Futzing about with "symbolic function invocation" via sympy.

sympy_invoke.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [],
   "source": [
    "import sympy"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "import sympy.parsing.sympy_parser as sympy_parser"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [],
   "source": [
    "import inspect"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [],
   "source": [
    "s = inspect.signature(foo)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [],
   "source": [
    "def sympy_invoke(f):\n",
    "    \"\"\"Invoke function f with symbolic parameters.\"\"\"\n",
    "    fsig = inspect.signature(f)\n",
    "    pnames = tuple(fsig.parameters)\n",
    "    symbols = dict(zip(pnames, sympy.symbols(pnames)))\n",
    "    return f(**symbols)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [],
   "source": [
    "def lj(r, r_m, eps):\n",
    "    d = r_m / r\n",
    "    return eps * (d ** 12 - 2 * d ** 6)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "metadata": {},
   "outputs": [],
   "source": [
    "p = sympy_invoke(lj)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 50,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "eps*(12*r_m**6/r**7 - 12*r_m**12/r**13)"
      ]
     },
     "execution_count": 50,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "p.diff(sympy.symbols(\"r\"))"
   ]
  }
 ],
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