Nothing
###########################################################################
#
# checks a single number to see if it's negative. correctans may be null in
# this context, as it has no meaning.
#
###########################################################################
grade.negative <- function(correctans=NULL, studentans, tolerance=0.01,
useeval=TRUE, usena=FALSE, useinf=FALSE,
quiet=TRUE) {
stopifnot(grade.allnotnull(studentans, tolerance, useeval, usena, useinf))
tol.num <- grade.gettolerance(tolerance)
if (is.null(tol.num)) return(FALSE)
if (usena) {
warning("usena is not used in grade.negative, setting to FALSE")
usena <- FALSE
}
#################################################################
# simply convert studentans to a number, then pass it off to
# grade.orderedset
sans <- grade.parse(studentans, useeval, usena, useinf, quiet)
if (is.null(sans)) return(FALSE)
if (length(sans) != 1) return(FALSE)
return( sans < -tol.num )
}
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