Error bands example, minor API additions

.github/workflows/ci.yml

@@ -18,15 +18,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        branch: [version-1-4, devel]
+        branch: [version-1-6, version-2-0, devel]
         target: [linux, macos, windows]
         include:
           - target: linux
-            builder: ubuntu-18.04
+            builder: ubuntu-latest
           - target: macos
-            builder: macos-10.15
+            builder: macos-latest
           - target: windows
-            builder: windows-2019
+            builder: windows-latest
     name: '${{ matrix.target }} (${{ matrix.branch }})'
     runs-on: ${{ matrix.builder }}
     steps:

changelog.org

@@ -1,3 +1,10 @@
+* v0.3.3
+- add ~hideLine~ for ~Trace~ object for scatter plots, in order to set
+  the line width to 0. Used for backwards compatibility, because
+  setting a value of 0 would be the default.
+- add ~FillMode~ value of ~toSelf~ to allow colored bands / filled
+  polygons
+- add example for a manual error band    
 * v0.3.2
 - fix behavior of =show= when =--threads:on= for =Grid= usage, in
   particular for example 18. =filename= argument is now optional,

examples/all.nim

@@ -14,3 +14,4 @@ import fig15_horizontalBarPlot
 import fig16_plotly_sugar
 import fig17_color_font_legend
 import fig18_subplots
+import fig21_error_band

examples/fig21_error_band.nim

@@ -0,0 +1,43 @@
+import sequtils
+import plotly
+import chroma
+from std / algorithm import reversed
+
+# simple example showcasing error bands (by hand)
+
+let
+  d = Trace[float](mode: PlotMode.LinesMarkers, `type`: PlotType.Scatter)
+  size = @[16.float]
+d.marker = Marker[float](size: size)
+d.xs = @[1'f64, 2, 3, 4, 5]
+d.ys = @[1'f64, 2, 1, 9, 5]
+
+# Create a Trace for the error band
+let
+  dBand = Trace[float](mode: PlotMode.Lines, `type`: PlotType.Scatter,
+                       opacity: 0.75, # opacity 75% to be prettier
+                       fill: ToSelf, # `ToSelf` means the filling is done to its own data
+                       hideLine: true) # line width 0 disables the outline
+# Create X data that is first increasing and then decreasing
+dBand.xs = concat(d.xs, d.xs.reversed)
+# Assign the actual ribbon band. Currently needs to be a seq
+dBand.marker = Marker[float](color: @[color(0.6, 0.6, 0.6)])
+
+# define some errors we will use (symmetric)
+let yErr = d.ys.mapIt(0.25)
+# now create the first upper band range
+var yErrs = newSeqOfCap[float](d.ys.len * 2) # first upper, then lower
+for i in 0 ..< d.ys.len: # upper errors
+  yErrs.add(d.ys[i] + yErr[i])
+# and now the lower
+for i in countdown(d.ys.high, 0): # lower errors
+  yErrs.add(d.ys[i] - yErr[i])
+dBand.ys = yErrs
+
+let
+  layout = Layout(title: "testing", width: 1200, height: 400,
+                  xaxis: Axis(title: "my x-axis"),
+                  yaxis: Axis(title: "y-axis too"), autosize: false)
+  p = Plot[float](layout: layout, traces: @[d, dBand]) # assign both traces
+echo p.save()
+p.show()

src/plotly/api.nim

@@ -342,8 +342,10 @@ func `%`*(t: Trace): JsonNode =
     if t.xs.len > 0:
       fields.parseBarFields(t)
   of PlotType.Scatter, PlotType.ScatterGL:
-    if t.lineWidth > 0:
+    if not t.hideLine and t.lineWidth > 0:
       fields["line"] = %* {"width": t.lineWidth}
+    elif t.hideLine:
+      fields["line"] = %* {"width": 0}
   else:
     discard
 

src/plotly/plotly_types.nim

@@ -43,6 +43,7 @@ type
     Unset = ""
     ToNextY = "tonexty"
     ToZeroY = "tozeroy"
+    ToSelf = "toself"
 
   PlotMode* {.pure.} = enum
     Lines = "lines"
@@ -219,6 +220,7 @@ type
       orientation*: Orientation
     of Scatter, ScatterGL:
       lineWidth*: int
+      hideLine*: bool # can be used to force line to be width 0 (for backwards compatiblity)
     else:
       discard
 

tests/plotly/test_api.nim

@@ -495,20 +495,21 @@ suite "show w/ filename without threads fails compilation":
                        xs: xs, ys: ys)
   let plt = Plot[float](layout: layout, traces: @[d])
 
-  ## NOTE: the following tests assume the test is compiled without `--threads:on`!
-  test "Plot - saveImage fails":
-    check compileFails(plt.saveImage("test.svg"))
+  when not compileOption("threads"):
+    ## NOTE: the following tests assume the test is compiled without `--threads:on`!
+    test "Plot - saveImage fails":
+      check compileFails(plt.saveImage("test.svg"))
 
-  test "PlotJson - saveImage fails":
-    check compileFails(plt.toPlotJson.saveImage("test.svg"))
+    test "PlotJson - saveImage fails":
+      check compileFails(plt.toPlotJson.saveImage("test.svg"))
 
-  test "Plot - show w/ filename w/o threads:on fails":
-    check compileFails(plt.show("test.svg"))
+    test "Plot - show w/ filename w/o threads:on fails":
+      check compileFails(plt.show("test.svg"))
 
-  test "PlotJson - show w/ filename w/o threads:on fails":
-    check compileFails(plt.toPlotJson.show("test.svg"))
+    test "PlotJson - show w/ filename w/o threads:on fails":
+      check compileFails(plt.toPlotJson.show("test.svg"))
 
-  test "Grid - show w/ filename w/o threads:on fails":
-    var grid = createGrid(1)
-    grid[0] = plt
-    check compileFails(grid.show("test.svg"))
+    test "Grid - show w/ filename w/o threads:on fails":
+      var grid = createGrid(1)
+      grid[0] = plt
+      check compileFails(grid.show("test.svg"))