Thanks for the hint with the type alias.
Using an array of projects does not help me, because I want to have an easy
way to plot any of the numbers in the
list of projects. And I don't know any easy way to convert one field of an
array of projects into a one dimensional
vector that can be plotted.
Furthermore I use the type Number because I use OpenOpt with automatic
differentiation. The numbers can also
have the type ForwardDiff.GradientNumber .
Best regards:
Uwe
On Sunday, March 13, 2016 at 3:05:31 PM UTC+1, FQ wrote:
>
> I'm not an expert on this, but instead of
>
> NumberOrVector = Union{Number, Vector}
>
> one should probably always use
>
> typealias NumberOrVector Union{Number, Vector}
>
> which makes the names equivalent statically, opposed to the =, which
> assigns a value (Union{Number,Vector}) to the variable NumberOrVector
> which could be changed later, so this is probably bad if the compiler
> tries to optimze things.
>
> Can you describe in words what you are trying to accomplish with the
> code in that gist? It looks like you implement the whole NumberOrVector
> type just so you could have multiple "Project"s in a single instance of
> "Project", which does not make sense semantically. Judging from your
> variable names, it looks like a single project has serveral parameters,
> each of which is just a single number. This is not good design. You
> could simply make 'projects' an Array{Project,1} like so:
>
> julia> type Project
> p_el_nom::Number
> rel_drum_diameter::Number
> end
>
> julia> projects = Array{Project,1}()
> 0-element Array{project,1}
>
> julia> p1 = project(1.4,3)
> project(1.4,3)
>
> julia> p2 = project(-4,99)
> project(-4,99)
>
> julia> push!(projects,p1)
> 1-element Array{project,1}:
> project(1.4,3)
>
> julia> push!(projects,p2)
> 2-element Array{project,1}:
> project(1.4,3)
> project(-4,99)
>
> julia> projects
> 2-element Array{project,1}:
> project(1.4,3)
> project(-4,99)
>
> julia> projects[2].p_el_nom
> -4
>
> The 1 in Array{Project,1} means "one-dimensional"; if it were 2 (or
> more) it would create an n-dimensional matrix, but that does not seem to
> make sense for your case.
>
> Also, you might wish to be a little more specific with your types.
> "Number" is very general, and might also be a complex number for
> instance. Judging from your variable names, AbstractFloat would probably
> be a good idea. If any of your parameters is always a whole number, you
> could also use Int for that.
>
> regards
> fq
>
> Am 13.03.2016 um 13:58 schrieb Uwe Fechner:
> > Hello,
> >
> > I need a custom type, that can hold scalars or vectors, that I can print
> > and copy.
> >
> > I created an example:
> > https://gist.github.com/ufechner7/8545f18ad6d65b80b334
> >
> > Is this good programming style?
> >
> > Is it a good idea to use a union like:
> > NumberOrVector = Union{Number, Vector}
> >
> > Is there a way to implement the copy and the push! functions in a
> > generic way, so they
> > do not need to be modified if I add fields?
> >
> > Perhaps there is also a generic way to implement the constructor:
> > Project(f::Vector)
> >
> > Any hints appreciated!
> >
> > Uwe Fechner
> >
> >
>
>
