Add set_slice method to StateAttributeLimitsHelper

glue/core/state_objects.py

@@ -8,6 +8,7 @@
 from echo import (delay_callback, CallbackProperty,
                                 HasCallbackProperties, CallbackList)
 from glue.core.state import saver, loader
+from glue.core.subset import SliceSubsetState
 from glue.core.component_id import PixelComponentID
 from glue.core.exceptions import IncompatibleAttribute
 
@@ -288,15 +289,15 @@ class StateAttributeLimitsHelper(StateAttributeCacheHelper):
     """
 
     values_names = ('lower', 'upper')
-    modifiers_names = ('log', 'percentile')
+    modifiers_names = ('log', 'percentile', 'subset_state')
 
     def __init__(self, state, attribute, random_subset=10000, margin=0, **kwargs):
 
         super(StateAttributeLimitsHelper, self).__init__(state, attribute, **kwargs)
 
         self.margin = margin
         self.random_subset = random_subset
-        self.subset_indices = None
+        self.subset_state = None
 
         if self.attribute is not None:
 
@@ -341,16 +342,20 @@ def update_values(self, force=False, use_default_modifiers=False, **properties):
             if percentile == 100:
                 lower = self.data.compute_statistic('minimum', cid=self.component_id,
                                                     finite=True, positive=log,
+                                                    subset_state = self.subset_state,
                                                     random_subset=self.random_subset)
                 upper = self.data.compute_statistic('maximum', cid=self.component_id,
                                                     finite=True, positive=log,
+                                                    subset_state = self.subset_state,
                                                     random_subset=self.random_subset)
             else:
                 lower = self.data.compute_statistic('percentile', cid=self.component_id,
                                                     percentile=exclude, positive=log,
+                                                    subset_state = self.subset_state,
                                                     random_subset=self.random_subset)
                 upper = self.data.compute_statistic('percentile', cid=self.component_id,
                                                     percentile=100 - exclude, positive=log,
+                                                    subset_state = self.subset_state,
                                                     random_subset=self.random_subset)
 
             if not isinstance(lower, np.datetime64) and np.isnan(lower):
@@ -375,6 +380,9 @@ def update_values(self, force=False, use_default_modifiers=False, **properties):
     def flip_limits(self):
         self.set(lower=self.upper, upper=self.lower)
 
+    def set_slice(self, slices):
+        self.set(subset_state=None if slices is None else SliceSubsetState(self.data, slices))
+
 
 class StateAttributeSingleValueHelper(StateAttributeCacheHelper):
 

glue/core/tests/test_state_objects.py

@@ -4,6 +4,7 @@
 
 from echo import CallbackProperty, ListCallbackProperty
 from glue.core import Data, DataCollection
+from glue.core.subset import SliceSubsetState
 
 from .test_state import clone
 from ..state_objects import (State, StateAttributeLimitsHelper,
@@ -182,6 +183,35 @@ def test_manual_edit(self):
         assert self.helper.upper == 234
         assert self.helper.log
 
+    def test_subset(self):
+
+        # Set subset to compute limits from
+        self.helper.subset_state = SliceSubsetState(self.helper.data, [slice(6000)])
+        self.helper.percentile = 100
+        # self.helper.update_values()
+        assert_allclose(self.helper.lower, -100)
+        assert_allclose(self.helper.upper, 19.992)
+        self.helper.percentile = 90
+        assert_allclose(self.helper.lower, -94.0004)
+        assert_allclose(self.helper.upper, 13.9924)
+
+    def test_slice(self):
+
+        # Set subset to compute limits from slice
+        self.helper.set_slice([slice(2000, 8000)])
+        self.helper.percentile = 100
+        # self.helper.update_values()
+        assert_allclose(self.helper.lower, -59.996)
+        assert_allclose(self.helper.upper, 59.996)
+        self.helper.percentile = 90
+        assert_allclose(self.helper.lower, -53.9964)
+        assert_allclose(self.helper.upper, 53.9964)
+
+        self.helper.set_slice(None)
+        self.helper.percentile = 95
+        assert_allclose(self.helper.lower, -95)
+        assert_allclose(self.helper.upper, 95)
+
 
 class TestStateAttributeSingleValueHelper():
 

glue/viewers/image/state.py

@@ -572,6 +572,19 @@ def flip_limits(self):
         """
         self.attribute_lim_helper.flip_limits()
 
+    def set_slice(self, slices):
+        """
+        Select a subset slice for determining image levels.
+
+        Parameters
+        ----------
+        slices : iterable of :class:`slice` or `None`
+            An iterable containing :class:`slice` objects that can instantiate
+            a :class:`SliceSubsetState` and has to be consistent with the
+            shape of `self.data`; `None` to unslice.
+        """
+        self.attribute_lim_helper.set_slice(slices)
+
     def reset_contrast_bias(self):
         with delay_callback(self, 'contrast', 'bias'):
             self.contrast = 1