diff --git a/__tests__/CDF__Test.re b/__tests__/CDF__Test.re
index 66c35fdf..33ad8700 100644
--- a/__tests__/CDF__Test.re
+++ b/__tests__/CDF__Test.re
@@ -100,4 +100,47 @@ describe("CDF", () => {
       expect(Dist.findX(4.)) |> toEqual(1.)
     });
   });
+
+  describe("convertWithAlternativeXs", () => {
+    open Functions;
+    let xs = up(1, 9);
+    let ys = up(20, 28);
+    module Dist =
+      CDF.Make({
+        let shape = CDF.order({xs, ys});
+      });
+
+    let xs2 = up(3, 7);
+    module Dist2 =
+      CDF.Make({
+        let shape = Dist.convertWithAlternativeXs(xs2);
+      });
+
+    test("#1", () => {
+      expect(Dist2.xs) |> toEqual([|3., 4., 5., 6., 7.|])
+    });
+    test("#2", () => {
+      expect(Dist2.ys) |> toEqual([|22., 23., 24., 25., 26.|])
+    });
+  });
+
+  describe("convertToNewLength", () => {
+    open Functions;
+    let xs = up(1, 9);
+    let ys = up(50, 58);
+    module Dist =
+      CDF.Make({
+        let shape = CDF.order({xs, ys});
+      });
+    module Dist2 =
+      CDF.Make({
+        let shape = Dist.convertToNewLength(3);
+      });
+    test("#1", () => {
+      expect(Dist2.xs) |> toEqual([|1., 5., 9.|])
+    });
+    test("#2", () => {
+      expect(Dist2.ys) |> toEqual([|50., 54., 58.|])
+    });
+  });
 });
diff --git a/__tests__/Functions__Test.re b/__tests__/Functions__Test.re
index d32f44e8..5dda5e3d 100644
--- a/__tests__/Functions__Test.re
+++ b/__tests__/Functions__Test.re
@@ -76,15 +76,17 @@ describe("Functions", () => {
     expect(Functions.random(1, 5)) |> toBeGreaterThanOrEqual(1)
   });
   test("up#1", () => {
-    expect(Functions.up(1, 5)) |> toEqual([|1, 2, 3, 4, 5|])
+    expect(Functions.up(1, 5)) |> toEqual([|1., 2., 3., 4., 5.|])
   });
   test("up#2", () => {
-    expect(Functions.up(-1, 5)) |> toEqual([|(-1), 0, 1, 2, 3, 4, 5|])
+    expect(Functions.up(-1, 5))
+    |> toEqual([|(-1.), 0., 1., 2., 3., 4., 5.|])
   });
   test("down#1", () => {
-    expect(Functions.down(5, 1)) |> toEqual([|5, 4, 3, 2, 1|])
+    expect(Functions.down(5, 1)) |> toEqual([|5., 4., 3., 2., 1.|])
   });
   test("down#2", () => {
-    expect(Functions.down(5, -1)) |> toEqual([|5, 4, 3, 2, 1, 0, (-1)|])
+    expect(Functions.down(5, -1))
+    |> toEqual([|5., 4., 3., 2., 1., 0., (-1.)|])
   });
 });
diff --git a/src/utility/lib/CDF.re b/src/utility/lib/CDF.re
index 09095ae2..b5f9221e 100644
--- a/src/utility/lib/CDF.re
+++ b/src/utility/lib/CDF.re
@@ -78,5 +78,17 @@ module Make = (Config: Config) => {
       };
     };
   };
+  let convertWithAlternativeXs = (newXs: array(float)): DistTypes.xyShape => {
+    let newYs = Belt.Array.map(newXs, findY);
+    {xs: newXs, ys: newYs};
+  };
+  let convertToNewLength = (newLength: int): DistTypes.xyShape => {
+    Functions.(
+      range(min(xs), max(xs), newLength) |> convertWithAlternativeXs
+    );
+  };
+  let sampleSingle = (): float => Js.Math.random() |> findY;
+  let sample = (size: int): array(float) =>
+    Belt.Array.makeBy(size, i => sampleSingle());
   1;
 };
diff --git a/src/utility/lib/Functions.re b/src/utility/lib/Functions.re
index 26a8bf20..998084cc 100644
--- a/src/utility/lib/Functions.re
+++ b/src/utility/lib/Functions.re
@@ -13,9 +13,14 @@ let sum = Belt.Array.reduce(_, 0., (i, j) => i +. j);
 let mean = a => sum(a) /. (Array.length(a) |> float_of_int);
 let min = a => Belt.Array.reduce(a, a[0], (i, j) => i < j ? i : j);
 let max = a => Belt.Array.reduce(a, a[0], (i, j) => i > j ? i : j);
-let up = (a, b) => Array.make(b - a + 1, a) |> Array.mapi((i, c) => c + i);
+let up = (a, b) =>
+  Array.make(b - a + 1, a)
+  |> Array.mapi((i, c) => c + i)
+  |> Belt.Array.map(_, float_of_int);
 let down = (a, b) =>
-  Array.make(a - b + 1, a) |> Array.mapi((i, c) => c - i);
+  Array.make(a - b + 1, a)
+  |> Array.mapi((i, c) => c - i)
+  |> Belt.Array.map(_, float_of_int);
 let range = (min: float, max: float, n: int): array(float) => {
   switch (n) {
   | 0 => [||]
diff --git a/src/utility/lib/continuousDistribution.js b/src/utility/lib/continuousDistribution.js
index 1e639398..bd777908 100644
--- a/src/utility/lib/continuousDistribution.js
+++ b/src/utility/lib/continuousDistribution.js
@@ -136,6 +136,7 @@ class ContinuousDistribution {
   }
 
   /**
+   * @Done
    * @param {number[]} xs
    * @return {ContinuousDistribution}
    */
@@ -145,6 +146,7 @@ class ContinuousDistribution {
   }
 
   /**
+   * Done
    * @param {number} newLength
    * @return {ContinuousDistribution}
    */
@@ -154,6 +156,7 @@ class ContinuousDistribution {
   }
 
   /**
+   * @Done
    * @return {number}
    */
   sampleSingle() {
@@ -162,6 +165,7 @@ class ContinuousDistribution {
   }
 
   /**
+   * @Done
    * Poduce n samples, using ``sampleSingle`` for each.
    * @param size
    * @return {number[]}