Fix points in LineDots plots not being found when clicked on

sohstationviewer/view/plotting/plotting_widget/plotting_widget.py

@@ -447,6 +447,9 @@ class PlottingWidget(QtWidgets.QScrollArea):
             return
 
         clicked_data = chan_data['data'][0][real_idxes[0]]
+        # The data stored by the data object is not converted, so we need to
+        # do the conversion before displaying it to the user.
+        clicked_data *= chan_data['chan_db_info']['convertFactor']
         if chan_id.startswith('Disk Usage'):
             clicked_data = get_disk_size_format(clicked_data)
         if hasattr(ax, 'unit_bw'):

sohstationviewer/view/plotting/plotting_widget/plotting_widget_helper.py

 from typing import Dict, Optional
+
+import numpy
 import numpy as np
 
 
@@ -11,6 +13,8 @@ def get_index_from_data_picked(
     :param val: data value of a clicked point
     :return real_indexes: list index of data point inside np.ndarray found
     """
+    np.set_printoptions(suppress=True)
+
     if chan_data['chan_db_info']['plotType'] == 'upDownDots':
         # actual plotting has value -0.5 or 0.5;
         # the value need to be convert to 0 or 1
@@ -21,11 +25,29 @@ def get_index_from_data_picked(
                 "multiColorDotsEqualOnLowerBound", "dotForTime"]):
         # don't check val because the plot's data don't affect the position
         # of the data point and overlap isn't an issue.
-        real_indexes = np.where(chan_data['times'][0] == tm)[0]
+        closest_point_idx = np.where(chan_data['times'][0] == tm)[0]
     else:
-        real_indexes = np.where((chan_data['times'][0] == tm) &
-                                (chan_data['data'][0] == val))[0]
-    return real_indexes
+        # The data is converted during plotting, so the data provided by
+        # matplotlib is different from the raw data. In order to fix this
+        # problem, we need to convert matplotlib's data back to raw data.
+        val = val / chan_data['chan_db_info']['convertFactor']
+        # Converting the data back and forth can introduce floating point
+        # errors, so we have to use numpy.isclose() instead of the standard
+        # standard comparison.
+        real_indexes = np.where(
+            (chan_data['times'][0] == tm) &
+            (numpy.isclose(chan_data['data'][0], val))
+        )[0]
+        if len(real_indexes) == 0:
+            closest_point_idx = real_indexes
+        else:
+            closest_point_idx = real_indexes[
+                np.argmin(np.abs(chan_data['data'][0][real_indexes] - val))
+            ]
+            # We turn the index into a numpy array with one element in order to
+            # conform to the signature of this function.
+            closest_point_idx = np.array([closest_point_idx])
+    return closest_point_idx
 
 
 def get_total_miny_maxy(

tests/view/plotting/plotting_widget/test_plotting_widget_helper.py

@@ -12,17 +12,20 @@ class TestGetIndexFromDataPicked(BaseTestCase):
             'CH1': {
                 'times': [np.array([1, 2, 3, 4, 5, 6, 6])],
                 'data': [np.array([1, 1, 0, 1, 1, 0, 0])],
-                'chan_db_info': {'plotType': 'upDownDots'}
+                'chan_db_info': {'plotType': 'upDownDots',
+                                 'convertFactor': 1}
             },
             'CH2': {
                 'times': [np.array([1, 2, 3, 3, 5, 6])],
                 'data': [np.array([6, 9, 7, 4, 3, 9])],
-                'chan_db_info': {'plotType': 'linesDots'}
+                'chan_db_info': {'plotType': 'linesDots',
+                                 'convertFactor': 1}
             },
             'CH3': {
                 'times': [np.array([1, 2, 3, 4, 5, 6])],
                 'data': [np.array([6, 9, 7, 4, 3, 9])],
-                'chan_db_info': {'plotType': 'dotForTime'}
+                'chan_db_info': {'plotType': 'dotForTime',
+                                 'convertFactor': 1}
             }
         }
 
@@ -71,7 +74,40 @@ class TestGetIndexFromDataPicked(BaseTestCase):
     def test_2_overlapped_points(self):
         real_idxes = get_index_from_data_picked(
             self.plotting_data['CH1'], 6, -0.5)
-        self.assertEqual(real_idxes.tolist(), [5, 6])
+        self.assertEqual(real_idxes.tolist(), [5])
+
+    def test_convert_factor_not_1(self):
+        # upDownDots channels always have a convert factor of 1 in practice, so
+        # we don't need to test them.
+        # multiColorDots and dotForTime channels only cares about the time,
+        # which is not affected by the convert factor. Thus, we don't need to
+        # test them.
+        plotting_data = {
+            'CH1': {
+                'times': [np.array([1, 2, 3, 4, 5, 6])],
+                'data': [np.array([6, 9, 7, 4, 3, 9])],
+                'chan_db_info': {'plotType': 'linesDots',
+                                 'convertFactor': 0.1}
+            },
+        }
+        with self.subTest('Data point can be found'):
+            expected = [1]
+            actual = list(
+                get_index_from_data_picked(plotting_data['CH1'], 2, 0.9)
+            )
+            self.assertEqual(expected, actual)
+        with self.subTest('Time not in range'):
+            expected = []
+            actual = list(
+                get_index_from_data_picked(plotting_data['CH1'], 20, 0.9)
+            )
+            self.assertEqual(expected, actual)
+        with self.subTest('Data not found'):
+            expected = []
+            actual = list(
+                get_index_from_data_picked(plotting_data['CH1'], 2, 9)
+            )
+            self.assertEqual(expected, actual)
 
 
 class TestGetTotalMinyMaxy(BaseTestCase):