FIgure out stddev

enso-org · Apr 7, 2022 · 8cc25b9 · 8cc25b9
1 parent c303784
commit 8cc25b9
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Showing 3 changed files with 22 additions and 17 deletions.
diff --git a/distribution/lib/Standard/Test/0.0.0-dev/src/Main.enso b/distribution/lib/Standard/Test/0.0.0-dev/src/Main.enso
@@ -272,12 +272,16 @@ Error.should_equal _ frames_to_skip=0 = here.fail_match_on_unexpected_error this
          example_should_equal =
             1.00000001 . should_equal 1.00000002 epsilon=0.0001
 Decimal.should_equal : Decimal -> Decimal -> Integer -> Assertion
-Decimal.should_equal that (epsilon = 0) (frames_to_skip=0) = case this.equals that epsilon of
-    True -> Success
-    False ->
-        loc = Meta.get_source_location 2+frames_to_skip
-        msg = this.to_text + " did not equal " + that.to_text + " (at " + loc + ")."
-        Panic.throw (Failure msg)
+Decimal.should_equal that (epsilon = 0) (frames_to_skip=0) =
+    matches = case that of
+        Number -> this.equals that epsilon
+        _ -> False
+    case matches of
+        True -> Success
+        False ->
+            loc = Meta.get_source_location 2+frames_to_skip
+            msg = this.to_text + " did not equal " + that.to_text + " (at " + loc + ")."
+            Panic.throw (Failure msg)
 
 ## Asserts that the given `Boolean` is `True`
 

diff --git a/std-bits/table/src/main/java/org/enso/table/aggregations/StandardDeviation.java b/std-bits/table/src/main/java/org/enso/table/aggregations/StandardDeviation.java
@@ -1,11 +1,10 @@
 package org.enso.table.aggregations;
 
+import java.util.List;
 import org.enso.table.data.column.storage.Storage;
 import org.enso.table.data.table.Column;
 import org.enso.table.data.table.problems.InvalidAggregation;
 
-import java.util.List;
-
 /***
  * Aggregate Column computing the standard deviation of a group.
  */
@@ -25,7 +24,7 @@ public Calculation(double value) {
   private final Storage storage;
   private final boolean population;
 
-  public StandardDeviation(String name, Column column,boolean population) {
+  public StandardDeviation(String name, Column column, boolean population) {
     super(name, Storage.Type.DOUBLE);
     this.storage = column.getStorage();
     this.population = population;
@@ -34,12 +33,13 @@ public StandardDeviation(String name, Column column,boolean population) {
   @Override
   public Object aggregate(List<Integer> indexes) {
     Calculation current = null;
-    for (int row: indexes) {
+    for (int row : indexes) {
       Object value = storage.getItemBoxed(row);
       if (value != null) {
         Double dValue = CastToDouble(value);
         if (dValue == null) {
-          this.addProblem(new InvalidAggregation(this.getName(), row, "Cannot convert to a number."));
+          this.addProblem(
+              new InvalidAggregation(this.getName(), row, "Cannot convert to a number."));
           return null;
         }
 
@@ -48,12 +48,14 @@ public Object aggregate(List<Integer> indexes) {
         } else {
           current.count++;
           current.total += dValue;
-          current.total_sqr += dValue*dValue;
+          current.total_sqr += dValue * dValue;
         }
       }
     }
-    return current == null ? null :
-        (population ? 1 : Math.sqrt(current.count / (current.count - 1.0))) *
-            Math.sqrt(current.total_sqr / current.count - Math.pow(current.total / current.count, 2));
+
+    if (current == null) return null;
+    if (!population && current.count <= 1) return null;
+    return (population ? 1 : Math.sqrt(current.count / (current.count - 1.0)))
+        * Math.sqrt(current.total_sqr / current.count - Math.pow(current.total / current.count, 2));
   }
 }
diff --git a/test/Table_Tests/src/Aggregate_Spec.enso b/test/Table_Tests/src/Aggregate_Spec.enso
@@ -892,7 +892,7 @@ aggregate_spec prefix table empty_table table_builder materialize is_database te
             m1 = materialize r1
             m1.columns.length . should_equal 2
             m1.columns.first.at 0 . should_equal Nothing
-            m1.columns.first.at 0 . should_equal Nothing
+            m1.columns.second.at 0 . should_equal 0
 
     Test.group prefix+"Table.aggregate should correctly select result types" pending=pending <|
         Test.specify " widening to decimals on Average" <|
@@ -930,7 +930,6 @@ aggregate_spec prefix table empty_table table_builder materialize is_database te
             table = table_builder [["X", [1, 2, 3, 4, Nothing]]]
             r1 = table.aggregate [Standard_Deviation "X" (population=True), Standard_Deviation "X" (population=False)]
             r1.row_count.should_equal 1
-            r1.print
             m1 = materialize r1
             m1.columns.length . should_equal 2
             m1.columns.first.at 0 . should_equal 1.1180339887499 epsilon=0.000001