>
> Maybe you could use value types (
> http://julia.readthedocs.org/en/latest/manual/types/#value-types ),
> however, you need to use the latest nighly builds for that. Eg
Something very similar to the first example actually works in 0.3:
immutable Problem{S} end
> f(::Type{Problem{1}}, x) = x^2
> f(::Type{Problem{2}}, x) = sin(x)
> f(Problem{1}, 1)
>
1
> f(Problem{2}, 1)
0.8414709848078965
On Thu, Feb 19, 2015 at 4:24 AM, Tamas Papp <[email protected]> wrote:
> Hi,
>
> Maybe you could use value types (
> http://julia.readthedocs.org/en/latest/manual/types/#value-types ),
> however, you need to use the latest nighly builds for that. Eg
>
> func(::Type{Val{1}}, x) = x^2
> func(::Type{Val{2}}, x) = sin(x)
>
> func(Val{1},1) # => 1
> func(Val{2},1) # => sin(1)
>
> If you want to stick with 3.6 for now, you could create types for the
> cases.
>
> type Case1 end
> func(::Type{Case1}, x) = x^2
> type Case2 end
> func(::Type{Case2}, x) = sin(x)
>
> func(Case1, 1) # => 1
> func(Case2, 1) # => sin(1)
>
> Best,
>
> Tamas
>
> On Thu, Feb 19 2015, Devendra Ghate <[email protected]> wrote:
>
> > Hello everyone,
> >
> > Consider following function:
> >
> > ~~~
> > function funca(problem, x)
> > if problem == 1
> > return x^2;
> > elseif
> > problem == 2
> > return sin(x);
> > end
> > end
> > ~~~
> >
> > I have shown only 2 cases. However, there are around 100 cases. These
> > `if ... else` statements are being evaluated unnecessarily. If I use
> > `switch` structure then it will be faster. But I want to do away with
> > these.
> >
> > Since the arguments and their datatypes remain the same, I don't know
> > how to create multiple methods for function.
> >
> > What is the best strategy to achieve this?
> >
> > Background:
> >
> > I am trying to implement a library of ODE solvers for my students.
> >
> > $y`` + a(x)y` + b(x) = f(x) $
> >
> > Above function calculates $a(x)$ for a given problem at a specific $x_0$.
> >
> > So there should various ODE problems defined via the coefficients of
> > the derivative terms. My students will then implement various solution
> > strategies and compare their performance for these problems. So I need
> > to provide
> > them with functions `funca` `funcb` `funcf` which give the appropriate
> > coefficient depending on the problem.
>
>
