-01-06 00:01:02", 
                           "2015-01-06 00:01:03", "2015-01-06 00:01:04"),
                    varA=c(1,5,4,8,6),
                    VarB=c(6,88,54,698,21))

data_2<-data.frame(varC=c(0.5,1.6))

我做了data_1$newVar<-data_1$varA+pi*data_1$VarB。如何使用给定条件在我的 varD 中添加 data_2，即 varD 的第一个值是 {(1+pi*6)/0.5 +(5+pi*88)/0.5...}/5？

Answer 1

对不起，虽然它应该可以工作，但有点尴尬。

# your data
data_1<- data.frame(date=c("2015-01-06 00:01:00", "2015-01-06 00:01:01","2015-01-06 00:01:02", 
                           "2015-01-06 00:01:03", "2015-01-06 00:01:04"),
                    varA=c(1,5,4,8,6),
                    VarB=c(6,88,54,698,21))

data_2<-data.frame(varC=c(0.5,1.6))
# your calculation
data_1$newVar<-data_1$varA+pi*data_1$VarB

# safe as variable
variableC1 <- data_2[1,1]
variableC2 <- data_2[2,1]

# save your logic as variable
varD1 <- sum(data_1$newVar/variableC1)/5
varD2 <- sum(data_1$newVar/variableC2)/5

# vector for column
varD <- (c(varD1, varD2))

# add to data_2
data_2 <- cbind(varC=data_2$varC, varD)

Answer 2

你可以这样做。

tmp=matrix(0, nrow=5, ncol=2)
for (i in 1:nrow(data_2)) {
    tmp[,i]=data_1$newVar/(data_2$varC)[i]
}
varD=apply(tmp, 2, mean)
data_2[,"varD"]=varD

  varC      varD
1  0.5 1099.1043
2  1.6  343.4701

Answer 3

基础 R

# get average function
myfun <- function(x, y, z) { lapply(z, function(n) mean((x + (pi * y))/n)) }
# apply your function to data
data_2$varD <- myfun(x = data_1$varA, y = data_1$VarB, z = data_2$varC )

数据表

library('data.table')
setDT(data_2)
data_2[, varD := myfun(x = data_1$varA, y = data_1$VarB, z = varC )]    

输出：

data_2
#  varC     varD
#1:  0.5 1099.104
#2:  1.6 343.4701

数据：

data_1<- data.frame(date=c("2015-01-06 00:01:00", "2015-01-06 00:01:01","2015-01-06 00:01:02", 
                           "2015-01-06 00:01:03", "2015-01-06 00:01:04"),
                    varA=c(1,5,4,8,6),
                    VarB=c(6,88,54,698,21))

data_2<-data.frame(varC=c(0.5,1.6))