Rectbin errors out when given max and min values

[grero]

For some of my plots, I like to add a rectangular shaded region to highlight e.g. a sub-region used for a statistical comparison between two distributions. In Winston, I can accomplish this using the FillBetween type. I noticed that Gadfly has the ribbon geometry, but that seems to be bound to a line, i.e. it will only draw a ribbon around an existing line. It would be really useful to have a dedicated ShadedRegion (or a more fitting name) geometry for this use.

[tbreloff]

You could just draw a polygon instead. Or make the line invisible (0 width
or transparent)

On Monday, May 16, 2016, Roger Herikstad notifications@github.com wrote:

For some of my plots, I like to add a rectangular shaded region to
highlight e.g. a sub-region used for a statistical comparison between two
distributions. In Winston, I can accomplish this using the FillBetween
type. I noticed that Gadfly has the ribbon geometry, but that seems to be
bound to a line, i.e. it will only draw a ribbon around an existing line.
It would be really useful to have a dedicated ShadedRegion (or a more
fitting name) geometry for this use.

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#845

[Mattriks]

According to the guide (http://dcjones.github.io/Gadfly.jl/geom_rectbin.html), Geom.rectbin is supposed to be able to do this for arbitrary rectangles, but I get an error when using the xmin=, ymin=, xmax=, ymax= option. So my solution (yet again!) is to make your own geometry:

using Colors, Compose, DataFrames

immutable RectangleGeometry <: Gadfly.GeometryElement 
     tag::Symbol 

    function RectangleGeometry(; tag::Symbol=Gadfly.Geom.empty_tag) 
         new(tag) 
     end 
end 


function Gadfly.element_aesthetics(::RectangleGeometry) 
    [:xmin, :ymin, :xmax, :ymax, :color] 
end 


function Gadfly.render(geom::RectangleGeometry, theme::Gadfly.Theme, aes::Gadfly.Aesthetics) 

     default_aes = Gadfly.Aesthetics() 
    default_aes.color = DataArrays.PooledDataArray(RGBA{Float32}[theme.default_color]) 
    aes = Gadfly.inherit(aes, default_aes)
    alpha_color = map(theme.lowlight_color, aes.color)

    ctx = context()
    compose!(ctx, rectangle(aes.xmin, aes.ymin, 
      aes.xmax-aes.xmin, aes.ymax-aes.ymin, geom.tag), fill(alpha_color)) 
    return compose!(context(order=4), svgclass("geometry"), ctx)
end

rect1 = RectangleGeometry

# in the next line, opacity = 0.2
theme1 = Theme(lowlight_color=c -> RGBA(c.r, c.g, c.b, 0.2))

D = DataFrame( x1=[-2,0], y1=[-1,0], x2=[1,4], y2=[1,2], col=["a","b"] )
p = plot(
    layer(x=1:5, y=randn(5), Geom.point, Theme(default_color=colorant"red")),
    layer(D, xmin=:x1, ymin=:y1, xmax=:x2, ymax=:y2,  color=:col, rect1, theme1)
)

Looking similar to my code in #844 and #842 !

[grero]

That works beautifully, thanks!

[bjarthur]

fixed by #993