R merge（）得到了令人惊讶的结果_R

R merge（）得到了令人惊讶的结果

R merge（）得到了令人惊讶的结果,r,R,A有A、b、c、d列 B有a、B、c、e列 merged = merge(A,B,by = c("a","b","c"), all.x = TRUE, sort = FALSE) A$difference = merged$d - A$d sum(A$difference) # <- this is unequal 0 什么是d和d.聚合对象？你能提供A和B的示例数据吗？这讨论了如何询问有关SO的问题：请重新阅读提供的链接@G.Grothendieck，可能还有此链接，具体针对R:。你的

A有A、b、c、d列 B有a、B、c、e列

merged = merge(A,B,by = c("a","b","c"), all.x = TRUE, sort = FALSE)
A$difference = merged$d - A$d
sum(A$difference) # <- this is unequal 0

什么是d和d.聚合对象？你能提供A和B的示例数据吗？这讨论了如何询问有关SO的问题：请重新阅读提供的链接@G.Grothendieck，可能还有此链接，具体针对R:。你的问题仍然无法重现，因为我们不知道d中是什么或d中是什么。

A = d[c("OpTyp","DeltaOffset","Size","Duration")]
B = d.aggregated[c("OpTyp","DeltaOffset","Size","mean_Duration")]
merged = merge(A,B,by = c("OpTyp","DeltaOffset","Size"), all.x = TRUE, sort = FALSE)

merged$difference = A$Duration - merged$Duration
sum(merged$difference)