factor.as.numeric: Handle Numbers Stored as Factors

In ejanalysis/analyze.stuff: Miscellaneous Tools for Analyzing Data in Rows and Columns

Handle Numbers Stored as Factors

Description

Try to convert back to numeric any numbers stored as factors, e.g., in a data.frame that did not use stringsAsFactors.

Usage

factor.as.numeric(x, stringsAsFactors = TRUE)

Arguments

x	Data.frame or vector, required. (If matrix, it is returned unaltered as a matrix).
stringsAsFactors	Logical, TRUE by default, in which case a factor vector or col that has character elements, and thus cannot be coerced to numeric without creating NA values, is left as a factor. If FALSE, such a vector or col is converted to character class.

Details

Uses as.numeric(as.character(x)) on the factor cols or vector, but if there are both numbers and characters, it leaves it as factor, not numeric (which would put NA values in place of character elements). NOTE: ** Not optimized for speed yet, so it is slow.

Value

Returns a data.frame or vector, same shape as x (or matrix if given a matrix). Any column that was integer or numeric is returned as numeric.
Any character column or vector is returned as numeric if it could be coerced to numeric without creating any NA values because it has only numbers stored as text.
Logical is returned as logical.
When stringsAsFactors is TRUE, factor is returned as factor if it has any text that cannot be coerced to non-NA numeric.
When stringsAsFactors is FALSE, factor is returned as character if it has any text that cannot be coerced to non-NA numeric.

See Also

as.vector(), factor(), data.table::data.table(), matrix()

Examples

a=factor(c(2,3,5)); b=factor(c('2', '3', '5')); c=factor(c('two','three','five'))
d=factor(c(2,'3','5')); e=factor(c(2,'three','five')); f=factor(c('2','three','5'))
g=factor(c(2,'3','five')); h=factor(c(NA, 3, 'five')); i=1:3;
j=rep('nonfactor',3); k=c(1,2,'text'); l=c(TRUE, FALSE, TRUE); m=c('2','3','5')
x=data.frame(a,b,c,d,e,f,g,h,i,j,k,l,m, stringsAsFactors=FALSE)
cat('\n')
cat('\n'); x; cat('\n'); cat('\n')
z=factor.as.numeric(x)
cat('\n'); z
cat('\n'); str(x)
cat('\n'); str(z);
cat('\n'); str( factor.as.numeric(x, stringsAsFactors=FALSE) )
for (i in 1:length(x)) {out<-factor.as.numeric(x[,i]);cat(class(out), out,'\n') }
for (i in 1:length(x)) {
  out<-factor.as.numeric(x[,i], stringsAsFactors = FALSE)
  cat(class(out), out,'\n')
}

ejanalysis/analyze.stuff documentation built on April 2, 2024, 10:10 a.m.