Broadcasting a function with qualifiers

New to Julia
1

I’m trying to apply eigs over an array of matrices using broadcast. The thing is I want to apply eigs with certain qualifiers such as: eigs(A;nev=6,which=:SM,sigma=0.01).
The general syntax for broadcast is however: broadcast(f,array). How do I use broadcast in my case? or is there another alternative?

2

What’s the problem of using

eigs.(arrayOfMatrices;nev=6,which=:SM,sigma=0.01) ?

(note the dot)

3 Likes
3

This discussion made me wonder how the dot deals with kwargs, because I always thought it lowered straightforwardly to broadcast. That’s not the case.

The dot notation in conjuction with kwargs creates a more involved broadcasted expression

julia> Meta.@lower f.([1,2];a=2)
:($(Expr(:thunk, CodeInfo(
    @ none within `top-level scope'
1 ─ %1 = Base.vect(1, 2)
│   %2 = Base.broadcasted_kwsyntax
│   %3 = Core.tuple(:a)
│   %4 = Core.apply_type(Core.NamedTuple, %3)
│   %5 = Core.tuple(2)
│   %6 = (%4)(%5)
│   %7 = Core.kwfunc(%2)
│   %8 = (%7)(%6, %2, f, %1)
│   %9 = Base.materialize(%8)
└──      return %9
))))

help?> Base.broadcasted_kwsyntax
  No documentation found.

  Base.Broadcast.broadcasted_kwsyntax is a Function.

  # 1 method for generic function "broadcasted_kwsyntax":
  [1] broadcasted_kwsyntax(f, args...; kwargs...) in Base.Broadcast at broadcast.jl:1297


julia> Base.broadcasted_kwsyntax(f, [1,2]; a=2)
Base.Broadcast.Broadcasted(#31, ([1, 2],))

So, yes, stick with the dot syntax :slight_smile: