Added simple exponentiation

src/distPlus/distribution/AlgebraicShapeCombination.re

@@ -45,11 +45,8 @@ let toDiscretePointMassesFromTriangulars =
 
   if (inverse) {
     for (i in 1 to n - 2) {
-      Belt.Array.set(
+      Belt.Array.set(masses, i - 1, (xs[i + 1] -. xs[i - 1]) *. ys[i] /. 2.)
-        masses,
+      |> ignore;
-        i - 1,
-        (xs[i + 1] -. xs[i - 1]) *. ys[i] /. 2.,
-      ) |> ignore;
 
       // this only works when the whole triange is either on the left or on the right of zero
       let a = xs[i - 1];
@@ -80,14 +77,12 @@ let toDiscretePointMassesFromTriangulars =
   } else {
     for (i in 1 to n - 2) {
       // area of triangle = width * height / 2
-      Belt.Array.set(
+      Belt.Array.set(masses, i - 1, (xs[i + 1] -. xs[i - 1]) *. ys[i] /. 2.)
-        masses,
+      |> ignore;
-        i - 1,
-        (xs[i + 1] -. xs[i - 1]) *. ys[i] /. 2.,
-      ) |> ignore;
 
       // means of triangle = (a + b + c) / 3
-      Belt.Array.set(means, i - 1, (xs[i - 1] +. xs[i] +. xs[i + 1]) /. 3.) |> ignore;
+      Belt.Array.set(means, i - 1, (xs[i - 1] +. xs[i] +. xs[i + 1]) /. 3.)
+      |> ignore;
 
       // variance of triangle = (a^2 + b^2 + c^2 - ab - ac - bc) / 18
       Belt.Array.set(
@@ -102,7 +97,8 @@ let toDiscretePointMassesFromTriangulars =
           -. xsProdN2[i - 1]
         )
         /. 18.,
-      ) |> ignore;
+      )
+      |> ignore;
       ();
     };
     {n: n - 2, masses, means, variances};
@@ -134,8 +130,10 @@ let combineShapesContinuousContinuous =
     | `Subtract => ((m1, m2) => m1 -. m2)
     | `Multiply => ((m1, m2) => m1 *. m2)
     | `Divide => ((m1, mInv2) => m1 *. mInv2)
+    | `Exponentiate => ((m1, mInv2) => m1 ** mInv2)
     }; // note: here, mInv2 = mean(1 / t2) ~= 1 / mean(t2)
 
+  // TODO: I don't know what the variances are for exponentatiation
   // converts the variances and means of the two inputs into the variance of the output
   let combineVariancesFn =
     switch (op) {
@@ -144,6 +142,8 @@ let combineShapesContinuousContinuous =
     | `Multiply => (
         (v1, v2, m1, m2) => v1 *. v2 +. v1 *. m2 ** 2. +. v2 *. m1 ** 2.
       )
+    | `Exponentiate =>
+      ((v1, v2, m1, m2) => v1 *. v2 +. v1 *. m2 ** 2. +. v2 *. m1 ** 2.);
     | `Divide => (
         (v1, vInv2, m1, mInv2) =>
           v1 *. vInv2 +. v1 *. mInv2 ** 2. +. vInv2 *. m1 ** 2.
@@ -225,9 +225,12 @@ let toDiscretePointMassesFromDiscrete =
 };
 
 let combineShapesContinuousDiscrete =
-    (op: ExpressionTypes.algebraicOperation, continuousShape: DistTypes.xyShape, discreteShape: DistTypes.xyShape)
+    (
+      op: ExpressionTypes.algebraicOperation,
+      continuousShape: DistTypes.xyShape,
+      discreteShape: DistTypes.xyShape,
+    )
     : DistTypes.xyShape => {
-
   let t1n = continuousShape |> XYShape.T.length;
   let t2n = discreteShape |> XYShape.T.length;
 
@@ -248,15 +251,19 @@ let combineShapesContinuousDiscrete =
         Belt.Array.set(
           dxyShape,
           i,
-          (fn(continuousShape.xs[i], discreteShape.xs[j]),
+          (
-          continuousShape.ys[i] *. discreteShape.ys[j]),
+            fn(continuousShape.xs[i], discreteShape.xs[j]),
-        ) |> ignore;
+            continuousShape.ys[i] *. discreteShape.ys[j],
+          ),
+        )
+        |> ignore;
         ();
       };
       Belt.Array.set(outXYShapes, j, dxyShape) |> ignore;
       ();
     }
   | `Multiply
+  | `Exponentiate
   | `Divide =>
     for (j in 0 to t2n - 1) {
       // creates a new continuous shape for each one of the discrete points, and collects them in outXYShapes.
@@ -266,8 +273,12 @@ let combineShapesContinuousDiscrete =
         Belt.Array.set(
           dxyShape,
           i,
-          (fn(continuousShape.xs[i], discreteShape.xs[j]), continuousShape.ys[i] *. discreteShape.ys[j] /. discreteShape.xs[j]),
+          (
-        ) |> ignore;
+            fn(continuousShape.xs[i], discreteShape.xs[j]),
+            {continuousShape.ys[i] *. discreteShape.ys[j] /. discreteShape.xs[j]}
+          ),
+        )
+        |> ignore;
         ();
       };
       Belt.Array.set(outXYShapes, j, dxyShape) |> ignore;
@@ -278,7 +289,10 @@ let combineShapesContinuousDiscrete =
   outXYShapes
   |> E.A.fmap(XYShape.T.fromZippedArray)
   |> E.A.fold_left(
-      XYShape.PointwiseCombination.combine((+.),
+       XYShape.PointwiseCombination.combine(
-                                           XYShape.XtoY.continuousInterpolator(`Linear, `UseZero)),
+         (+.),
-      XYShape.T.empty);
+         XYShape.XtoY.continuousInterpolator(`Linear, `UseZero),
+       ),
+       XYShape.T.empty,
+     );
 };

src/distPlus/expressionTree/ExpressionTreeEvaluator.re

@@ -151,7 +151,7 @@ module PointwiseCombination = {
     };
   };
 
-  let pointwiseMultiply = (evaluationParams: evaluationParams, t1: t, t2: t) => {
+  let pointwiseCombine = (fn, evaluationParams: evaluationParams, t1: t, t2: t) => {
     // 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.
     // TODO: This should work for symbolic distributions too!
@@ -176,7 +176,8 @@ module PointwiseCombination = {
       ) => {
     switch (pointwiseOp) {
     | `Add => pointwiseAdd(evaluationParams, t1, t2)
-    | `Multiply => pointwiseMultiply(evaluationParams, t1, t2)
+    | `Multiply => pointwiseCombine(( *. ),evaluationParams, t1, t2)
+    | `Exponentiate => pointwiseCombine(( *. ),evaluationParams, t1, t2)
     };
   };
 };
@@ -279,7 +280,7 @@ module Render = {
     | `SymbolicDist(d) =>
       Ok(
         `RenderedDist(
-          SymbolicDist.T.toShape(1234, d),
+          SymbolicDist.T.toShape(evaluationParams.samplingInputs.shapeLength, d),
         ),
       )
     | `RenderedDist(_) as t => Ok(t) // already a rendered shape, we're done here

src/distPlus/expressionTree/ExpressionTypes.re

@@ -1,5 +1,5 @@
-type algebraicOperation = [ | `Add | `Multiply | `Subtract | `Divide];
+type algebraicOperation = [ | `Add | `Multiply | `Subtract | `Divide | `Exponentiate];
-type pointwiseOperation = [ | `Add | `Multiply];
+type pointwiseOperation = [ | `Add | `Multiply | `Exponentiate];
 type scaleOperation = [ | `Multiply | `Exponentiate | `Log];
 type distToFloatOperation = [
   | `Pdf(float)

src/distPlus/expressionTree/MathJsParser.re

@@ -177,11 +177,12 @@ module MathAdtToDistDst = {
     };
   };
 
+          //  Error("Dotwise exponentiation needs two operands")
   let operationParser =
       (
         name: string,
         args: result(array(ExpressionTypes.ExpressionTree.node), string),
-      ) => {
+      ):result(ExpressionTypes.ExpressionTree.node,string) => {
     let toOkAlgebraic = r => Ok(`AlgebraicCombination(r));
     let toOkPointwise = r => Ok(`PointwiseCombination(r));
     let toOkTruncate = r => Ok(`Truncate(r));
@@ -195,6 +196,8 @@ module MathAdtToDistDst = {
          | ("subtract", _) => Error("Subtraction needs two operands")
          | ("multiply", [|l, r|]) => toOkAlgebraic((`Multiply, l, r))
          | ("multiply", _) => Error("Multiplication needs two operands")
+         | ("pow", [|l,r|]) => toOkAlgebraic((`Exponentiate, l, r))
+         | ("pow", _) => Error("Exponentiation needs two operands")
          | ("dotMultiply", [|l, r|]) => toOkPointwise((`Multiply, l, r))
          | ("dotMultiply", _) =>
            Error("Dotwise multiplication needs two operands")
@@ -203,7 +206,6 @@ module MathAdtToDistDst = {
            Error("Dotwise addition needs two operands")
          | ("divide", [|l, r|]) => toOkAlgebraic((`Divide, l, r))
          | ("divide", _) => Error("Division needs two operands")
-         | ("pow", _) => Error("Exponentiation is not yet supported.")
          | ("leftTruncate", [|d, `SymbolicDist(`Float(lc))|]) =>
            toOkTruncate((Some(lc), None, d))
          | ("leftTruncate", _) =>

src/distPlus/expressionTree/Operation.re

@@ -7,6 +7,7 @@ module Algebraic = {
     | `Add => (+.)
     | `Subtract => (-.)
     | `Multiply => ( *. )
+    | `Exponentiate => ( ** )
     | `Divide => (/.);
 
   let applyFn = (t, f1, f2) => {
@@ -21,6 +22,7 @@ module Algebraic = {
     | `Add => "+"
     | `Subtract => "-"
     | `Multiply => "*"
+    | `Exponentiate => ( "**" )
     | `Divide => "/";
 
   let format = (a, b, c) => b ++ " " ++ toString(a) ++ " " ++ c;

src/distPlus/renderers/DistPlusRenderer.re

@@ -125,7 +125,7 @@ module Internals = {
   let inputsToShape = (inputs: inputs) => {
     MathJsParser.fromString(inputs.guesstimatorString)
     |> E.R.bind(_, g => runProgram(inputs, g))
-    |> E.R.bind(_, r => E.A.last(r) |> E.O.toResult("No rendered lines"));
+    |> E.R.bind(_, r => E.A.last(r) |> E.O.toResult("No rendered lines") |> E.R.fmap(Shape.T.normalize));
   };
 
   let outputToDistPlus = (inputs: Inputs.inputs, shape: DistTypes.shape) => {