multimerge: Merge multiple dataframe by common columns.
In vapniks/mergeutils: Functions to aid merging and checking disparate data

Description Usage Arguments Details Value Author(s)

Merge multiple dataframe by common columns.

1	multimerge(data, by = NULL, all = NULL, suffixes = NULL)

`data`	a list of dataframes to merge.
`by`	a list of vectors each of which contains column names/numbers to be used for matching rows of the corresponding dataframe in 'data'. Each of these vectors should be the same length. Final vector will be recycled to fill in missing vectors. If this argument is left as NULL then all common column names will be used for matching.
`all`	(optional) list of vectors/NULL values, each indicating which rows of the corresponding dataframe in 'data' to keep. See details below.
`suffixes`	(optional) list or vector of suffixes (one for each dataframe) to be appended to clashing column names in order to indicate the original dataframe.

Given a list of dataframes, and a list of vectors each of which contains the same number column names/numbers, merge the dataframes by matching on the corresponding columns. The 'by' argument specifies, for each dataframe, which columns to use for matching - it should be a list of numeric or character vectors. If there are not enough vectors in 'by' to cover all the dataframes in 'data' then the final vector of 'by' will be recycled to cover missing specifications.

The optional 'all' argument is a list which can be used to specify for each dataframe which rows to keep. If the i'th element of 'all' is NULL (default) then all rows of the i'th dataframe will be included in the results. Otherwise the i'th element of 'all' can be a vector of integers. In this case a row of the i'th dataframe will only be included if it is matched in all of the dataframes corresponding to positive integers, or at least one of the dataframes corresponding to negative integers in the vector. For example if all[[3]]==c(1,2,-4,-5) then a row of the 3rd dataframe will only be included in the results if it is matched in both the 1st & 2nd dataframes or in the 4th or 5th dataframes.

To avoid column name clashes, the corresponding dataframe indices will be appended to the names of any columns in the results that would otherwise clash. Alternatively suffixes can be specified in the 'suffixes' argument, which should be a list of strings.

A single dataframe containing the merged data.

Ben Veal

vapniks/mergeutils documentation built on May 3, 2019, 4:33 p.m.