# Vector type-recipe plotting in Julia

**URL:** <https://discourse.julialang.org/t/vector-type-recipe-plotting-in-julia/92986>\
**Category:** General Usage\
**Tags:** plotting, plots, recipe\
**Created:** [January 15, 2023, 8:27am UTC](https://discourse.julialang.org/t/vector-type-recipe-plotting-in-julia/92986 "2023-01-15T08:27:17Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![singularitti](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/singularitti/32/17678_2.png) [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Post date:** [January 15, 2023, 8:27am UTC](https://discourse.julialang.org/t/vector-type-recipe-plotting-in-julia/92986/1 "2023-01-15T08:27:17Z")

</div>

I saw this question on [stackoverflow](https://stackoverflow.com/questions/66571646/vector-type-recipe-plotting-in-julia). And I also have the same question: Could we define `plot` for one data point and it automatically works for an `Array` of it?

IIs there a way to write a plotting type recipe for a type `T` and then have Julia somehow infer a corresponding recipe for the type `Vector{T}`?

Simple example, suppose I have a box struct `B`, and I write a simple type-recipe for plotting it:

```julia
using Plots

struct B
    x0
    x1
    y0
    y1
end
bshape(b::B) = Shape([b.x0,b.x1,b.x1,b.x0],[b.y0,b.y0,b.y1,b.y1])
@recipe f(::Type{B}, b::B) = bshape(b)

```

So now `plot(B(0,1,2,3))` plots a filled rectangle like I wanted. Now say I have an array of `B`s, and I want to plot all the rectangles in a single plot by calling `plot(bs)`. Simply defining the type recipe for `B` doesn’t accomplish this. I can write another type recipe for vectors of `B` like this:

```julia
@recipe f(::Type{Vector{B}}, bs::Vector{B}) = bshape.(bs)

```

But, first of all, I don’t really love this, it’s got some repeated code. I’d rather be able to tell Julia to just use the original type recipe. Also, e.g., if I want to let each box be able to determine other things about how it gets plotted, say:

```julia
@recipe function f(::Type{B}, b::B)
    fillcolor --> (b.x0==0 ? :red : :blue)
    bshape(b)
end

```

At this point the vector version, as written above, won’t do what I want. I can probably modify it somehow, but it seems like there should be a “correct” way to do this.

---

<div class="post-metadata">

**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [January 15, 2023, 7:22pm UTC](https://discourse.julialang.org/t/vector-type-recipe-plotting-in-julia/92986/2 "2023-01-15T19:22:22Z")

</div>

I suspect that it might be simpler to write a method for each case, scalar and vector, as recipes are not functions we can broadcast.

For the last recipe, in the vector case one could write something like:

```julia
@recipe function f(::Type{Vector{B}}, b::Vector{B})
    fillcolor --> permutedims([(a.x0==0 ? :red : :blue) for a in b])
    bshape.(b)
end

```