On 14-01-19 4:16 PM, peter dalgaard wrote:
It's not formals() that is doing you in. Rather, it is a conspiration between
two things:
(a) R always displays complex constants as x+yi, even if x is zero and (b)
there really is no way to specify complex constants with non-zero real part,
i.e. 1+2i is a sum of a real and and imaginary complex constant. You can see
the effect already at
quote(1+2i)
1 + (0+2i)
q <- quote(1+2i)
q[[1]]
`+`
q[[2]]
[1] 1
q[[3]]
[1] 0+2i
str(q)
language 1 + (0+2i)
str(q[[3]])
cplx 0+2i
Someone might want to fix this by implementing a full syntax for complex
constants, but meanwhile, I think a passable workaround could be
That might be nice to do. Not sure if it's easy or hard...
formals(test)$a <- 1+2i
args(test)
function (a = 1+2i)
NULL
test
function (a = 1+2i)
{
}
Or maybe, less sneaky
Cplx_1plus2i <- 1+2i
test <- function(a = Cplx_1plus2i){}
Less sneaky, but a tiny bit different due to scoping issues: if the
function happens to assign something to a local variable Cplx_1plus2i
before evaluating a, the local variable will be used rather than the
global one.
Duncan Murdoch
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