exams.forge (version 1.0.10)

toString.polynomial: 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 polynomial
toString(
  x,
  digits = TRUE,
  decreasing = FALSE,
  variable = "x",
  simplify = TRUE,
  tol = 1e-09,
  ...
)

Value

A character

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

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)