????merge函數(shù)的聲明:
merge(x,?y,?by?=?intersect(names(x),?names(y)),
??????by.x?=?by,?by.y?=?by,?all?=?FALSE,?all.x?=?all,?all.y?=?all,
??????sort?=?TRUE,?suffixes?=?c(".x",".y"),
??????incomparables?=?NULL,?...)????merge函數(shù)參數(shù)的說明:
????x,y:用于合并的兩個數(shù)據(jù)框
????by,by.x,by.y:指定依據(jù)哪些行合并數(shù)據(jù)框,默認(rèn)值為相同列名的列.
????all,all.x,all.y:指定x和y的行是否應(yīng)該全在輸出文件.
????sort:by指定的列是否要排序.
????suffixes:指定除by外相同列名的后綴.
????incomparables:指定by中哪些單元不進(jìn)行合并.
????例子:
w1:
NAME????SCHOOL????CLASS????ENGLISH
A????S1????10????85
B????S2????5????50
A????S1????4????90
A????S1????11????90
C????S1????1????12
w2:
NAME????SCHOOL????CLASS????MATHS????ENGLISH
A????S3????5????80????88
B????S2????5????????81
C????S1????1????55????32????按照NAME, SCHOOL, CLASS合并w1和w2:
merge(w1,?w2,?all?=?T)
??NAME?SCHOOL?CLASS?ENGLISH?MATHS
1????A?????S1?????4??????90????NA
2????A?????S1????10??????85????NA
3????A?????S1????11??????90????NA
4????A?????S3?????5??????88????80
5????B?????S2?????5??????50????NA
6????B?????S2?????5??????81????
7????C?????S1?????1??????12????NA
8????C?????S1?????1??????32????55
merge(w1,?w2,?by?=?c("NAME",?"SCHOOL",?"CLASS"),?all?=?T)
??NAME?SCHOOL?CLASS?ENGLISH.x?MATHS?ENGLISH.y
1????A?????S1?????4????????90????NA????????NA
2????A?????S1????10????????85????NA????????NA
3????A?????S1????11????????90????NA????????NA
4????A?????S3?????5????????NA????80????????88
5????B?????S2?????5????????50????????????81
6????C?????S1?????1????????12????55????????32
merge(w1,?w2,?all?=?T,?incomparables?=?"A")
Error?in?merge.data.frame(w1,?w2,?all?=?T,?incomparables?=?"A")?:
??'incomparables'?is?supported?only?for?merging?on?a?single?column
merge(w1,?w2,?all?=?T,?by?=?"NAME",?incomparables?=?"A")
??NAME?SCHOOL.x?CLASS.x?ENGLISH.x?SCHOOL.y?CLASS.y?MATHS?ENGLISH.y
1????A???????S1??????10????????85?????<NA>??????NA????NA????????NA
2????A???????S1???????4????????90?????<NA>??????NA????NA????????NA
3????A???????S1??????11????????90?????<NA>??????NA????NA????????NA
4????A?????<NA>??????NA????????NA???????S3???????5????80????????88
5????B???????S2???????5????????50???????S2???????5????????????81
6????C???????S1???????1????????12???????S1???????1????55????????32