Merge pull request #49 from pie-framework/feat/PD-302

feat(PD-302): add log and sqrt rules

Author: CarlaCostea

src/conversion/ast-to-mathjs.ts

@@ -167,7 +167,7 @@ export class AstToMathJs {
           this.convert(operands[1]),
         ]);
 
-      const f = new m.SymbolNode(operands[0]);
+      const f = operands[0]
       const args = operands[1];
       let f_args;
 

src/fixtures/latex-equal/symbolic/PD-302.ts

@@ -0,0 +1,31 @@
+export default {
+  mode: "symbolic",
+  tests: [
+    {
+      target: "\\log(x*y)",
+      eq: [
+        "\\log(x)+\\log(y)",
+        "\\log_{10}(x)+\\log_{10}(y)",
+        "\\log_{10}(x*y)",
+      ],
+      ne: ["\\log_{10}(x)", "\\log(a*b)"],
+    },
+    {
+      target: "\\log(x/y)",
+      eq: [
+        "\\log(x)-\\log(y)",
+        "\\log_{10}(x)-\\log_{10}(y)",
+        "\\log_{10}(x/y)",
+      ],
+      ne: ["\\log_{10}(x)", "\\log(a/b)"],
+    },
+    {
+      target: "\\log(x^y)",
+      eq: ["y\\log(x)", "y\\log_{10}(x)", "\\log_{10}(x^y)"],
+    },
+    {
+      target: "\\sqrt(-1)",
+      eq: ["i"],
+    },
+  ],
+};

src/symbolic/index.ts

@@ -17,6 +17,7 @@ const { simplify: ms, rationalize } = mathjs;
 const SIMPLIFY_RULES = [
   { l: "n1^(1/n2)", r: "nthRoot(n1, n2)" },
   { l: "sqrt(n1)", r: "nthRoot(n1, 2)" },
+  { l: "nthRoot(-1, 2)", r: "i" },
   { l: "(v1-v2)/n", r: "v1/n-v2/n" },
   { l: "(v1-n)/n", r: "v1/n-1" },
   { l: "n/n1-c1", r: "(n-c1*n1)/n1" },
@@ -33,6 +34,11 @@ const SIMPLIFY_RULES = [
   { l: "n1/(-n2)", r: "-(n1/n2)" },
   { l: "sin(n*pi)", r: "0" },
 
+  // logarithm rules
+  { l: "log(n1*n2, n3)", r: "log(n1, n3)+log(n2,n3)" },
+  { l: "log(n1/n2, n3)", r: "log(n1, n3)-log(n2,n3)" },
+  { l: "log(n1^n2, n3)", r: "n2*log(n1,n3)" },
+
   // trigonometry: defining relations for tangent, cotangent, secant, and cosecant in terms of sine and cosine
   { l: "sin(n)/cos(n)", r: "tan(n)" },
   { l: "csc(n)", r: "1/sin(n)" },
@@ -167,7 +173,6 @@ export const isMathEqual = (a: any, b: any) => {
   let bs: MathNode;
 
   // apply sort if we are not in a relationalNode
-
   as = a.conditionals ? normalize(a) : sort(normalize(a));
 
   bs = b.conditionals ? normalize(b) : sort(normalize(b));