erf {VGAM} | R Documentation |
Error Function, and variants
Description
Computes the error function, or its inverse, based on the normal distribution. Also computes the complement of the error function, or its inverse,
Usage
erf(x, inverse = FALSE)
erfc(x, inverse = FALSE)
Arguments
x |
Numeric. |
inverse |
Logical. Of length 1. |
Details
is defined as
so that it is closely related to pnorm
.
The inverse function is defined for in
.
Value
Returns the value of the function evaluated at x
.
Note
Some authors omit the term from the
definition of
. Although defined for complex
arguments, this function only works for real arguments.
The complementary error function is defined
as
, and is implemented by
erfc
.
Its inverse function is defined for in
.
Author(s)
T. W. Yee
References
Abramowitz, M. and Stegun, I. A. (1972). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, New York: Dover Publications Inc.
See Also
Examples
## Not run:
curve(erf, -3, 3, col = "orange", ylab = "", las = 1)
curve(pnorm, -3, 3, add = TRUE, col = "blue", lty = "dotted", lwd = 2)
abline(v = 0, h = 0, lty = "dashed")
legend("topleft", c("erf(x)", "pnorm(x)"), col = c("orange", "blue"),
lty = c("solid", "dotted"), lwd = 1:2)
## End(Not run)