Message-ID: <CAFEqCdw8AdN+hybrC9McVnA2T_3afHpwj-1T_PurnWkHEjsBow@mail.gmail.com>
Date: 2013-12-20T16:15:01Z
From: Greg Snow
Subject: A function which is a sum of other functions...
In-Reply-To: <8F1C96F7-DBB7-4C6D-A998-E793A529F955@gmail.com>
My first thought was to use Reduce, but I think for this case that is
a bit of overkill. You can have a vector or list of functions and
just use sapply/lapply on the list of functions then sum the result.
A quick example:
> funs <- c(sin,cos,tan)
> sapply( funs, function(f) f(pi/6) )
[1] 0.5000000 0.8660254 0.5773503
> sum(sapply( funs, function(f) f(pi/6) ))
[1] 1.943376
Just wrap the above in a function with whatever options you want to
use. If you need the functions to return vectors (of the same length)
then you can still use sapply, but use rowSums, colSums, or apply on
the result instead of sum.
On Thu, Dec 19, 2013 at 12:05 PM, Onur Uncu <onuruncu at gmail.com> wrote:
>
> Dear R Users
>
> I have a list of functions. Each function in the list is a function of single variable. I would like to create a function (of one variable) which represents the sum of all the functions in the list. So, if the functions in my list are f1(x),..,f5(x) then I would like a new function f(x)=f1(x)+f2(x)+...f5(x)
>
> Appreciate any suggestions on how to do this.
>
> I need the above f(x) function because I would like to minimise it with respect to x using the nlm function.
>
> Thanks.
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--
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com