Create px classification from a data frame.
px_classification_from_df(name, prestext, domain, df)
A classification object
Optional. Name of the classification.
Optional. Presentation text.
Optional. Character vector with domain names. Used to link to PX-file.
Optional. A data frame with required column 'valuecode' and optional column 'valuetext', if the codes have texts. Each additional column represents an aggregation. The column name is the name of the aggregation. If the column type is character the aggregation levels will be sorted alphabetically; use factors to control the ordering.