Allow only drawing every N'th dot in a path

This makes the output file much smaller and thus much easier for latex
to compile. In a lot of cases, apparently, all the dots are not needed
to produce smooth plots.

Author: Gorshanov Vadim

src/tikzplotlib/_path.py

@@ -303,7 +303,7 @@ def draw_pathcollection(data, obj):
 
         plot_table = []
         plot_table.append("  ".join(labels) + "\n")
-        for row in dd_strings:
+        for row in dd_strings[::data["every n dot"]]:
             plot_table.append(" ".join(row) + "\n")
 
         if data["externalize tables"]:

src/tikzplotlib/_save.py

@@ -40,6 +40,7 @@ def get_tikz_code(
     float_format: str = ".15g",
     table_row_sep: str = "\n",
     flavor: str = "latex",
+    every_n_dot: int = 1,
 ):
     """Main function. Here, the recursion into the image starts and the
     contents are picked up. The actual file gets written in this routine.
@@ -136,6 +137,9 @@ def get_tikz_code(
                    Default is ``"latex"``.
     :type flavor: str
 
+    :param every_n_dot: if path is encountered, only draw every Nth dot
+    :type every_n_dot: int
+
     :returns: None
 
     The following optional attributes of matplotlib's objects are recognized
@@ -176,6 +180,7 @@ def get_tikz_code(
     data["legend colors"] = []
     data["add axis environment"] = add_axis_environment
     data["show_info"] = show_info
+    data["every n dot"] = every_n_dot
     # rectangle_legends is used to keep track of which rectangles have already
     # had \addlegendimage added. There should be only one \addlegenimage per
     # bar chart data series.