Set up new expressionTree directory

__tests__/Distributions__Test.re

@@ -383,9 +383,9 @@ describe("Shape", () => {
     let numSamples = 10000;
     open Distributions.Shape;
     let normal: SymbolicTypes.symbolicDist = `Normal({mean, stdev});
-    let normalShape = TreeNode.toShape(numSamples, `Leaf(`SymbolicDist(normal)));
+    let normalShape = ExpressionTree.toShape(numSamples, `Leaf(`SymbolicDist(normal)));
     let lognormal = SymbolicDist.Lognormal.fromMeanAndStdev(mean, stdev);
-    let lognormalShape = TreeNode.toShape(numSamples, `Leaf(`SymbolicDist(lognormal)));
+    let lognormalShape = ExpressionTree.toShape(numSamples, `Leaf(`SymbolicDist(lognormal)));
 
     makeTestCloseEquality(
       "Mean of a normal",

src/components/DistBuilder3.re

@@ -37,13 +37,13 @@ module DemoDist = {
     let parsed1 = MathJsParser.fromString(guesstimatorString);
     let shape =
       switch (parsed1) {
-      | Ok(r) => Some(TreeNode.toShape(10000, r))
+      | Ok(r) => Some(ExpressionTree.toShape(10000, r))
       | _ => None
       };
 
     let str =
       switch (parsed1) {
-      | Ok(r) => TreeNode.toString(r)
+      | Ok(r) => ExpressionTree.toString(r)
       | Error(e) => e
       };
 

src/components/Drawer.re

@@ -389,7 +389,7 @@ module Draw = {
     let numSamples = 3000;
 
     let normal: SymbolicTypes.symbolicDist = `Normal({mean, stdev});
-    let normalShape = TreeNode.toShape(numSamples, `Leaf(`SymbolicDist(normal)));
+    let normalShape = ExpressionTree.toShape(numSamples, `Leaf(`SymbolicDist(normal)));
     let xyShape: Types.xyShape =
       switch (normalShape) {
       | Mixed(_) => {xs: [||], ys: [||]}

src/distPlus/distribution/AlgebraicCombinations.re

@@ -110,7 +110,7 @@ let toDiscretePointMassesFromTriangulars =
 };
 
 let combineShapesContinuousContinuous =
-    (op: SymbolicTypes.algebraicOperation, s1: DistTypes.xyShape, s2: DistTypes.xyShape)
+    (op: ExpressionTypes.algebraicOperation, s1: DistTypes.xyShape, s2: DistTypes.xyShape)
     : DistTypes.xyShape => {
   let t1n = s1 |> XYShape.T.length;
   let t2n = s2 |> XYShape.T.length;

src/distPlus/distribution/Distributions.re

@@ -282,7 +282,7 @@ module Continuous = {
   let combineAlgebraicallyWithDiscrete =
       (
         ~downsample=false,
-        op: SymbolicTypes.algebraicOperation,
+        op: ExpressionTypes.algebraicOperation,
         t1: t,
         t2: DistTypes.discreteShape,
       ) => {
@@ -291,7 +291,7 @@ module Continuous = {
     let t1n = t1s |> XYShape.T.length;
     let t2n = t2s |> XYShape.T.length;
 
-    let fn = SymbolicTypes.Algebraic.toFn(op);
+    let fn = Operation.Algebraic.toFn(op);
 
     let outXYShapes: array(array((float, float))) =
       Belt.Array.makeUninitializedUnsafe(t2n);
@@ -333,7 +333,7 @@ module Continuous = {
   };
 
   let combineAlgebraically =
-      (~downsample=false, op: SymbolicTypes.algebraicOperation, t1: t, t2: t) => {
+      (~downsample=false, op: ExpressionTypes.algebraicOperation, t1: t, t2: t) => {
     let s1 = t1 |> getShape;
     let s2 = t2 |> getShape;
     let t1n = s1 |> XYShape.T.length;
@@ -413,7 +413,7 @@ module Discrete = {
   /* This multiples all of the data points together and creates a new discrete distribution from the results.
      Data points at the same xs get added together. It may be a good idea to downsample t1 and t2 before and/or the result after. */
   let combineAlgebraically =
-      (op: SymbolicTypes.algebraicOperation, t1: t, t2: t) => {
+      (op: ExpressionTypes.algebraicOperation, t1: t, t2: t) => {
     let t1s = t1 |> getShape;
     let t2s = t2 |> getShape;
     let t1n = t1s |> XYShape.T.length;
@@ -426,7 +426,7 @@ module Discrete = {
         t2.knownIntegralSum,
       );
 
-    let fn = SymbolicTypes.Algebraic.toFn(op);
+    let fn = Operation.Algebraic.toFn(op);
     let xToYMap = E.FloatFloatMap.empty();
 
     for (i in 0 to t1n - 1) {
@@ -840,7 +840,7 @@ module Mixed = {
     });
 
   let combineAlgebraically =
-      (~downsample=false, op: SymbolicTypes.algebraicOperation, t1: t, t2: t)
+      (~downsample=false, op: ExpressionTypes.algebraicOperation, t1: t, t2: t)
       : t => {
     // Discrete convolution can cause a huge increase in the number of samples,
     // so we'll first downsample.
@@ -914,7 +914,7 @@ module Shape = {
     ));
 
   let combineAlgebraically =
-      (op: SymbolicTypes.algebraicOperation, t1: t, t2: t): t => {
+      (op: ExpressionTypes.algebraicOperation, t1: t, t2: t): t => {
     switch (t1, t2) {
     | (Continuous(m1), Continuous(m2)) =>
       DistTypes.Continuous(
@@ -1096,7 +1096,7 @@ module Shape = {
         };
     });
 
-  let operate = (distToFloatOp: SymbolicTypes.distToFloatOperation, s) =>
+  let operate = (distToFloatOp: ExpressionTypes.distToFloatOperation, s) =>
     switch (distToFloatOp) {
     | `Pdf(f) => pdf(f, s)
     | `Inv(f) => inv(f, s)

src/distPlus/expressionTree/ExpressionTree.re

@@ -0,0 +1,22 @@
+open ExpressionTypes.ExpressionTree;
+
+let toShape = (sampleCount: int, node: node) => {
+  let renderResult =
+    ExpressionTreeEvaluator.toLeaf(`Operation(`Render(node)), sampleCount);
+
+  switch (renderResult) {
+  | Ok(`Leaf(`RenderedDist(rs))) =>
+    let continuous = Distributions.Shape.T.toContinuous(rs);
+    let discrete = Distributions.Shape.T.toDiscrete(rs);
+    let shape = MixedShapeBuilder.buildSimple(~continuous, ~discrete);
+    shape |> E.O.toExt("Could not build final shape.");
+  | Ok(_) => E.O.toExn("Rendering failed.", None)
+  | Error(message) => E.O.toExn("No shape found, error: " ++ message, None)
+  };
+};
+
+let rec toString =
+  fun
+  | `Leaf(`SymbolicDist(d)) => SymbolicDist.T.toString(d)
+  | `Leaf(`RenderedDist(_)) => "[shape]"
+  | `Operation(op) => Operation.T.toString(toString, op);

src/distPlus/expressionTree/ExpressionTreeEvaluator.re

@@ -0,0 +1,294 @@
+/* This module represents a tree node. */
+open ExpressionTypes;
+open ExpressionTypes.ExpressionTree;
+
+type t = node;
+type tResult = node => result(node, string);
+
+/* Given two random variables A and B, this returns the distribution
+   of a new variable that is the result of the operation on A and B.
+   For instance, normal(0, 1) + normal(1, 1) -> normal(1, 2).
+   In general, this is implemented via convolution. */
+module AlgebraicCombination = {
+  let toTreeNode = (op, t1, t2) =>
+    `Operation(`AlgebraicCombination((op, t1, t2)));
+  let tryAnalyticalSolution =
+    fun
+    | `Operation(
+        `AlgebraicCombination(
+          operation,
+          `Leaf(`SymbolicDist(d1)),
+          `Leaf(`SymbolicDist(d2)),
+        ),
+      ) as t =>
+      switch (SymbolicDist.T.attemptAnalyticalOperation(d1, d2, operation)) {
+      | `AnalyticalSolution(symbolicDist) =>
+        Ok(`Leaf(`SymbolicDist(symbolicDist)))
+      | `Error(er) => Error(er)
+      | `NoSolution => Ok(t)
+      }
+    | t => Ok(t);
+
+  // todo: I don't like the name evaluateNumerically that much, if this renders and does it algebraically. It's tricky.
+  let evaluateNumerically = (algebraicOp, operationToLeaf, t1, t2) => {
+    // force rendering into shapes
+    let renderShape = r => operationToLeaf(`Render(r));
+    switch (renderShape(t1), renderShape(t2)) {
+    | (Ok(`Leaf(`RenderedDist(s1))), Ok(`Leaf(`RenderedDist(s2)))) =>
+      Ok(
+        `Leaf(
+          `RenderedDist(
+            Distributions.Shape.combineAlgebraically(algebraicOp, s1, s2),
+          ),
+        ),
+      )
+    | (Error(e1), _) => Error(e1)
+    | (_, Error(e2)) => Error(e2)
+    | _ => Error("Could not render shapes.")
+    };
+  };
+
+  let toLeaf =
+      (
+        operationToLeaf,
+        algebraicOp: ExpressionTypes.algebraicOperation,
+        t1: t,
+        t2: t,
+      )
+      : result(node, string) =>
+    toTreeNode(algebraicOp, t1, t2)
+    |> tryAnalyticalSolution
+    |> E.R.bind(
+         _,
+         fun
+         | `Leaf(d) => Ok(`Leaf(d)) // the analytical simplifaction worked, nice!
+         | `Operation(_) =>
+           // if not, run the convolution
+           evaluateNumerically(algebraicOp, operationToLeaf, t1, t2),
+       );
+};
+
+module VerticalScaling = {
+  let toLeaf = (operationToLeaf, scaleOp, t, scaleBy) => {
+    // scaleBy has to be a single float, otherwise we'll return an error.
+    let fn = Operation.Scale.toFn(scaleOp);
+    let knownIntegralSumFn = Operation.Scale.toKnownIntegralSumFn(scaleOp);
+    let renderedShape = operationToLeaf(`Render(t));
+
+    switch (renderedShape, scaleBy) {
+    | (Ok(`Leaf(`RenderedDist(rs))), `Leaf(`SymbolicDist(`Float(sm)))) =>
+      Ok(
+        `Leaf(
+          `RenderedDist(
+            Distributions.Shape.T.mapY(
+              ~knownIntegralSumFn=knownIntegralSumFn(sm),
+              fn(sm),
+              rs,
+            ),
+          ),
+        ),
+      )
+    | (Error(e1), _) => Error(e1)
+    | (_, _) => Error("Can only scale by float values.")
+    };
+  };
+};
+
+module PointwiseCombination = {
+  let pointwiseAdd = (operationToLeaf, t1, t2) => {
+    let renderedShape1 = operationToLeaf(`Render(t1));
+    let renderedShape2 = operationToLeaf(`Render(t2));
+
+    switch (renderedShape1, renderedShape2) {
+    | (Ok(`Leaf(`RenderedDist(rs1))), Ok(`Leaf(`RenderedDist(rs2)))) =>
+      Ok(
+        `Leaf(
+          `RenderedDist(
+            Distributions.Shape.combinePointwise(
+              ~knownIntegralSumsFn=(a, b) => Some(a +. b),
+              (+.),
+              rs1,
+              rs2,
+            ),
+          ),
+        ),
+      )
+    | (Error(e1), _) => Error(e1)
+    | (_, Error(e2)) => Error(e2)
+    | _ => Error("Could not perform pointwise addition.")
+    };
+  };
+
+  let pointwiseMultiply = (operationToLeaf, t1, t2) => {
+    // TODO: construct a function that we can easily sample from, to construct
+    // a RenderedDist. Use the xMin and xMax of the rendered shapes to tell the sampling function where to look.
+    Error(
+      "Pointwise multiplication not yet supported.",
+    );
+  };
+
+  let toLeaf = (operationToLeaf, pointwiseOp, t1, t2) => {
+    switch (pointwiseOp) {
+    | `Add => pointwiseAdd(operationToLeaf, t1, t2)
+    | `Multiply => pointwiseMultiply(operationToLeaf, t1, t2)
+    };
+  };
+};
+
+module Truncate = {
+  module Simplify = {
+    let tryTruncatingNothing: tResult =
+      fun
+      | `Operation(`Truncate(None, None, `Leaf(d))) => Ok(`Leaf(d))
+      | t => Ok(t);
+
+    let tryTruncatingUniform: tResult =
+      fun
+      | `Operation(`Truncate(lc, rc, `Leaf(`SymbolicDist(`Uniform(u))))) => {
+          // just create a new Uniform distribution
+          let newLow = max(E.O.default(neg_infinity, lc), u.low);
+          let newHigh = min(E.O.default(infinity, rc), u.high);
+          Ok(`Leaf(`SymbolicDist(`Uniform({low: newLow, high: newHigh}))));
+        }
+      | t => Ok(t);
+
+    let attempt = (leftCutoff, rightCutoff, t): result(node, string) => {
+      let originalTreeNode =
+        `Operation(`Truncate((leftCutoff, rightCutoff, t)));
+
+      originalTreeNode
+      |> tryTruncatingNothing
+      |> E.R.bind(_, tryTruncatingUniform);
+    };
+  };
+
+  let evaluateNumerically = (leftCutoff, rightCutoff, operationToLeaf, t) => {
+    // TODO: use named args in renderToShape; if we're lucky we can at least get the tail
+    // of a distribution we otherwise wouldn't get at all
+    let renderedShape = operationToLeaf(`Render(t));
+
+    switch (renderedShape) {
+    | Ok(`Leaf(`RenderedDist(rs))) =>
+      let truncatedShape =
+        rs |> Distributions.Shape.T.truncate(leftCutoff, rightCutoff);
+      Ok(`Leaf(`RenderedDist(rs)));
+    | Error(e1) => Error(e1)
+    | _ => Error("Could not truncate distribution.")
+    };
+  };
+
+  let toLeaf =
+      (
+        operationToLeaf,
+        leftCutoff: option(float),
+        rightCutoff: option(float),
+        t: node,
+      )
+      : result(node, string) => {
+    t
+    |> Simplify.attempt(leftCutoff, rightCutoff)
+    |> E.R.bind(
+         _,
+         fun
+         | `Leaf(d) => Ok(`Leaf(d)) // the analytical simplifaction worked, nice!
+         | `Operation(_) =>
+           evaluateNumerically(leftCutoff, rightCutoff, operationToLeaf, t),
+       ); // if not, run the convolution
+  };
+};
+
+module Normalize = {
+  let rec toLeaf = (operationToLeaf, t: node): result(node, string) => {
+    switch (t) {
+    | `Leaf(`RenderedDist(s)) =>
+      Ok(`Leaf(`RenderedDist(Distributions.Shape.T.normalize(s))))
+    | `Leaf(`SymbolicDist(_)) => Ok(t)
+    | `Operation(op) =>
+      operationToLeaf(op) |> E.R.bind(_, toLeaf(operationToLeaf))
+    };
+  };
+};
+
+module FloatFromDist = {
+  let symbolicToLeaf = (distToFloatOp: distToFloatOperation, s) => {
+    SymbolicDist.T.operate(distToFloatOp, s)
+    |> E.R.bind(_, v => Ok(`Leaf(`SymbolicDist(`Float(v)))));
+  };
+  let renderedToLeaf =
+      (distToFloatOp: distToFloatOperation, rs: DistTypes.shape)
+      : result(node, string) => {
+    Distributions.Shape.operate(distToFloatOp, rs)
+    |> (v => Ok(`Leaf(`SymbolicDist(`Float(v)))));
+  };
+  let rec toLeaf =
+          (operationToLeaf, distToFloatOp: distToFloatOperation, t: node)
+          : result(node, string) => {
+    switch (t) {
+    | `Leaf(`SymbolicDist(s)) => symbolicToLeaf(distToFloatOp, s) // we want to evaluate the distToFloatOp on the symbolic dist
+    | `Leaf(`RenderedDist(rs)) => renderedToLeaf(distToFloatOp, rs)
+    | `Operation(op) =>
+      E.R.bind(operationToLeaf(op), toLeaf(operationToLeaf, distToFloatOp))
+    };
+  };
+};
+
+module Render = {
+  let rec toLeaf =
+          (
+            operationToLeaf: operation => result(t, string),
+            sampleCount: int,
+            t: node,
+          )
+          : result(t, string) => {
+    switch (t) {
+    | `Leaf(`SymbolicDist(d)) =>
+      Ok(`Leaf(`RenderedDist(SymbolicDist.T.toShape(sampleCount, d))))
+    | `Leaf(`RenderedDist(_)) as t => Ok(t) // already a rendered shape, we're done here
+    | `Operation(op) =>
+      E.R.bind(operationToLeaf(op), toLeaf(operationToLeaf, sampleCount))
+    };
+  };
+};
+
+let rec operationToLeaf =
+        (sampleCount: int, op: operation): result(t, string) => {
+  // the functions that convert the Operation nodes to Leaf nodes need to
+  // have a way to call this function on their children, if their children are themselves Operation nodes.
+  switch (op) {
+  | `AlgebraicCombination(algebraicOp, t1, t2) =>
+    AlgebraicCombination.toLeaf(
+      operationToLeaf(sampleCount),
+      algebraicOp,
+      t1,
+      t2 // we want to give it the option to render or simply leave it as is
+    )
+  | `PointwiseCombination(pointwiseOp, t1, t2) =>
+    PointwiseCombination.toLeaf(
+      operationToLeaf(sampleCount),
+      pointwiseOp,
+      t1,
+      t2,
+    )
+  | `VerticalScaling(scaleOp, t, scaleBy) =>
+    VerticalScaling.toLeaf(operationToLeaf(sampleCount), scaleOp, t, scaleBy)
+  | `Truncate(leftCutoff, rightCutoff, t) =>
+    Truncate.toLeaf(operationToLeaf(sampleCount), leftCutoff, rightCutoff, t)
+  | `FloatFromDist(distToFloatOp, t) =>
+    FloatFromDist.toLeaf(operationToLeaf(sampleCount), distToFloatOp, t)
+  | `Normalize(t) => Normalize.toLeaf(operationToLeaf(sampleCount), t)
+  | `Render(t) => Render.toLeaf(operationToLeaf(sampleCount), sampleCount, t)
+  };
+};
+
+/* This function recursively goes through the nodes of the parse tree,
+   replacing each Operation node and its subtree with a Data node.
+   Whenever possible, the replacement produces a new Symbolic Data node,
+   but most often it will produce a RenderedDist.
+   This function is used mainly to turn a parse tree into a single RenderedDist
+   that can then be displayed to the user. */
+let toLeaf = (node: t, sampleCount: int): result(t, string) => {
+  switch (node) {
+  | `Leaf(d) => Ok(`Leaf(d))
+  | `Operation(op) => operationToLeaf(sampleCount, op)
+  };
+};

src/distPlus/expressionTree/ExpressionTypes.re

@@ -0,0 +1,24 @@
+type algebraicOperation = [ | `Add | `Multiply | `Subtract | `Divide];
+type pointwiseOperation = [ | `Add | `Multiply];
+type scaleOperation = [ | `Multiply | `Exponentiate | `Log];
+type distToFloatOperation = [ | `Pdf(float) | `Inv(float) | `Mean | `Sample];
+
+type abstractOperation('a) = [
+  | `AlgebraicCombination(algebraicOperation, 'a, 'a)
+  | `PointwiseCombination(pointwiseOperation, 'a, 'a)
+  | `VerticalScaling(scaleOperation, 'a, 'a)
+  | `Render('a)
+  | `Truncate(option(float), option(float), 'a)
+  | `Normalize('a)
+  | `FloatFromDist(distToFloatOperation, 'a)
+];
+
+module ExpressionTree = {
+  type leaf = [
+    | `SymbolicDist(SymbolicTypes.symbolicDist)
+    | `RenderedDist(DistTypes.shape)
+  ];
+
+  type node = [ | `Leaf(leaf) | `Operation(operation)]
+  and operation = abstractOperation(node);
+};

src/distPlus/expressionTree/MathJsParser.re

@@ -86,13 +86,13 @@ module MathAdtToDistDst = {
         );
   };
 
-  let normal: array(arg) => result(TreeNode.treeNode, string) =
+  let normal: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(mean), Value(stdev)|] =>
       Ok(`Leaf(`SymbolicDist(`Normal({mean, stdev}))))
     | _ => Error("Wrong number of variables in normal distribution");
 
-  let lognormal: array(arg) => result(TreeNode.treeNode, string) =
+  let lognormal: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(mu), Value(sigma)|] =>
       Ok(`Leaf(`SymbolicDist(`Lognormal({mu, sigma}))))
@@ -114,7 +114,7 @@ module MathAdtToDistDst = {
       }
     | _ => Error("Wrong number of variables in lognormal distribution");
 
-  let to_: array(arg) => result(TreeNode.treeNode, string) =
+  let to_: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(low), Value(high)|] when low <= 0.0 && low < high => {
         Ok(
@@ -134,31 +134,31 @@ module MathAdtToDistDst = {
       Error("Low value must be less than high value.")
     | _ => Error("Wrong number of variables in lognormal distribution");
 
-  let uniform: array(arg) => result(TreeNode.treeNode, string) =
+  let uniform: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(low), Value(high)|] =>
       Ok(`Leaf(`SymbolicDist(`Uniform({low, high}))))
     | _ => Error("Wrong number of variables in lognormal distribution");
 
-  let beta: array(arg) => result(TreeNode.treeNode, string) =
+  let beta: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(alpha), Value(beta)|] =>
       Ok(`Leaf(`SymbolicDist(`Beta({alpha, beta}))))
     | _ => Error("Wrong number of variables in lognormal distribution");
 
-  let exponential: array(arg) => result(TreeNode.treeNode, string) =
+  let exponential: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(rate)|] =>
       Ok(`Leaf(`SymbolicDist(`Exponential({rate: rate}))))
     | _ => Error("Wrong number of variables in Exponential distribution");
 
-  let cauchy: array(arg) => result(TreeNode.treeNode, string) =
+  let cauchy: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(local), Value(scale)|] =>
       Ok(`Leaf(`SymbolicDist(`Cauchy({local, scale}))))
     | _ => Error("Wrong number of variables in cauchy distribution");
 
-  let triangular: array(arg) => result(TreeNode.treeNode, string) =
+  let triangular: array(arg) => result(ExpressionTypes.ExpressionTree.node, string) =
     fun
     | [|Value(low), Value(medium), Value(high)|] =>
       Ok(`Leaf(`SymbolicDist(`Triangular({low, medium, high}))))
@@ -166,7 +166,7 @@ module MathAdtToDistDst = {
 
   let multiModal =
       (
-        args: array(result(TreeNode.treeNode, string)),
+        args: array(result(ExpressionTypes.ExpressionTree.node, string)),
         weights: option(array(float)),
       ) => {
     let weights = weights |> E.O.default([||]);
@@ -215,7 +215,7 @@ module MathAdtToDistDst = {
     };
   };
 
-  let arrayParser = (args: array(arg)): result(TreeNode.treeNode, string) => {
+  let arrayParser = (args: array(arg)): result(ExpressionTypes.ExpressionTree.node, string) => {
     let samples =
       args
       |> E.A.fmap(
@@ -241,7 +241,7 @@ module MathAdtToDistDst = {
   };
 
   let operationParser =
-      (name: string, args: array(result(TreeNode.treeNode, string))) => {
+      (name: string, args: array(result(ExpressionTypes.ExpressionTree.node, string))) => {
     let toOkAlgebraic = r => Ok(`Operation(`AlgebraicCombination(r)));
     let toOkTrunctate = r => Ok(`Operation(`Truncate(r)));
     switch (name, args) {
@@ -347,7 +347,7 @@ module MathAdtToDistDst = {
     | Symbol(_) => Error("Symbol not valid as top level")
     | Object(_) => Error("Object not valid as top level");
 
-  let run = (r): result(TreeNode.treeNode, string) =>
+  let run = (r): result(ExpressionTypes.ExpressionTree.node, string) =>
     r |> MathAdtCleaner.run |> topLevel;
 };
 

src/distPlus/expressionTree/Operation.re

@@ -0,0 +1,93 @@
+open ExpressionTypes;
+
+module Algebraic = {
+  type t = algebraicOperation;
+  let toFn: (t, float, float) => float =
+    fun
+    | `Add => (+.)
+    | `Subtract => (-.)
+    | `Multiply => ( *. )
+    | `Divide => (/.);
+
+  let applyFn = (t, f1, f2) => {
+    switch (t, f1, f2) {
+    | (`Divide, _, 0.) => Error("Cannot divide $v1 by zero.")
+    | _ => Ok(toFn(t, f1, f2))
+    };
+  };
+
+  let toString =
+    fun
+    | `Add => "+"
+    | `Subtract => "-"
+    | `Multiply => "*"
+    | `Divide => "/";
+
+  let format = (a, b, c) => b ++ " " ++ toString(a) ++ " " ++ c;
+};
+
+module Pointwise = {
+  type t = pointwiseOperation;
+  let toString =
+    fun
+    | `Add => "+"
+    | `Multiply => "*";
+
+  let format = (a, b, c) => b ++ " " ++ toString(a) ++ " " ++ c;
+};
+
+module DistToFloat = {
+  type t = distToFloatOperation;
+
+  let format = (operation, value) =>
+    switch (operation) {
+    | `Pdf(f) => {j|pdf(x=$f,$value)|j}
+    | `Inv(f) => {j|inv(x=$f,$value)|j}
+    | `Sample => "sample($value)"
+    | `Mean => "mean($value)"
+    };
+};
+
+module Scale = {
+  type t = scaleOperation;
+  let toFn =
+    fun
+    | `Multiply => ( *. )
+    | `Exponentiate => ( ** )
+    | `Log => ((a, b) => log(a) /. log(b));
+
+  let format = (operation: t, value, scaleBy) =>
+    switch (operation) {
+    | `Multiply => {j|scaleMultiply($value, $scaleBy) |j}
+    | `Exponentiate => {j|ScaleExponentiate($value, $scaleBy) |j}
+    | `Log => {j|ScaleLog($value, $scaleBy) |j}
+    };
+
+  let toKnownIntegralSumFn =
+    fun
+    | `Multiply => ((a, b) => Some(a *. b))
+    | `Exponentiate => ((_, _) => None)
+    | `Log => ((_, _) => None);
+};
+
+module T = {
+  let truncateToString =
+      (left: option(float), right: option(float), nodeToString) => {
+    let left = left |> E.O.dimap(Js.Float.toString, () => "-inf");
+    let right = right |> E.O.dimap(Js.Float.toString, () => "inf");
+    {j|truncate($nodeToString, $left, $right)|j};
+  };
+  let toString = nodeToString =>
+    fun
+    | `AlgebraicCombination(op, t1, t2) =>
+      Algebraic.format(op, nodeToString(t1), nodeToString(t2))
+    | `PointwiseCombination(op, t1, t2) =>
+      Pointwise.format(op, nodeToString(t1), nodeToString(t2))
+    | `VerticalScaling(scaleOp, t, scaleBy) =>
+      Scale.format(scaleOp, nodeToString(t), nodeToString(scaleBy))
+    | `Normalize(t) => "normalize(" ++ nodeToString(t) ++ ")"
+    | `FloatFromDist(floatFromDistOp, t) =>
+      DistToFloat.format(floatFromDistOp, nodeToString(t))
+    | `Truncate(lc, rc, t) => truncateToString(lc, rc, nodeToString(t))
+    | `Render(t) => nodeToString(t);
+};

src/distPlus/renderers/RenderTypes.re

@@ -43,7 +43,7 @@ module ShapeRenderer = {
   module Symbolic = {
     type inputs = {length: int};
     type outputs = {
-      graph: TreeNode.treeNode,
+      graph: ExpressionTypes.ExpressionTree.node,
       shape: DistTypes.shape,
     };
     let make = (graph, shape) => {graph, shape};

src/distPlus/renderers/ShapeRenderer.re

@@ -21,7 +21,7 @@ let runSymbolic = (guesstimatorString, length) => {
   |> E.R.fmap(g =>
        RenderTypes.ShapeRenderer.Symbolic.make(
          g,
-         TreeNode.toShape(length, g),
+         ExpressionTree.toShape(length, g),
        )
      );
 };

src/distPlus/symbolic/MathjsWrapper.js

@@ -1,8 +0,0 @@
-
-const math = require("mathjs");
-
-function parseMath(f){ return JSON.parse(JSON.stringify(math.parse(f))) };
-
-module.exports = {
-  parseMath,
-};

src/distPlus/symbolic/SymbolicDist.re

@@ -76,7 +76,7 @@ module Normal = {
     `Normal({mean, stdev});
   };
 
-  let operate = (operation: SymbolicTypes.Algebraic.t, n1: t, n2: t) =>
+  let operate = (operation: Operation.Algebraic.t, n1: t, n2: t) =>
     switch (operation) {
     | `Add => Some(add(n1, n2))
     | `Subtract => Some(subtract(n1, n2))
@@ -130,7 +130,7 @@ module Lognormal = {
     let sigma = l1.sigma +. l2.sigma;
     `Lognormal({mu, sigma});
   };
-  let operate = (operation: SymbolicTypes.Algebraic.t, n1: t, n2: t) =>
+  let operate = (operation: Operation.Algebraic.t, n1: t, n2: t) =>
     switch (operation) {
     | `Multiply => Some(multiply(n1, n2))
     | `Divide => Some(divide(n1, n2))
@@ -246,7 +246,7 @@ module T = {
     | `Uniform(n) => Uniform.mean(n)
     | `Float(n) => Float.mean(n);
 
-  let operate = (distToFloatOp: distToFloatOperation, s) =>
+  let operate = (distToFloatOp: ExpressionTypes.distToFloatOperation, s) =>
     switch (distToFloatOp) {
     | `Pdf(f) => Ok(pdf(f, s))
     | `Inv(f) => Ok(inv(f, s))
@@ -283,12 +283,12 @@ module T = {
       (
         d1: symbolicDist,
         d2: symbolicDist,
-        op: SymbolicTypes.algebraicOperation,
+        op: ExpressionTypes.algebraicOperation,
       )
       : analyticalSolutionAttempt =>
     switch (d1, d2) {
     | (`Float(v1), `Float(v2)) =>
-      switch (SymbolicTypes.Algebraic.applyFn(op, v1, v2)) {
+      switch (Operation.Algebraic.applyFn(op, v1, v2)) {
       | Ok(r) => `AnalyticalSolution(`Float(r))
       | Error(n) => `Error(n)
       }

src/distPlus/symbolic/SymbolicTypes.re

@@ -46,80 +46,4 @@ type symbolicDist = [
   | `Triangular(triangular)
   | `ContinuousShape(continuousShape)
   | `Float(float) // Dirac delta at x. Practically useful only in the context of multimodals.
-];
-
-// todo: These operations are really applicable for all dists
-type algebraicOperation = [ | `Add | `Multiply | `Subtract | `Divide];
-type pointwiseOperation = [ | `Add | `Multiply];
-type scaleOperation = [ | `Multiply | `Exponentiate | `Log];
-type distToFloatOperation = [ | `Pdf(float) | `Inv(float) | `Mean | `Sample];
-
-module Algebraic = {
-  type t = algebraicOperation;
-  let toFn: (t, float, float) => float =
-    fun
-    | `Add => (+.)
-    | `Subtract => (-.)
-    | `Multiply => ( *. )
-    | `Divide => (/.);
-
-  let applyFn = (t, f1, f2) => {
-    switch (t, f1, f2) {
-    | (`Divide, _, 0.) => Error("Cannot divide $v1 by zero.")
-    | _ => Ok(toFn(t, f1, f2))
-    };
-  };
-
-  let toString =
-    fun
-    | `Add => "+"
-    | `Subtract => "-"
-    | `Multiply => "*"
-    | `Divide => "/";
-
-  let format = (a, b, c) => b ++ " " ++ toString(a) ++ " " ++ c;
-};
-
-module Pointwise = {
-  type t = pointwiseOperation;
-  let toString =
-    fun
-    | `Add => "+"
-    | `Multiply => "*";
-
-  let format = (a, b, c) => b ++ " " ++ toString(a) ++ " " ++ c;
-};
-
-module DistToFloat = {
-  type t = distToFloatOperation;
-
-  let format = (operation, value) =>
-    switch (operation) {
-    | `Pdf(f) => {j|pdf(x=$f,$value)|j}
-    | `Inv(f) => {j|inv(x=$f,$value)|j}
-    | `Sample => "sample($value)"
-    | `Mean => "mean($value)"
-    };
-};
-
-module Scale = {
-  type t = scaleOperation;
-  let toFn =
-    fun
-    | `Multiply => ( *. )
-    | `Exponentiate => ( ** )
-    | `Log => ((a, b) => log(a) /. log(b));
-
-  let format = (operation:t, value, scaleBy) =>
-    switch (operation) {
-    | `Multiply => {j|scaleMultiply($value, $scaleBy) |j}
-    | `Exponentiate => {j|ScaleExponentiate($value, $scaleBy) |j}
-    | `Log => {j|ScaleLog($value, $scaleBy) |j}
-    };
-
-  let toKnownIntegralSumFn =
-    fun
-    | `Multiply => ((a, b) => Some(a *. b))
-    | `Exponentiate => ((_, _) => None)
-    | `Log => ((_, _) => None);
-};
+];

src/distPlus/symbolic/TreeNode.re

@@ -1,387 +0,0 @@
-/* This module represents a tree node. */
-open SymbolicTypes;
-
-type leaf = [
-  | `SymbolicDist(SymbolicTypes.symbolicDist)
-  | `RenderedDist(DistTypes.shape)
-];
-
-/* TreeNodes are either Data (i.e. symbolic or rendered distributions) or Operations. Operations always refer to two child nodes.*/
-type treeNode = [ | `Leaf(leaf) | `Operation(operation)]
-and operation = [
-  | `AlgebraicCombination(algebraicOperation, treeNode, treeNode)
-  | `PointwiseCombination(pointwiseOperation, treeNode, treeNode)
-  | `VerticalScaling(scaleOperation, treeNode, treeNode)
-  | `Render(treeNode)
-  | `Truncate(option(float), option(float), treeNode)
-  | `Normalize(treeNode)
-  | `FloatFromDist(distToFloatOperation, treeNode)
-];
-
-module Operation = {
-  type t = operation;
-  let truncateToString =
-      (left: option(float), right: option(float), nodeToString) => {
-    let left = left |> E.O.dimap(Js.Float.toString, () => "-inf");
-    let right = right |> E.O.dimap(Js.Float.toString, () => "inf");
-    {j|truncate($nodeToString, $left, $right)|j};
-  };
-
-  let toString = nodeToString =>
-    fun
-    | `AlgebraicCombination(op, t1, t2) =>
-      SymbolicTypes.Algebraic.format(op, nodeToString(t1), nodeToString(t2))
-    | `PointwiseCombination(op, t1, t2) =>
-      SymbolicTypes.Pointwise.format(op, nodeToString(t1), nodeToString(t2))
-    | `VerticalScaling(scaleOp, t, scaleBy) =>
-      SymbolicTypes.Scale.format(
-        scaleOp,
-        nodeToString(t),
-        nodeToString(scaleBy),
-      )
-    | `Normalize(t) => "normalize(" ++ nodeToString(t) ++ ")"
-    | `FloatFromDist(floatFromDistOp, t) =>
-      SymbolicTypes.DistToFloat.format(floatFromDistOp, nodeToString(t))
-    | `Truncate(lc, rc, t) => truncateToString(lc, rc, nodeToString(t))
-    | `Render(t) => nodeToString(t);
-};
-
-module TreeNode = {
-  type t = treeNode;
-  type tResult = treeNode => result(treeNode, string);
-
-  let rec toString =
-    fun
-    | `Leaf(`SymbolicDist(d)) => SymbolicDist.T.toString(d)
-    | `Leaf(`RenderedDist(_)) => "[shape]"
-    | `Operation(op) => Operation.toString(toString, op);
-
-  /* The following modules encapsulate everything we can do with
-   * different kinds of operations. */
-
-  /* Given two random variables A and B, this returns the distribution
-     of a new variable that is the result of the operation on A and B.
-     For instance, normal(0, 1) + normal(1, 1) -> normal(1, 2).
-     In general, this is implemented via convolution. */
-  module AlgebraicCombination = {
-    let toTreeNode = (op, t1, t2) =>
-      `Operation(`AlgebraicCombination((op, t1, t2)));
-    let tryAnalyticalSolution =
-      fun
-      | `Operation(
-          `AlgebraicCombination(
-            operation,
-            `Leaf(`SymbolicDist(d1)),
-            `Leaf(`SymbolicDist(d2)),
-          ),
-        ) as t =>
-        switch (SymbolicDist.T.attemptAnalyticalOperation(d1, d2, operation)) {
-        | `AnalyticalSolution(symbolicDist) =>
-          Ok(`Leaf(`SymbolicDist(symbolicDist)))
-        | `Error(er) => Error(er)
-        | `NoSolution => Ok(t)
-        }
-      | t => Ok(t);
-
-    // todo: I don't like the name evaluateNumerically that much, if this renders and does it algebraically. It's tricky.
-    let evaluateNumerically = (algebraicOp, operationToLeaf, t1, t2) => {
-      // force rendering into shapes
-      let renderShape = r => operationToLeaf(`Render(r));
-      switch (renderShape(t1), renderShape(t2)) {
-      | (Ok(`Leaf(`RenderedDist(s1))), Ok(`Leaf(`RenderedDist(s2)))) =>
-        Ok(
-          `Leaf(
-            `RenderedDist(
-              Distributions.Shape.combineAlgebraically(algebraicOp, s1, s2),
-            ),
-          ),
-        )
-      | (Error(e1), _) => Error(e1)
-      | (_, Error(e2)) => Error(e2)
-      | _ => Error("Could not render shapes.")
-      };
-    };
-
-    let toLeaf =
-        (
-          operationToLeaf,
-          algebraicOp: SymbolicTypes.algebraicOperation,
-          t1: t,
-          t2: t,
-        )
-        : result(treeNode, string) =>
-      toTreeNode(algebraicOp, t1, t2)
-      |> tryAnalyticalSolution
-      |> E.R.bind(
-           _,
-           fun
-           | `Leaf(d) => Ok(`Leaf(d)) // the analytical simplifaction worked, nice!
-           | `Operation(_) =>
-             // if not, run the convolution
-             evaluateNumerically(algebraicOp, operationToLeaf, t1, t2),
-         );
-  };
-
-  module VerticalScaling = {
-    let toLeaf = (operationToLeaf, scaleOp, t, scaleBy) => {
-      // scaleBy has to be a single float, otherwise we'll return an error.
-      let fn = SymbolicTypes.Scale.toFn(scaleOp);
-      let knownIntegralSumFn =
-        SymbolicTypes.Scale.toKnownIntegralSumFn(scaleOp);
-      let renderedShape = operationToLeaf(`Render(t));
-
-      switch (renderedShape, scaleBy) {
-      | (Ok(`Leaf(`RenderedDist(rs))), `Leaf(`SymbolicDist(`Float(sm)))) =>
-        Ok(
-          `Leaf(
-            `RenderedDist(
-              Distributions.Shape.T.mapY(
-                ~knownIntegralSumFn=knownIntegralSumFn(sm),
-                fn(sm),
-                rs,
-              ),
-            ),
-          ),
-        )
-      | (Error(e1), _) => Error(e1)
-      | (_, _) => Error("Can only scale by float values.")
-      };
-    };
-  };
-
-  module PointwiseCombination = {
-    let pointwiseAdd = (operationToLeaf, t1, t2) => {
-      let renderedShape1 = operationToLeaf(`Render(t1));
-      let renderedShape2 = operationToLeaf(`Render(t2));
-
-      switch (renderedShape1, renderedShape2) {
-      | (Ok(`Leaf(`RenderedDist(rs1))), Ok(`Leaf(`RenderedDist(rs2)))) =>
-        Ok(
-          `Leaf(
-            `RenderedDist(
-              Distributions.Shape.combinePointwise(
-                ~knownIntegralSumsFn=(a, b) => Some(a +. b),
-                (+.),
-                rs1,
-                rs2,
-              ),
-            ),
-          ),
-        )
-      | (Error(e1), _) => Error(e1)
-      | (_, Error(e2)) => Error(e2)
-      | _ => Error("Could not perform pointwise addition.")
-      };
-    };
-
-    let pointwiseMultiply = (operationToLeaf, t1, t2) => {
-      // TODO: construct a function that we can easily sample from, to construct
-      // a RenderedDist. Use the xMin and xMax of the rendered shapes to tell the sampling function where to look.
-      Error(
-        "Pointwise multiplication not yet supported.",
-      );
-    };
-
-    let toLeaf = (operationToLeaf, pointwiseOp, t1, t2) => {
-      switch (pointwiseOp) {
-      | `Add => pointwiseAdd(operationToLeaf, t1, t2)
-      | `Multiply => pointwiseMultiply(operationToLeaf, t1, t2)
-      };
-    };
-  };
-
-  module Truncate = {
-    module Simplify = {
-      let tryTruncatingNothing: tResult =
-        fun
-        | `Operation(`Truncate(None, None, `Leaf(d))) => Ok(`Leaf(d))
-        | t => Ok(t);
-
-      let tryTruncatingUniform: tResult =
-        fun
-        | `Operation(`Truncate(lc, rc, `Leaf(`SymbolicDist(`Uniform(u))))) => {
-            // just create a new Uniform distribution
-            let newLow = max(E.O.default(neg_infinity, lc), u.low);
-            let newHigh = min(E.O.default(infinity, rc), u.high);
-            Ok(
-              `Leaf(`SymbolicDist(`Uniform({low: newLow, high: newHigh}))),
-            );
-          }
-        | t => Ok(t);
-
-      let attempt = (leftCutoff, rightCutoff, t): result(treeNode, string) => {
-        let originalTreeNode =
-          `Operation(`Truncate((leftCutoff, rightCutoff, t)));
-
-        originalTreeNode
-        |> tryTruncatingNothing
-        |> E.R.bind(_, tryTruncatingUniform);
-      };
-    };
-
-    let evaluateNumerically = (leftCutoff, rightCutoff, operationToLeaf, t) => {
-      // TODO: use named args in renderToShape; if we're lucky we can at least get the tail
-      // of a distribution we otherwise wouldn't get at all
-      let renderedShape = operationToLeaf(`Render(t));
-
-      switch (renderedShape) {
-      | Ok(`Leaf(`RenderedDist(rs))) =>
-        let truncatedShape =
-          rs |> Distributions.Shape.T.truncate(leftCutoff, rightCutoff);
-        Ok(`Leaf(`RenderedDist(rs)));
-      | Error(e1) => Error(e1)
-      | _ => Error("Could not truncate distribution.")
-      };
-    };
-
-    let toLeaf =
-        (
-          operationToLeaf,
-          leftCutoff: option(float),
-          rightCutoff: option(float),
-          t: treeNode,
-        )
-        : result(treeNode, string) => {
-      t
-      |> Simplify.attempt(leftCutoff, rightCutoff)
-      |> E.R.bind(
-           _,
-           fun
-           | `Leaf(d) => Ok(`Leaf(d)) // the analytical simplifaction worked, nice!
-           | `Operation(_) =>
-             evaluateNumerically(leftCutoff, rightCutoff, operationToLeaf, t),
-         ); // if not, run the convolution
-    };
-  };
-
-  module Normalize = {
-    let rec toLeaf = (operationToLeaf, t: treeNode): result(treeNode, string) => {
-      switch (t) {
-      | `Leaf(`RenderedDist(s)) =>
-        Ok(`Leaf(`RenderedDist(Distributions.Shape.T.normalize(s))))
-      | `Leaf(`SymbolicDist(_)) => Ok(t)
-      | `Operation(op) =>
-        operationToLeaf(op) |> E.R.bind(_, toLeaf(operationToLeaf))
-      };
-    };
-  };
-
-  module FloatFromDist = {
-    let symbolicToLeaf = (distToFloatOp: distToFloatOperation, s) => {
-      SymbolicDist.T.operate(distToFloatOp, s)
-      |> E.R.bind(_, v => Ok(`Leaf(`SymbolicDist(`Float(v)))));
-    };
-    let renderedToLeaf =
-        (distToFloatOp: distToFloatOperation, rs: DistTypes.shape)
-        : result(treeNode, string) => {
-      Distributions.Shape.operate(distToFloatOp, rs)
-      |> (v => Ok(`Leaf(`SymbolicDist(`Float(v)))));
-    };
-    let rec toLeaf =
-            (
-              operationToLeaf,
-              distToFloatOp: distToFloatOperation,
-              t: treeNode,
-            )
-            : result(treeNode, string) => {
-      switch (t) {
-      | `Leaf(`SymbolicDist(s)) => symbolicToLeaf(distToFloatOp, s) // we want to evaluate the distToFloatOp on the symbolic dist
-      | `Leaf(`RenderedDist(rs)) => renderedToLeaf(distToFloatOp, rs)
-      | `Operation(op) =>
-        E.R.bind(
-          operationToLeaf(op),
-          toLeaf(operationToLeaf, distToFloatOp),
-        )
-      };
-    };
-  };
-
-  module Render = {
-    let rec toLeaf =
-            (
-              operationToLeaf: operation => result(t, string),
-              sampleCount: int,
-              t: treeNode,
-            )
-            : result(t, string) => {
-      switch (t) {
-      | `Leaf(`SymbolicDist(d)) =>
-        Ok(`Leaf(`RenderedDist(SymbolicDist.T.toShape(sampleCount, d))))
-      | `Leaf(`RenderedDist(_)) as t => Ok(t) // already a rendered shape, we're done here
-      | `Operation(op) =>
-        E.R.bind(operationToLeaf(op), toLeaf(operationToLeaf, sampleCount))
-      };
-    };
-  };
-
-  let rec operationToLeaf =
-          (sampleCount: int, op: operation): result(t, string) => {
-    // the functions that convert the Operation nodes to Leaf nodes need to
-    // have a way to call this function on their children, if their children are themselves Operation nodes.
-    switch (op) {
-    | `AlgebraicCombination(algebraicOp, t1, t2) =>
-      AlgebraicCombination.toLeaf(
-        operationToLeaf(sampleCount),
-        algebraicOp,
-        t1,
-        t2 // we want to give it the option to render or simply leave it as is
-      )
-    | `PointwiseCombination(pointwiseOp, t1, t2) =>
-      PointwiseCombination.toLeaf(
-        operationToLeaf(sampleCount),
-        pointwiseOp,
-        t1,
-        t2,
-      )
-    | `VerticalScaling(scaleOp, t, scaleBy) =>
-      VerticalScaling.toLeaf(
-        operationToLeaf(sampleCount),
-        scaleOp,
-        t,
-        scaleBy,
-      )
-    | `Truncate(leftCutoff, rightCutoff, t) =>
-      Truncate.toLeaf(
-        operationToLeaf(sampleCount),
-        leftCutoff,
-        rightCutoff,
-        t,
-      )
-    | `FloatFromDist(distToFloatOp, t) =>
-      FloatFromDist.toLeaf(operationToLeaf(sampleCount), distToFloatOp, t)
-    | `Normalize(t) => Normalize.toLeaf(operationToLeaf(sampleCount), t)
-    | `Render(t) =>
-      Render.toLeaf(operationToLeaf(sampleCount), sampleCount, t)
-    };
-  };
-
-  /* This function recursively goes through the nodes of the parse tree,
-     replacing each Operation node and its subtree with a Data node.
-     Whenever possible, the replacement produces a new Symbolic Data node,
-     but most often it will produce a RenderedDist.
-     This function is used mainly to turn a parse tree into a single RenderedDist
-     that can then be displayed to the user. */
-  let toLeaf = (treeNode: t, sampleCount: int): result(t, string) => {
-    switch (treeNode) {
-    | `Leaf(d) => Ok(`Leaf(d))
-    | `Operation(op) => operationToLeaf(sampleCount, op)
-    };
-  };
-};
-
-let toShape = (sampleCount: int, treeNode: treeNode) => {
-  let renderResult =
-    TreeNode.toLeaf(`Operation(`Render(treeNode)), sampleCount);
-
-  switch (renderResult) {
-  | Ok(`Leaf(`RenderedDist(rs))) =>
-    let continuous = Distributions.Shape.T.toContinuous(rs);
-    let discrete = Distributions.Shape.T.toDiscrete(rs);
-    let shape = MixedShapeBuilder.buildSimple(~continuous, ~discrete);
-    shape |> E.O.toExt("Could not build final shape.");
-  | Ok(_) => E.O.toExn("Rendering failed.", None)
-  | Error(message) => E.O.toExn("No shape found, error: " ++ message, None)
-  };
-};
-
-let toString = (treeNode: treeNode) => TreeNode.toString(treeNode);