legend/plotmath/substitute problem

On 12/14/2006 5:05 PM, Philipp Pagel wrote:

My problem starts, when I want to put more than one series of data in
the plot and accordingly need one legend row per data series:

year1 = 2001
year2 = 2005
g1 = 1.9
g2 = 1.7
plot(1)
legend('top', 
legend=c(
	substitute(paste(year, ': ', gamma, '=', g), 
	list(year=year1, g=g1)),
	substitute(paste(year, ': ', gamma, '=', g), 
	list(year=year2, g=g2))
)
)

This obviously does not produce the desired result. Apparently, I am not
generating a list of expressions, as intended. So I thought, maybe R uses a
variety of the recycling rule here and tried:

The problem is that legend wants an expression, but substitute() isn't 
returning one, it's returning a call, and c(call1,call2) produces a list 
of two calls, not an expression holding two calls.  So the following 
would work, but there might be something more elegant: