I am trying to fill in table1 with matching val2 values of table2
我试图填写table1与table2的val2值匹配
table1$New_val2 = table2[table2$pid==table1$pid,]$val2
But I get the warning
但是我得到了警告
longer object length is not a multiple of shorter object length
which is fair enough because the table lengths are not the same.
这是公平的，因为表长度不一样。
Please kindly direct me on the correct way to do this.
请以正确的方式指导我这样做。
3 个解决方案
#1
17
merge(table1, table2[, c("pid", "col2")], by="pid")
合并（table1，table2 [，c（“pid”，“col2”）]，by =“pid”）
Add in the all.x=TRUE argument in order to keep all of the pids in table1 that don't have matches in table2.
添加all.x = TRUE参数以保持table1中table2中没有匹配项的所有pid。
You were on the right track. Here's a way using match...
你走在正确的轨道上。这是使用匹配的一种方式......
table1$val2 <- table2$val2[match(table1$pid, table2$pid)]
table1 $ val2 < - table2 $ val2 [match（table1 $ pid，table2 $ pid）]
#2
3
I am not sure if you mean this but you might use:
我不确定你是否意味着这个，但你可以使用：
newtable <- merge(table1,table2, by = "pid")
This will create a new table called newtable, with 3 columns and those values matched by the id, in this case "pid".
这将创建一个名为newtable的新表，其中包含3列，并且这些值与id匹配，在本例中为“pid”。
#3
0
I'm way late here, but in case anybody else asks the same question:
This is exactly what dplyr's inner_merge does.
我在这里已经很晚了，但万一其他人问同样的问题：这正是dplyr的inner_merge所做的。
table1.df <- dplyr::inner_merge(table1, table2, by=pid)
The by-command specifies which column should be used to match the rows.
by-command指定应使用哪个列来匹配行。
#1
17
merge(table1, table2[, c("pid", "col2")], by="pid")
合并（table1，table2 [，c（“pid”，“col2”）]，by =“pid”）
Add in the all.x=TRUE argument in order to keep all of the pids in table1 that don't have matches in table2.
添加all.x = TRUE参数以保持table1中table2中没有匹配项的所有pid。
You were on the right track. Here's a way using match...
你走在正确的轨道上。这是使用匹配的一种方式......
table1$val2 <- table2$val2[match(table1$pid, table2$pid)]
table1 $ val2 < - table2 $ val2 [match（table1 $ pid，table2 $ pid）]
#2
3
I am not sure if you mean this but you might use:
我不确定你是否意味着这个，但你可以使用：
newtable <- merge(table1,table2, by = "pid")
This will create a new table called newtable, with 3 columns and those values matched by the id, in this case "pid".
这将创建一个名为newtable的新表，其中包含3列，并且这些值与id匹配，在本例中为“pid”。
#3
0
I'm way late here, but in case anybody else asks the same question:
This is exactly what dplyr's inner_merge does.
我在这里已经很晚了，但万一其他人问同样的问题：这正是dplyr的inner_merge所做的。
table1.df <- dplyr::inner_merge(table1, table2, by=pid)
The by-command specifies which column should be used to match the rows.
by-command指定应使用哪个列来匹配行。