Expand {lazy.symbolic}

R Documentation

Expand Expressions by Distributing a Multiplicative Factor

Description

Expand Expressions by Distributing a Multiplicative Factor

Usage

Expand(expr, all = 0, method = 1:2, simplify = 1, verify = 1, debug = 0)

Arguments

expr	A vector or list of symbolic expressions
all	= 1 to apply Expand repeatedly
method	= 1 to expand a*(...) = 2 to expand (...)*a
simplify	= 0 to skip the simplification of the result
verify	= 0 not to check the result by is_valid
debug	= 1 to print intermediate result

Details

This function expands a single occurence of
a*(b+c) and (a+b)*c
to
a*b+a*c and a*c+b*c, resp.,
where a is a single multiplicative factor and b and c are additive terms.

Matrix multiplications such as %*% and %@% can be used.

Repeated use may expand it further.

Value

Expanded expression

Examples

Expand(c("a*(b+c)","-(b+c)*a"))
Expand(c("a/(b*c)","-(b*c)/a"))

Expand("(a+b)*(F(x)-G(y))")
Expand(.Last.value)

Expand("-a*(b-c)*(d+e)")
Expand(.Last.value)

Expand( "((+a*(b-c*d)*e+f)*g)*h - (((+a*b-c*d)*e+f)*g)*h" )
Expand(.Last.value)

Expand("-t(A)%*%(B-C)%*%D")

Expand("-inv(A)%*%(A-B)")
Expand("-inv(A)%*%(A-B)", simplify=0)

Expand("-(A-B)%*%(C-D)+E")
Expand("-(A-B)%*%(C-D)+E", all=1)

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