From 1c8400ab93e5073f7ddc53b09a1aaebd2df70dab Mon Sep 17 00:00:00 2001
From: Evgeny Metelkin <evgeny.metelkin@gmail.com>
Date: Mon, 15 Jul 2024 11:50:27 +0300
Subject: [PATCH] convert ln to log for matlab

---
 src/matlab-export/expression.js | 3 +++
 test/core/expression.js         | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/src/matlab-export/expression.js b/src/matlab-export/expression.js
index ea36893f..31500902 100644
--- a/src/matlab-export/expression.js
+++ b/src/matlab-export/expression.js
@@ -36,6 +36,9 @@ Expression.prototype.toMatlabString = function(substituteByDefinitions = true) {
     if (node.type==='FunctionNode' && node.fn.name==='log2') {
       return `(log(${node.args[0].toString(options)})/log(2))`;
     }
+    if (node.type==='FunctionNode' && node.fn.name==='ln') {
+      return `log(${node.args[0].toString(options)})`;
+    }
     if (node.type==='SymbolNode' && node.name === 't') {
       return 'time';
     }
diff --git a/test/core/expression.js b/test/core/expression.js
index 91426338..9485ec6a 100644
--- a/test/core/expression.js
+++ b/test/core/expression.js
@@ -162,4 +162,8 @@ describe('Expession exports', () => {
     let expr = Expression.fromString('exp(-kel*t)');
     expect(expr.toMatlabString()).to.be.equal('exp(-kel * time)');
   });
+  it('toMatlabString() for "ln(x)"', () => {
+    let expr = Expression.fromString('ln(x)');
+    expect(expr.toMatlabString()).to.be.equal('log(x)');
+  });
 });