diff --git a/packages/squiggle-lang/__tests__/GenericDist/GenericDistSparkline_Test.res b/packages/squiggle-lang/__tests__/GenericDist/GenericDistSparkline_Test.res
index 8c29f7e4..8b3a8542 100644
--- a/packages/squiggle-lang/__tests__/GenericDist/GenericDistSparkline_Test.res
+++ b/packages/squiggle-lang/__tests__/GenericDist/GenericDistSparkline_Test.res
@@ -1,11 +1,6 @@
 open Jest
 open Expect
 
-let env: DistributionOperation.env = {
-  sampleCount: 100,
-  xyPointLength: 100,
-}
-
 let normalDist: GenericDist_Types.genericDist = Symbolic(#Normal({mean: 5.0, stdev: 2.0}))
 let uniformDist: GenericDist_Types.genericDist = Symbolic(#Uniform({low: 9.0, high: 10.0}))
 let betaDist: GenericDist_Types.genericDist = Symbolic(#Beta({alpha: 2.0, beta: 5.0}))
diff --git a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist.res b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist.res
index 7cacd634..d5fa99b6 100644
--- a/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist.res
+++ b/packages/squiggle-lang/src/rescript/Distributions/PointSetDist/PointSetDist.res
@@ -168,20 +168,13 @@ let pdf = (f: float, t: t) => {
 let inv = T.Integral.yToX
 let cdf = T.Integral.xToY
 
-let diff = (arr: array<float>): array<float> =>
-  Belt.Array.zipBy(arr, Belt.Array.sliceToEnd(arr, 1), (left, right) => right -. left)
-
-let rec rangeByFloat = (start : float, end: float, step: float) => 
-  start > end ?
-    []
-    : Belt.Array.concat([start], rangeByFloat(start +. step, end, step))
 
 @genType
 let toSparkline = (buckets: int, t: t ): string => {
   let size : float = T.maxX(t) -. T.minX(t)
   let stepSize = size /. Belt.Int.toFloat(buckets)
-  let cdf = rangeByFloat(T.minX(t), T.maxX(t), stepSize) -> Belt.Array.map(val => cdf(val,t))
-  Sparklines.create(diff(cdf), ())
+  let cdfImage = E.A.rangeByFloat(~step=stepSize, T.minX(t), T.maxX(t)) -> Belt.Array.map(val => cdf(val,t))
+  Sparklines.create(E.A.diff(cdfImage), ())
 }
 
 let doN = (n, fn) => {
diff --git a/packages/squiggle-lang/src/rescript/Utility/E.res b/packages/squiggle-lang/src/rescript/Utility/E.res
index e36b6124..b3119da3 100644
--- a/packages/squiggle-lang/src/rescript/Utility/E.res
+++ b/packages/squiggle-lang/src/rescript/Utility/E.res
@@ -292,6 +292,14 @@ module A = {
   let rangeFloat = (~step=1, start, stop) =>
     Belt.Array.rangeBy(start, stop, ~step) |> fmap(Belt.Int.toFloat)
 
+  let diff = (arr: array<float>): array<float> =>
+    Belt.Array.zipBy(arr, Belt.Array.sliceToEnd(arr, 1), (left, right) => right -. left)
+
+  let rec rangeByFloat = (~step: float=1.0, start : float, end: float) : array<float> => 
+    start > end ?
+      []
+      : Belt.Array.concat([start], rangeByFloat(~step, start +. step, end))
+
   // This zips while taking the longest elements of each array.
   let zipMaxLength = (array1, array2) => {
     let maxLength = Int.max(length(array1), length(array2))