R: Grade Intervals

grade.interval {grade}

R Documentation

Grade Intervals

Description

Checks a students interval against a correct one.

Usage

grade.interval(correctans, studentans, tolerance=0.01, useeval=TRUE, 
               usena=FALSE, useinf=FALSE, quiet=TRUE)

Arguments

`correctans`	a vector of type `numeric` or a `string`
`studentans`	a vector of type `numeric` or a `string`
`tolerance`	a `string` or `numeric` representing the accepted component wise tolerance
`useeval`	`TRUE` or `FALSE` indicates whether or not to use 'eval' on strings
`usena`	`usena` is ignored in `grade.interval`. Setting to `TRUE` results in a warning message.
`useinf`	`TRUE` or `FALSE` indicating whether or not `Inf` and `-Inf` are accepted values
`quiet`	`TRUE` or `FALSE`. If `TRUE` there are more warning messages when checks fail. Can be helpful for debugging.

Details

usena is ignored in this function. If set to true, grade.interval sets it back to false and produces a warning message. grade.interval expects correctans to be a vector of length 2, if not it errors out. If correctans is in reverse order and quiet=FALSE, grade.interval issues a warning, but continues grading.

Value

TRUE or FALSE indicating match success or failure respectively. FALSE is also returned if studentans does not look like an interval.

Note

The grade main page contains a discussion of the common parameters correctans, studentans, useeval, usena, useinf, quiet.

Examples

grade.interval(c(1,2), "[1,2]") # TRUE
grade.interval(c(1,2), "[1.1,2]", tolerance=".01") # FALSE

grade.interval(c(1,pi), "(1,3.142)", tolerance=".001") # TRUE

[Package grade version 0.2-1 Index]