Add multi plot grid support

Author: ruivieira

docs/README.md

@@ -146,3 +146,22 @@ figure6.dpi = 180
 ```
 
 ![plot](custom_size.png)
+
+### side-by-side plots
+
+```nim
+let figure8 = newFigure()
+figure8.grid = (rows: 1, cols: 2)
+figure8.size = (8.0, 4.0)
+figure8.add newLinePlot[int,float](x, y)
+figure8.subplot
+figure8.add lp6
+figure8.add hl6
+for i in 0..6:
+    let vl6 = newVerticalLine(PI * float(i) * 50.0)
+    vl6.linestyle = "-."
+    vl6.colour = "blue"
+    figure8.add vl6
+```
+
+![plot](side_by_side.png)

docs/examples.nim

@@ -89,4 +89,19 @@ figure7.save("docs/annotation.png")
 # dpi
 figure6.size = (20.0, 2.0)
 figure6.dpi = 180
-figure6.save("docs/custom_size.png")
+figure6.save("docs/custom_size.png")
+
+# multiple plots
+let figure8 = newFigure()
+figure8.grid = (rows: 1, cols: 2)
+figure8.size = (8.0, 4.0)
+figure8.add newLinePlot[int,float](x, y)
+figure8.subplot
+figure8.add lp6
+figure8.add hl6
+for i in 0..6:
+    let vl6 = newVerticalLine(PI * float(i) * 50.0)
+    vl6.linestyle = "-."
+    vl6.colour = "blue"
+    figure8.add vl6
+figure8.save("docs/side_by_side.png")

docs/side_by_side.png

@@ -18,10 +18,12 @@ type
     python*: string
     script*: seq[string]
     latex*: bool
-    plots*: seq[Plot]
+    plots*: seq[seq[Plot]]
     font*: tuple[family: string, style: string]
     dpi*: int
     size*: tuple[w: float, h: float]
+    grid*: tuple[rows: int, cols: int]
+    index: int
 
 proc save*(figure: Figure, dest: string) =
   var script = newSeq[string]()
@@ -39,8 +41,15 @@ proc save*(figure: Figure, dest: string) =
     script.add &"fig = plt.figure(figsize=({figure.size.w},{figure.size.h}))"
   else:
     script.add "fig = plt.figure()"
-  for p in figure.plots:
-    script.add p.render
+  for i in 0..<len(figure.plots):
+    echo &"i = {i}"
+    echo &"plt.subplot({figure.grid.rows}, {figure.grid.cols}, {i+1})"
+    script.add &"plt.subplot({figure.grid.rows}, {figure.grid.cols}, {i+1})"
+    let plots = figure.plots[i]
+    echo &"#plots = {len(plots)}"
+    for j in 0..<len(plots):
+      echo &"j = {j}"
+      script.add plots[j].render
   if figure.dpi > 0:
     script.add fmt"plt.savefig('{dest}', format='png', transparent=False, dpi={figure.dpi})"
   else:
@@ -51,20 +60,28 @@ proc save*(figure: Figure, dest: string) =
   writeFile(name, script_str)
   echo name
   discard execShellCmd fmt"/usr/local/bin/python3 {name}"
-
-
 
 proc newFigure*(): Figure =
   Figure(python: "/usr/local/bin/python3", 
          script: newSeq[string](), 
          latex: false,
          font: ("", ""),
          dpi: 0,
-         size: (0.0, 0.0))
+         size: (0.0, 0.0),
+         grid: (1, 1),
+         index: 0,
+         plots: @[])
 
 proc add*(figure: Figure, plot: Plot) =
-  figure.plots.add plot
-
+  if len(figure.plots)==0:
+    figure.plots.add @[]
+  echo &"Add plot to {figure.index}"
+  figure.plots[figure.index].add plot
+
+proc subplot*(figure: Figure) =
+  figure.plots.add @[]
+  figure.index += 1
+  
 # Line plots
 type LinePlot[A, B] = ref object of Plot
   linestyle*: string