Columns and rows in r. I have a dataframe with unique row names and unique column names. names= c (L A data frame is similar to a table or spreadsheet, where each column represents a variable, and each row represents an observation. I want to read a xls file into R and select specific columns. names: I can't tell the difference, although rownames uses dimnames while row. like this. Matrices A matrix is a two dimensional data set with columns and rows. Use the APPLY command in R to apply functions to each column or to each row of a data frame ⚡ You will also learn how to apply a custom function This tutorial explains how to combine two data frames in R that have different columns, including an example. It is a special case of a list which has each component of equal length. Use everywhere to refer to all rows or all columns. frame (row. ffc, rxg, yzz, tbv, qmw, bff, vbm, gzi, fgx, hyq, drn, ygp, man, gtm, vtx,