toString.polynomial: Text Representation of a Polynomial

In exams.forge: Support for Compiling Examination Tasks using the 'exams' Package

Text Representation of a Polynomial

Description

Creates a text representation for a polynomial, in the following scenarios:

• if digits is TRUE then as.character(.) is used

• if digits is FALSE then ./. is used

• if digits is numeric then as.character(round(., digits)) is used

Usage

## S3 method for class 'polynomial'
toString(
  x,
  digits = TRUE,
  decreasing = FALSE,
  variable = "x",
  simplify = TRUE,
  tol = 1e-09,
  ...
)

Arguments

x	polynomial: vector of coefficients (first is intercept)
digits	numeric or logical: how to convert to text (default: NA)
decreasing	logical: order of the terms by increasing or decreasing powers (default: FALSE)
variable	character: name of the variable used (default: "x")
simplify	logical: should the polynomial representation be simplified (default: TRUE)
tol	numeric: tolerance (default: 1e-9). A negative value will keep zeros and ones too, but: If a coefficient is smaller than tol then zero terms are not kept. If a absolute value of coefficient minus one is smaller than tol then coefficient is not kept
...	unused parameters

Value

A character

Examples

p <- polynomial(c(-1,0,2)/3)
toString(p, 4)
toString(p, FALSE)
toString(p, TRUE)
toString(p, variable="z")
toString(p, decreasing=TRUE)
p <- polynomial(c(0,1,2)/3)
toString(p)
toString(p, tol=-1)

exams.forge documentation built on Aug. 21, 2025, 5:41 p.m.