FillIn {DataCombine}

A function for filling in missing values of a variable from one data frame with the values from another variable.

Description

FillIn uses values of a variable from one data set to fill in missing values in another.

Usage

FillIn(D1, D2, Var1, Var2, KeyVar = c("iso2c", "year"),
  allow.cartesian = FALSE, KeepD2Vars = FALSE)

Arguments

D1

the data frame with the variable you would like to fill in.

D2

the data frame with the variable you would like to use to fill in D1.

Var1

a character string of the name of the variable in D1 you want to fill in.

Var2

an optional character string of variable name in D2 that you would like to use to fill in. Note: must be of the same class as Var1.

KeyVar

a character vector of variable names that are shared by D1 and D2 that can be used to join the data frames.

allow.cartesian

logical. See the data.table documentation for more details.

KeepD2Vars

logical, indicating whether or not to keep the variables from D2 in the output data frame. The default is KeepD2Vars = FALSE. Hint: avoid having variables in your D2 data frame that share names with variables in D1 other than the KeyVars

Examples

# Create data set with missing values
naDF <- data.frame(a = sample(c(1,2), 100, rep = TRUE),
                   b = sample(c(3,4), 100, rep = TRUE),
                   fNA = sample(c(100, 200, 300, 400, NA), 100, rep = TRUE))

# Created full data set
fillDF <- data.frame(a = c(1, 2, 1, 2),
                     b = c(3, 3, 4, 4),
                     j = c(5, 5, 5, 5),
                     fFull = c(100, 200, 300, 400))

# Fill in missing f's from naDF with values from fillDF
FilledInData <- FillIn(naDF, fillDF, Var1 = "fNA",
                       Var2 = "fFull", KeyVar = c("a", "b"))