feat: further progress, deal with parentheses

index.js

@@ -14,7 +14,9 @@ let isArgLognormal = (arg) => {
   let andNameIsLognormal = isFn && arg.fn.name == "lognormal";
   let andHasArgs = andNameIsLognormal && !!arg.args;
   let andHasTwoArgs = andHasArgs && arg.args.length == 2;
-  let andTwoArgsAreConstant = arg.args
+  let andTwoArgsAreConstant =
+    andHasTwoArgs &&
+    arg.args
       .map(
         (innerArg) => isConstantNode(innerArg)
         // innerArg
@@ -38,13 +40,26 @@ let createLogarithmNode = (mu, sigma) => {
 let transformerInner = (string) => {
   let nodes = math.parse(string);
   let transformed = nodes.transform(function (node, path, parent) {
+    // Multiplication
     if (node.type == "OperatorNode" && node.op == "*") {
-      let hasArgs = node.args && node.args.length == 2;
-      if (hasArgs) {
+      let hasTwoArgs = node.args && node.args.length == 2;
+      if (hasTwoArgs) {
+        console.log(JSON.stringify(node.args, null, 4));
+        // Multiplication of two lognormals
         let areArgsLognormal = node.args
           .map((arg) => isArgLognormal(arg))
           .reduce((a, b) => a && b, true);
+
+        let isFirstArgLognormal = isArgLognormal(node.args[0]);
+        let isSecondArgNumber = isConstantNode(node.args[1]);
+        let isLognormalTimesNumber = isFirstArgLognormal * isSecondArgNumber;
+
+        let isFirstArgNumber = isConstantNode(node.args[0]);
+        let isSecondArgLognormal = isArgLognormal(node.args[1]);
+        let isNumberTimesLognormal = isFirstArgNumber * isSecondArgLognormal;
+
         if (areArgsLognormal) {
+          // lognormal times lognormal
           let factors = node.args.map((arg) => getFactors(arg));
           let mean1 = factors[0][0];
           let std1 = factors[0][1];
@@ -54,19 +69,43 @@ let transformerInner = (string) => {
           let newMean = mean1 + mean2;
           let newStd = Math.sqrt(std1 ** 2 + std2 ** 2);
           return createLogarithmNode(newMean, newStd);
-          return new math.SymbolNode("xx");
-        } else {
-          return node;
+        } else if (isLognormalTimesNumber) {
+          // lognormal times number
+          let lognormalFactors = getFactors(node.args[0]);
+          let mean = lognormalFactors[0];
+          let std = lognormalFactors[1];
+          let multiplier = node.args[1].value;
+          let logMultiplier = Math.log(multiplier);
+          let newMean = mean + logMultiplier;
+          return createLogarithmNode(newMean, std);
+        } else if (isNumberTimesLognormal) {
+          // number times lognormal
+          let lognormalFactors = getFactors(node.args[1]);
+          let mean = lognormalFactors[0];
+          let std = lognormalFactors[1];
+          let multiplier = node.args[0].value;
+          let logMultiplier = Math.log(multiplier);
+          let newMean = mean + logMultiplier;
+          return createLogarithmNode(newMean, std);
         }
-      } else {
-        return node;
       }
     } else if (node.type == "OperatorNode" && node.op == "/") {
-      let hasArgs = node.args && node.args.length == 2;
-      if (hasArgs) {
+      let hasTwoArgs = node.args && node.args.length == 2;
+      if (hasTwoArgs) {
         let areArgsLognormal = node.args
           .map((arg) => isArgLognormal(arg))
           .reduce((a, b) => a && b, true);
+
+        let isFirstArgLognormal = isArgLognormal(node.args[0]);
+        let isSecondArgNumber = isConstantNode(node.args[1]);
+        let isLognormalDividedByNumber =
+          isFirstArgLognormal * isSecondArgNumber;
+
+        let isFirstArgNumber = isConstantNode(node.args[0]);
+        let isSecondArgLognormal = isArgLognormal(node.args[1]);
+        let isNumberDividedByLognormal =
+          isFirstArgNumber * isSecondArgLognormal;
+
         if (areArgsLognormal) {
           let factors = node.args.map((arg) => getFactors(arg));
           let mean1 = factors[0][0];
@@ -78,9 +117,34 @@ let transformerInner = (string) => {
           let newStd = Math.sqrt(std1 ** 2 + std2 ** 2);
           return createLogarithmNode(newMean, newStd);
           return new math.SymbolNode("xx");
+        } else if (isLognormalDividedByNumber) {
+          let lognormalFactors = getFactors(node.args[0]);
+          let mean = lognormalFactors[0];
+          let std = lognormalFactors[1];
+          let multiplier = node.args[1].value;
+          let logMultiplier = Math.log(multiplier);
+          let newMean = mean - logMultiplier;
+          return createLogarithmNode(newMean, std);
+        } else if (isNumberDividedByLognormal) {
+          let lognormalFactors = getFactors(node.args[1]);
+          let mean = lognormalFactors[0];
+          let std = lognormalFactors[1];
+          let multiplier = node.args[0].value;
+          let logMultiplier = Math.log(multiplier);
+          let newMean = -mean + logMultiplier;
+          return createLogarithmNode(newMean, std);
         }
       }
     }
+    if (node.type == "ParenthesisNode") {
+      if (
+        !!node.content &&
+        !!node.content.fn &&
+        node.content.fn.name == "lognormal"
+      ) {
+        return node.content;
+      }
+    }
     return node;
   });
 
@@ -146,12 +210,55 @@ let testTransformer = (string) => {
 };
 
 // Defs
-let tests = [
+let tests1 = [
   `lognormal(1,10) * lognormal(1,10) + lognormal(1,10)`,
   `lognormal(1,10) * lognormal(1,10) * lognormal(1,10)`,
   `1 to 10 * lognormal(1, 10)`,
   `lognormal(1, 10) * 1 to 20`,
   `1 to 20 * 100 to 1000`,
+  `(lognormal(1,10) / lognormal(1,10)) + lognormal(1,10)`,
+  `lognormal(1,10) * lognormal(1,10) / lognormal(1,10)`,
+  `1 to 10 * lognormal(1, 10) / 1 to 10`,
+  `lognormal(1, 10) * 1 to 20 / 1 to 20`,
+  `1 to 20 * 100 to 1000 / 1 to 100`,
 ];
+let runTests1 = false;
+if (runTests1) {
   console.clear();
   tests.forEach((test) => testTransformer(test));
+}
+
+let tests2 = [
+  `3 * lognormal(1,10)`,
+  `lognormal(1,10) * 4`,
+  `lognormal(1, 10) / 3`,
+  `3 / lognormal(1, 10)`,
+  `lognormal(1,10) * lognormal(1/10) / 3`,
+  `lognormal(1, 10) / (1 to 3)`,
+];
+
+let runTests2 = false;
+if (runTests2) {
+  console.clear();
+  tests2.forEach((test) => testTransformer(test));
+}
+
+let tests3 = [
+  `(lognormal(1,10))`,
+  `lognormal(1,10) * (lognormal(1, 10) * 3) / (4 * lognormal(1,10))`,
+];
+let runTests3 = false;
+if (runTests3) {
+  console.clear();
+  tests3.forEach((test) => testTransformer(test));
+}
+
+let tests4 = [
+  `(1 to 2) * 3 * lognormal(1,10) * (1/lognormal(1,10)) / (1 to 10)`,
+  `lognormal(2.4451858789480823, 10.002219515733781) * lognormal(-1, 10) `,
+];
+let runTests4 = true;
+if (runTests4) {
+  console.clear();
+  tests4.forEach((test) => testTransformer(test));
+}