y_eval: Evaluate a yacas expression

In Ryacas: R Interface to the 'Yacas' Computer Algebra System

Evaluate a yacas expression

Description

Evaluate a yacas expression by replacing variables with values as for the given list.

Usage

y_eval(expr, ..., as.r = FALSE)

Arguments

expr	a valid yacas expression
...	a list of assignements (see example)
as.r	if TRUE, then the expression is evaluated as R (if any variable to be substituted in the expression is a vector, then a vector is returned). If it is FALSE (default), a yacc expression is returned, replacing scalar variables.

Examples

# Evaluate as yacas object
eq <- ysym("2*y+x^2+2*x-3")
y_eval(eq, x=3, y=2)

# Evaluate as R expression:
y_eval(eq, x=3, y=2, as.r=TRUE)
# This allows to use vectors:
y_eval(eq, x=1:10, y=2, as.r=TRUE)
# and to plot functions:
curve(y_eval(eq, x=x, y=2, as.r=TRUE), xlim=c(0,10))

Ryacas documentation built on Jan. 17, 2023, 1:11 a.m.