Added docstrings and cleanup

packages/squiggle-lang/__tests__/E/splitContinuousAndDiscrete_test.res

@@ -2,7 +2,7 @@ open Jest
 open TestHelpers
 
 let prepareInputs = (ar, minWeight) =>
-  E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(ar, minWeight) |> (
+  E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(ar, ~minDiscreteWeight=minWeight) |> (
     ((c, disc)) => (c, disc |> E.FloatFloatMap.toArray)
   )
 
@@ -33,14 +33,14 @@ describe("Continuous and discrete splits", () => {
 
   let (_, discrete1) = E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(
     makeDuplicatedArray(10),
-    2,
+    ~minDiscreteWeight=2,
   )
   let toArr1 = discrete1 |> E.FloatFloatMap.toArray
   makeTest("splitMedium at count=10", toArr1 |> Belt.Array.length, 10)
 
   let (_c, discrete2) = E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(
     makeDuplicatedArray(500),
-    2,
+    ~minDiscreteWeight=2,
   )
   let toArr2 = discrete2 |> E.FloatFloatMap.toArray
   makeTest("splitMedium at count=500", toArr2 |> Belt.Array.length, 500)

packages/squiggle-lang/src/rescript/Distributions/SampleSetDist/SampleSetDist_ToPointSet.res

@@ -63,8 +63,11 @@ let toPointSetDist = (
   (),
 ): Internals.Types.outputs => {
   Array.fast_sort(compare, samples)
-  let minDiscreteToKeep = max(2, E.A.length(samples) / 10);
+  let minDiscreteToKeep = MagicNumbers.ToPointSet.minDiscreteToKeep(samples)
-  let (continuousPart, discretePart) = E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(samples, minDiscreteToKeep)
+  let (continuousPart, discretePart) = E.A.Sorted.Floats.splitContinuousAndDiscreteForMinWeight(
+    samples,
+    ~minDiscreteWeight=minDiscreteToKeep,
+  )
   let length = samples |> E.A.length |> float_of_int
   let discrete: PointSetTypes.discreteShape =
     discretePart

packages/squiggle-lang/src/rescript/MagicNumbers.res

@@ -22,3 +22,16 @@ module OpCost = {
   let wildcardCost = 1000
   let monteCarloCost = Environment.defaultSampleCount
 }
+
+module ToPointSet = {
+  /*
+  This function chooses the minimum amount of duplicate samples that need
+  to exist in order for this to be considered discrete. The tricky thing 
+  is that there are some operations that create duplicate continuous samples, 
+  so we can't guarantee that these only will occur because the fundamental 
+  structure is meant to be discrete. I chose this heuristic because I think 
+  it would strike a reasonable trade-off, but I’m really unsure what’s 
+  best right now.
+ */
+  let minDiscreteToKeep = samples => max(20, E.A.length(samples) / 50)
+}

packages/squiggle-lang/src/rescript/Utility/E.res

@@ -522,7 +522,12 @@ module A = {
       let makeIncrementalDown = (a, b) =>
         Array.make(a - b + 1, a) |> Array.mapi((i, c) => c - i) |> Belt.Array.map(_, float_of_int)
 
-      let splitContinuousAndDiscreteForDuplicates = (sortedArray: array<float>) => {
+      /*
+      This function goes through a sorted array and divides it into two different clusters:
+      continuous samples and discrete samples. The discrete samples are stored in a mutable map.
+      Samples are thought to be discrete if they have any duplicates.
+ */
+      let _splitContinuousAndDiscreteForDuplicates = (sortedArray: array<float>) => {
         let continuous: array<float> = []
         let discrete = FloatFloatMap.empty()
         Belt.Array.forEachWithIndex(sortedArray, (index, element) => {
@@ -545,11 +550,18 @@ module A = {
         (continuous, discrete)
       }
 
+      /*
+      This function works very similarly to splitContinuousAndDiscreteForDuplicates. The one major difference
+      is that you can specify a minDiscreteWeight.  If the min discreet weight is 4, that would mean that
+      at least four elements needed from a specific value for that to be kept as discrete. This is important
+      because in some cases, we can expect that some common elements will be generated by regular operations.
+      The final continous array will be sorted.
+ */
       let splitContinuousAndDiscreteForMinWeight = (
         sortedArray: array<float>,
-        minDiscreteWeight: int,
+        ~minDiscreteWeight: int,
       ) => {
-        let (continuous, discrete) = splitContinuousAndDiscreteForDuplicates(sortedArray)
+        let (continuous, discrete) = _splitContinuousAndDiscreteForDuplicates(sortedArray)
         let keepFn = v => Belt.Float.toInt(v) >= minDiscreteWeight
         let (discreteToKeep, discreteToIntegrate) = FloatFloatMap.partition(
           ((_, v)) => keepFn(v),
@@ -559,7 +571,6 @@ module A = {
           discreteToIntegrate->FloatFloatMap.toArray
           |> fmap(((k, v)) => Belt.Array.makeBy(Belt.Float.toInt(v), _ => k))
           |> Belt.Array.concatMany
-
         let newContinuous = concat(continuous, newContinousSamples)
         newContinuous |> Array.fast_sort(floatCompare)
         (newContinuous, discreteToKeep)