crunch (version 1.20.0)

makeWeight: Generate a weight variable

Description

This function allows you to generate a weight variable by supplying a set of categorical variables and the target distribution for each of the variables' categories. Weights are computed by iteratively 'raking' conditional 'cells' to the provided marginal targets.

Usage

makeWeight(..., name)

Arguments

...

A series of expressions of the form variable ~ target_weights. The variable must be a categorical Crunch variable, and the target weights must be a numeric vector whose length should be equal to the number of categories contained in the variable, and whose sum is equal to 100 or 1. If you supply fewer target weights than there are categories makeWeight will pad the target weight vector with 0s.

name

The name of the resulting variable

Value

A crunch VariableDefinition() of the weight variable

Details

For instance, if you wanted to create a weight variable which equally weighted four categories stored in ds$var you would call ds$weight1 <- makeWeight(ds$var ~ c(25, 25, 25, 25), name = "weight1"). Note that makeWeight returns a VariableDefinition, an expression that when assigned into your Dataset becomes a derived variable. This does not on its own set the new variable as "the weight" for your dataset. To set that attribute, use weight(). Alternatively, you can also create the variable and set the weight attribute in one step with weight(ds) <- makeWeight(ds$var ~ c(25, 25, 25, 25), name = "weight1").

See Also

weight<-(); settings() for the "default weight" for other dataset viewers.

Examples

# NOT RUN {
mtcars$cyl <- as.factor(mtcars$cyl)
mtcars$gear <- as.factor(mtcars$gear)
ds <- newDataset(mtcars)
# Create a new "raked" variable
ds$weight <- makeWeight(ds$cyl ~ c(30, 30, 40, 0),
    ds$gear ~ c(20, 20, 60, 0), name = "weight")
summary(ds$weight)
# ds$weight is not "the weight" for the dataset unless you set it:
weight(ds) <- ds$weight
# Or, you can create the variable and set as weight in one step:
weight(ds) <-  makeWeight(ds$var ~ c(25, 25, 25, 25), name = "weight2")
# }