From 5c3a3d2bdf88e31d4197d92c5288e1d84490de2f Mon Sep 17 00:00:00 2001
From: Shah Mahdi Hasan <tanweer.mahdi@gmail.com>
Date: Mon, 27 Nov 2023 09:57:12 +1100
Subject: [PATCH] Added "round" operator in the Sympy mappings

Enabling a workaround to avoid the following type error:

`raise TypeError("Cannot round symbolic expression")`

while using `round` as a unary operator.

This issue was raised in #269 the the PR contains the exact solution put forth in the subsequent discussion
---
 pysr/export_sympy.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pysr/export_sympy.py b/pysr/export_sympy.py
index e10609bde..3c3c5f931 100644
--- a/pysr/export_sympy.py
+++ b/pysr/export_sympy.py
@@ -49,6 +49,7 @@
     "gamma": sympy.gamma,
     "max": lambda x, y: sympy.Piecewise((y, x < y), (x, True)),
     "min": lambda x, y: sympy.Piecewise((x, x < y), (y, True)),
+    "round": lambda x: sympy.ceiling(x - 0.5),
 }