[英]Trying to create a dataframe as result of a loop
我正在嘗試創建一個循環的數據框:
variation <- seq(0.10, 3, 0.5)
for (i in seq_along(variation)) {
x <- iris %>% mutate(newLength = Sepal.Length + variation[i])
newSum <- x %>% summarise(newSum = sum(newLength))
oldSum <- iris %>% summarise(oldSum = sum(Sepal.Length))
df <- cbind(variation[i], oldSum, newSum)
z <- rbind(df)
print(z)
}
我得到的輸出是:
variation[i] oldSum newSum
1 0.1 876.5 891.5
variation[i] oldSum newSum
1 0.6 876.5 966.5
variation[i] oldSum newSum
1 1.1 876.5 1041.5
variation[i] oldSum newSum
1 1.6 876.5 1116.5
variation[i] oldSum newSum
1 2.1 876.5 1191.5
variation[i] oldSum newSum
1 2.6 876.5 1266.5
我想要的輸出是:
variation[i] oldSum newSum
0.1 876.5 891.5
0.6 876.5 966.5
1.1 876.5 1041.5
1.6 876.5 1116.5
2.1 876.5 1191.5
2.6 876.5 1266.5
我究竟做錯了什么?
rbind()將多行綁定在一起。 如果只給它一個df,它將僅返回該數據幀。 嘗試rbind(z,df)將新的DF附加到舊的z。
variation <- seq(0.10, 3, 0.5)
for (i in seq_along(variation)) {
x <- iris %>%
mutate(newLength = Sepal.Length + variation[i])
newSum <- x %>%
summarise(newSum = sum(newLength))
oldSum <- iris %>%
summarise(oldSum = sum(Sepal.Length))
df <- cbind(variation[i], oldSum, newSum)
z <- rbind(z,df)
print(z)
}
請注意,z不會被清除,因此您可能希望在開始循環之前對其進行初始化。 z = NULL之類的東西可以確保它為空。
您應該嘗試使用outer
向量函數來進行分析的主要復雜部分:
data.frame(
variation,
oldSum=sum(iris$Sepal.Length),
newSum=colSums(outer(iris$Sepal.Length, variation, FUN=`+`))
)
# variation oldSum newSum
#1 0.1 876.5 891.5
#2 0.6 876.5 966.5
#3 1.1 876.5 1041.5
#4 1.6 876.5 1116.5
#5 2.1 876.5 1191.5
#6 2.6 876.5 1266.5
正如@Frank指出的那樣,您可以進一步簡化/加快此過程:
sum.sl <- sum(iris$Sepal.Length)
data.frame(
variation,
oldSum=sum.sl,
newSum=sum.sl + length(iris$Sepal.Length)*variation
)
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.