Declaration of the Merge function:
Merge (x, y, by = intersect (names (x), names (y)), by.x = by, By.y = by, all = FALSE, all.x = all, All.y = all, sor t = TRUE, suffixes = C (". X", ". Y"), incomparables = NULL, ...)
Description of the merge function parameter:
X, y: Two data frames for merging
BY,BY.X,BY.Y: Specifies which rows are to be combined with the data frame, with the default value being the column with the same column name.
ALL,ALL.X,ALL.Y: Specifies whether the rows of x and y should be all in the output file.
Sort:by whether the specified column is to be sorted.
Suffixes: Specifies the suffix of the same column name, except by.
Incomparables: Specifies which cells in by are not merged.
Example:
w1:name school CLASS ENGLISHA S1 10 85B S2 5 50A S1 4 90A S1 11 90C S1 1 12w2:NAME SCHOOL CLASS MATHS ENGLISHA S3 5 80 88B S2 5 89 81C S1 1 55 32
Merge W1 and W2 by name, SCHOOL, class:
Merge (W1, w2, all = t) &NBSP;&NBSP;NAME&NBSP;SCHOOL&NBSP;CLASS&NBSP;ENGLISH&NBSP;MATHS1 A S1 4 90 NA2 A S1 10 85 na3 a S1 11 90 NA4 A S3 5 88 805 B S2 5 50 NA6 B S2 5 81 897 c s1 1 12 NA8 C s1 1 32 55merge ( W1, w2, by = c ("NAME", "SCHOOL", "CLASS"), all = t) name school class english.x maths english.y1 a S1 4 90 NA NA2 A S1 10 85 NA NA3 A s1 11 90 na NA4 A S3 5 NA 80 885 B S2 5 50 89 816 C S1 1 12 55 32merge (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 columnmerge (w1, w2, all = t, by = "NAME", incomparables = "A") NAME SCHOOL.x CLASS.x ENGLISH.x SCHOOL.y CLASS.y MATHS ENGLISH.y1 A S1 10 85 <NA> na na na2 a S1 4 90 <na> na NA NA3 A s1 11 90 <NA> NA NA NA4 A <NA> NA NA S3 5 80 885 B S2 5 50 S2 5 89 816 c s1 1 12 s1 1 55 32
An explanation of the merge of R language