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    "# mathmoreIntegrationMultidim\n",
    "Example on the usage of the multidimensional integration algorithm of MathMore.\n",
    "\n",
    "Please refer to the web documentation for further details: \n",
    "     https://root.cern/manual/math/#numerical-integration\n",
    "To execute the macro type the following:\n",
    "\n",
    "```cpp\n",
    "root[0] .x mathmoreIntegrationMultidim.C\n",
    "```\n",
    "\n",
    "This tutorial requires having libMathMore built with ROOT.\n",
    "\n",
    "To build mathmore you need to have a version of GSL >= 1.8 installed in your system\n",
    "The ROOT configure will automatically find GSL if the script gsl-config (from GSL) is in your PATH,.\n",
    "otherwise you need to configure root with the options --gsl-incdir and --gsl-libdir.\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Author:**  A. Tolosa-Delgado  \n",
    "<i><small>This notebook tutorial was automatically generated with <a href= \"https://github.com/root-project/root/blob/master/documentation/doxygen/converttonotebook.py\">ROOTBOOK-izer</a> from the macro found in the ROOT repository  on Tuesday, May 19, 2026 at 08:25 PM.</small></i>"
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   "source": [
    " Definition of a helper function: "
   ]
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   "source": [
    "%%cpp -d\n",
    "\n",
    "double f2(const double * x) {\n",
    "   return x[0] + x[1];\n",
    "}"
   ]
  },
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    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "integral result is 1\n",
      "integral result is 0.999998\n",
      "integral result is 0.999738\n",
      "integral result is 0.999881\n"
     ]
    }
   ],
   "source": [
    "const double RESULT = 1.0;\n",
    "const double ERRORLIMIT = 1E-3;\n",
    "int status = 0;\n",
    "\n",
    "ROOT::Math::Functor wf(&f2,2);\n",
    "double a[2] = {0,0};\n",
    "double b[2] = {1,1};\n",
    "\n",
    "ROOT::Math::IntegratorMultiDim ig(ROOT::Math::IntegrationMultiDim::kADAPTIVE);\n",
    "ig.SetFunction(wf);\n",
    "double val = ig.Integral(a,b);\n",
    "std::cout << \"integral result is \" << val << std::endl;\n",
    "status += std::fabs(val-RESULT) > ERRORLIMIT;\n",
    "\n",
    "ROOT::Math::IntegratorMultiDim ig2(ROOT::Math::IntegrationMultiDim::kVEGAS);\n",
    "ig2.SetFunction(wf);\n",
    "val = ig2.Integral(a,b);\n",
    "std::cout << \"integral result is \" << val << std::endl;\n",
    "status += std::fabs(val-RESULT) > ERRORLIMIT;\n",
    "\n",
    "ROOT::Math::IntegratorMultiDim ig3(wf,ROOT::Math::IntegrationMultiDim::kPLAIN);\n",
    "val = ig3.Integral(a,b);\n",
    "std::cout << \"integral result is \" << val << std::endl;\n",
    "status += std::fabs(val-RESULT) > ERRORLIMIT;\n",
    "\n",
    "ROOT::Math::IntegratorMultiDim ig4(wf,ROOT::Math::IntegrationMultiDim::kMISER);\n",
    "val = ig4.Integral(a,b);\n",
    "std::cout << \"integral result is \" << val << std::endl;\n",
    "status += std::fabs(val-RESULT) > ERRORLIMIT;\n",
    "\n",
    "return status;"
   ]
  }
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