R匹配数据帧不同行中的字符串
我有一个包含条件列及其值的数据框,还有一个只包含条件的数据框,我想通过匹配条件来提取它们的值R匹配数据帧不同行中的字符串,r,dataframe,match,lapply,R,Dataframe,Match,Lapply,我有一个包含条件列及其值的数据框,还有一个只包含条件的数据框,我想通过匹配条件来提取它们的值 df1: Name Style Price Style Price Style Price Gary A 100 AB 300 B 200 Johnson AB 200 B 700 A 300 Marsha AC 300 C 500
df1:
Name Style Price Style Price Style Price
Gary A 100 AB 300 B 200
Johnson AB 200 B 700 A 300
Marsha AC 300 C 500 A 400
Watson A 400 B 200 AB 500
Emma C 500 B 100 BC 600
df1 = structure(list(Name = c("Gary", "Johnson", "Marsha", "Watson",
"Emma"), Style = c("A", "AB", "AC", "A", "C"), Price = c(100L,
200L, 300L, 400L, 500L), Style.1 = c("AB", "B", "C", "B", "B"
), Price.1 = c(300L, 700L, 500L, 200L, 100L), Style.2 = c("B",
"A", "A", "AB", "BC"), Price.2 = c(200L, 300L, 400L, 500L, 600L
)), .Names = c("Name", "Style", "Price", "Style.1", "Price.1",
"Style.2", "Price.2"), class = "data.frame", row.names = c(NA,
-5L))
df2:
Name Style
Gary AB
Johnson A
Marsha C
Watson B
Emma BC
df2 = structure(list(Name = c("Gary", "Johnson", "Marsha", "Watson",
"Emma"), Style = c("AB", "A", "C", "B", "BC")), .Names = c("Name",
"Style"), class = "data.frame", row.names = c(NA, -5L))
desired output:
Name Style Price
Gary AB 300
Johnson A 300
Marsha C 500
Watson B 200
Emma BC 600
当条件在不同的列中时,我不知道如何匹配它们。感谢您的帮助。我们可以使用
data.table
中的melt
(可以使用多个度量columnsn,然后在的“Name”和“Style”列上与第二个数据集('df2')进行联接
library(data.table)
melt(setDT(df1), measure = patterns("Style", "Price"),
value.name = c("Style", "Price"))[df2, on = c("Name", "Style")][, variable := NULL][]
# Name Style Price
#1: Gary AB 300
#2: Johnson A 300
#3: Marsha C 500
#4: Watson B 200
#5: Emma BC 600
很抱歉,如果名称不同,例如样式、图案、格式,是否将所有名称添加到value.name中?对吗?@PeterChung您的意思是style
,style
等?在这种情况下,measure=patterns([Ss]tyle”,“Price”),
我的意思是标题应该是样式价格模式价格格式价格,所以measure=patterns(“Style”、“Price”、“Pattern”、“Format”)@PeterChung如果您有4个样式的列,那么您必须指定这些样式,那么值名称如何?