[test][prefix][plotters] Add one new version of the scatter plotter

It will be useful for testing beat/beat.editor> v2

beat/core/test/prefix/plotters/user/scatter/2.json

+{
+  "dataformat": "plot/scatter/1",
+  "language": "python",
+  "parameters": {
+    "xlabel": {
+      "default": "X",
+      "type": "string",
+      "description": "The label of the X-axis (horizontal)"
+    },
+    "ylabel": {
+      "default": "Y",
+      "type": "string",
+      "description": "The label of the Y-axis (vertical)"
+    },
+    "title": {
+      "default": "Scatter plot",
+      "type": "string",
+      "description": "The title for this plot"
+    },
+    "xaxis_multiplier": {
+      "default": 1.0,
+      "type": "float64",
+      "description": "The multiplication factor for the X-axis (horizontal)"
+    },
+    "yaxis_multiplier": {
+      "default": 1.0,
+      "type": "float64",
+      "description": "The multiplication factor for the Y-axis (vertical)"
+    },
+    "line_attributes": {
+      "default": "",
+      "type": "string",
+      "description": "Scatter/Line attributes passed directly to Matplotlib"
+    },
+    "legend": {
+      "default": "",
+      "type": "string",
+      "description": "Short description of the data, to be added to the plot"
+    },
+    "grid": {
+      "default": false,
+      "type": "bool",
+      "description": "If we should draw grid lines or not for the plot"
+    },
+    "xaxis_log": {
+      "default": false,
+      "type": "bool",
+      "description": "If X-axis (horizontal) should be in log-scale"
+    },
+    "yaxis_log": {
+      "default": false,
+      "type": "bool",
+      "description": "If Y-axis (vertical) should be in log-scale"
+    },
+    "mimetype": {
+      "default": "image/png",
+      "description": "The type of image returned",
+      "type": "string",
+      "choice": [
+        "image/png",
+        "image/jpeg",
+        "application/pdf"
+      ]
+    }
+  }
+}

beat/core/test/prefix/plotters/user/scatter/2.py

+#!/usr/bin/env python
+# vim: set fileencoding=utf-8 :
+
+###################################################################################
+#                                                                                 #
+# Copyright (c) 2019 Idiap Research Institute, http://www.idiap.ch/               #
+# Contact: beat.support@idiap.ch                                                  #
+#                                                                                 #
+# Redistribution and use in source and binary forms, with or without              #
+# modification, are permitted provided that the following conditions are met:     #
+#                                                                                 #
+# 1. Redistributions of source code must retain the above copyright notice, this  #
+# list of conditions and the following disclaimer.                                #
+#                                                                                 #
+# 2. Redistributions in binary form must reproduce the above copyright notice,    #
+# this list of conditions and the following disclaimer in the documentation       #
+# and/or other materials provided with the distribution.                          #
+#                                                                                 #
+# 3. Neither the name of the copyright holder nor the names of its contributors   #
+# may be used to endorse or promote products derived from this software without   #
+# specific prior written permission.                                              #
+#                                                                                 #
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND #
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED   #
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE          #
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE    #
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL      #
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR      #
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER      #
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,   #
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE   #
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.            #
+#                                                                                 #
+###################################################################################
+
+
+import six
+import numpy
+import itertools
+
+# Make sure we won't require an X11 connection
+import matplotlib
+
+matplotlib.use("Agg")  # noqa need to happen before further imports
+
+from matplotlib.figure import Figure
+import matplotlib.pyplot as pyplot
+
+
+class Plotter:
+    def setup(self, parameters):
+
+        self.xlabel = parameters["xlabel"]
+        self.xaxis_multiplier = parameters["xaxis_multiplier"]
+        self.xaxis_log = parameters["xaxis_log"]
+        self.ylabel = parameters["ylabel"]
+        self.yaxis_multiplier = parameters["yaxis_multiplier"]
+        self.yaxis_log = parameters["yaxis_log"]
+        self.title = parameters["title"]
+        self.line_attributes = parameters["line_attributes"]
+        self.legend = parameters["legend"]
+        self.grid = parameters["grid"]
+        self.mimetype = parameters["mimetype"]
+
+        return True
+
+    def process(self, inputs):
+
+        # Creates the image to return
+        fig = Figure()
+        ax = fig.add_subplot(111)
+
+        if not isinstance(inputs, (list, tuple)):
+            inputs = [inputs]
+
+        self.legend = self.legend.split("&")
+        if isinstance(self.legend, str):
+            self.legend = [self.legend]
+
+        self.line_attributes = self.line_attributes.split("&")
+        if isinstance(self.line_attributes, str):
+            self.line_attributes = [self.line_attributes]
+
+        try:
+            Z = itertools.izip
+        except AttributeError:
+            Z = zip
+
+        C = itertools.cycle
+
+        for input, attributes, label in Z(
+            inputs, C(self.line_attributes), C(self.legend)
+        ):
+
+            # Massages the input data
+            final_data = numpy.array([(k.x, k.y) for k in input.data])
+            x = final_data[:, 0]
+            y = final_data[:, 1]
+            x *= self.xaxis_multiplier
+            y *= self.yaxis_multiplier
+
+            args = (x, y)
+            if attributes:
+                args = args + (attributes,)
+            kwargs = {}
+            if label:
+                kwargs["label"] = label
+
+            # Plots
+            ax.plot(*args, **kwargs)
+
+        # Sets plot attributes
+        ax.set_xlabel(self.xlabel)
+        ax.set_ylabel(self.ylabel)
+        ax.set_title(self.title)
+        ax.grid(self.grid)
+        if self.xaxis_log:
+            ax.set_xscale("log")
+        if self.yaxis_log:
+            ax.set_yscale("log")
+        if any(self.legend):
+            ax.legend()
+
+        # Returns the image
+        if six.PY2:
+            sio = six.StringIO()
+        else:
+            sio = six.BytesIO()
+
+        if self.mimetype == "image/png":
+            pyplot.savefig(sio, format="png")
+        elif self.mimetype == "image/jpeg":
+            pyplot.savefig(sio, format="jpeg")
+        elif self.mimetype == "application/pdf":
+            from matplotlib.backends.backend_pdf import FigureCanvasPdf
+
+            canvas = FigureCanvasPdf(fig)
+            canvas.print_figure(sio)
+
+        return sio.getvalue()

beat/core/test/test_plotter.py

@@ -44,20 +44,23 @@ from . import prefix
 
 
 def test_default():
-
     p = Plotter(prefix, data=None)
     nose.tools.assert_false(p.valid)
 
 
 def test_scatter():
+    for i in range(1, 3):
+        yield scatter, f"user/scatter/{i}"
+
 
-    p = Plotter(prefix, "user/scatter/1")
+def scatter(plotter_name):
+    p = Plotter(prefix, plotter_name)
     nose.tools.assert_true(p.valid, "\n  * %s" % "\n  * ".join(p.errors))
 
 
-def do_plot(mimetype):
+def do_plot(mimetype, plotter_name):
 
-    p = Plotter(prefix, "user/scatter/1")
+    p = Plotter(prefix, plotter_name)
     nose.tools.assert_true(p.valid)
 
     runnable = p.runner()
@@ -94,27 +97,34 @@ def do_plot(mimetype):
     return runnable.process(data)
 
 
-def test_plot_png():
-    fig = do_plot("image/png")
-    nose.tools.eq_(imghdr.what("test.png", fig), "png")
-    # with open('test.png', 'wb') as f: f.write(fig)
+def test_plot_image():
+    for i in range(1, 3):
+        for image_type in ["png", "jpeg"]:
+            yield plot_image, f"user/scatter/{i}", image_type
 
 
-def test_plot_jpeg():
-    fig = do_plot("image/jpeg")
-    nose.tools.eq_(imghdr.what("test.jpg", fig), "jpeg")
-    # with open('test.jpg', 'wb') as f: f.write(fig)
+def plot_image(plotter_name, image_type):
+    fig = do_plot(f"image/{image_type}", plotter_name)
+    nose.tools.eq_(imghdr.what(f"test.{image_type}", fig), image_type)
 
 
 def test_plot_pdf():
-    fig = do_plot("application/pdf")
+    for i in range(1, 3):
+        yield plot_pdf, f"user/scatter/{i}"
+
+
+def plot_pdf(plotter_name):
+    fig = do_plot("application/pdf", plotter_name)
     nose.tools.assert_true(fig.startswith(b"%PDF"))
-    # with open('test.pdf', 'wb') as f: f.write(fig)
 
 
 def test_plot_many_lines():
+    for i in range(1, 3):
+        yield plot_many_lines, f"user/scatter/{i}"
+
 
-    p = Plotter(prefix, "user/scatter/1")
+def plot_many_lines(plotter_name):
+    p = Plotter(prefix, plotter_name)
     nose.tools.assert_true(p.valid)
 
     data1 = p.dataformat.type(
@@ -166,4 +176,3 @@ def test_plot_many_lines():
 
     fig = runnable.process([data1, data2])
     nose.tools.eq_(imghdr.what("test.png", fig), "png")
-    # with open('test2.png', 'wb') as f: f.write(fig)