add series_projections of contour plots

src/args.jl

@@ -287,6 +287,7 @@ const _series_defaults = KW(
     :hover              => nothing,  # text to display when hovering over the data points
     :stride             => (1,1),    # array stride for wireframe/surface, the first element is the row stride and the second is the column stride.
     :connections	  => nothing,  # tuple of arrays to specifiy connectivity of a 3d mesh
+    :series_projection  => :none, # allows e.g. projection to planes in a 3D plot 
     :extra_kwargs       => Dict()
 )
 

src/backends/pgfplotsx.jl

@@ -202,7 +202,7 @@ function (pgfx_plot::PGFPlotsXPlot)(plt::Plot{PGFPlotsXBackend})
             for series in series_list(sp)
                 if hascolorbar(series)
                     cg = get_colorgradient(series)
-                    cm = pgfx_colormap(get_colorgradient(series))
+                    cm = pgfx_colormap(cg)
                     PGFPlotsX.push_preamble!(
                         pgfx_plot.the_plot,
                         """\\pgfplotsset{
@@ -564,10 +564,34 @@ function pgfx_add_series!(::Val{:filledcontour}, axis, series_opt, series, serie
 end
 
 function pgfx_add_series!(::Val{:contour3d}, axis, series_opt, series, series_func, opt)
+    isproj = opt[:series_projection] != :none
+    if isproj
+        proj_letter, lim_value = getproperty(
+            (
+                xy = (:z, zlims(opt[:subplot])[1]),
+                yx = (:z, zlims(opt[:subplot])[2]),
+                yz = (:x, xlims(opt[:subplot])[1]),
+                zy = (:x, xlims(opt[:subplot])[2]),
+                xz = (:y, ylims(opt[:subplot])[1]),
+                zx = (:y, ylims(opt[:subplot])[2]),
+            ),
+            get(opt, :series_projection, :xz),
+        )
+        push!(series_opt,
+              "mesh" => nothing,
+              "mesh/check" => false,
+              "mesh/cols"  => size(opt[:z], 1),
+              "mesh/rows"  => size(opt[:z], 2),
+              "patch type" => "line",
+              "point meta" => "rawz",
+              "$proj_letter filter/.code" => "\\def\\pgfmathresult{$lim_value}"
+              )
+    else
         push!(
             series_opt,
             "contour prepared" => PGFPlotsX.Options("labels" => opt[:contour_labels]),
         )
+    end
     args = pgfx_series_arguments(series, opt)
     series_plot = series_func(series_opt, PGFPlotsX.Table(Contour.contours(args..., opt[:levels])))
     push!(axis, series_plot)

src/utils.jl

@@ -531,7 +531,7 @@ function get_colorgradient(series::Series)
     st = series[:seriestype]
     if st in (:surface, :heatmap) || isfilledcontour(series)
         series[:fillcolor]
-    elseif st in (:contour, :wireframe)
+    elseif st in (:contour, :wireframe, :contour3d)
         series[:linecolor]
     elseif series[:marker_z] !== nothing
         series[:markercolor]