{ "cells": [ { "cell_type": "code", "execution_count": 1, "id": "c37ca5d1", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:42:49.479076Z", "iopub.status.busy": "2026-10-02T14:42:49.478826Z", "iopub.status.idle": "2026-10-02T14:42:49.483651Z", "shell.execute_reply": "2026-10-02T14:42:49.483009Z" }, "papermill": { "duration": 0.008096, "end_time": "2026-10-02T14:42:49.484487+00:00", "exception": false, "start_time": "2026-10-02T14:42:49.476391+00:00", "status": "completed" }, "tags": [ "remove-input", "active-ipynb", "remove-output" ] }, "outputs": [], "source": [ "try:\n", " from openmdao.utils.notebook_utils import notebook_mode # noqa: F401\n", "except ImportError:\n", " !python -m pip install openmdao[notebooks]" ] }, { "cell_type": "markdown", "id": "ef06cc2b", "metadata": { "papermill": { "duration": 0.001026, "end_time": "2026-10-02T14:42:49.486894+00:00", "exception": false, "start_time": "2026-10-02T14:42:49.485868+00:00", "status": "completed" }, "tags": [] }, "source": [ "# NonlinearRunOnce\n", "\n", "The simplest solver in OpenMDAO is NonlinearRunOnce, which executes the\n", "system's components or subsystems sequentially. No iteration is performed by\n", "this solver, so it can only be used in systems where the following conditions\n", "are satisfied:\n", "\n", "1. System does not contain a cycle, though subsystems may.\n", "2. System does not contain any implicit states, though subsystems may.\n", "\n", "Note that a subsystem may contain cycles or implicit states provided that it is\n", "fitted with a solver that can handle them such as [NewtonSolver](../../../_srcdocs/packages/solvers.nonlinear/newton).\n", "\n", "Here is an example of using NonlinearRunOnce for a simple model with the `Paraboloid` component." ] }, { "cell_type": "code", "execution_count": 2, "id": "76b185db", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:42:49.497782Z", "iopub.status.busy": "2026-10-02T14:42:49.497581Z", "iopub.status.idle": "2026-10-02T14:42:51.604247Z", "shell.execute_reply": "2026-10-02T14:42:51.603200Z" }, "papermill": { "duration": 2.11685, "end_time": "2026-10-02T14:42:51.604770+00:00", "exception": false, "start_time": "2026-10-02T14:42:49.487920+00:00", "status": "completed" }, "tags": [ "remove-input", "remove-output" ] }, "outputs": [ { "data": { "application/papermill.record/text/html": "
class Paraboloid(om.ExplicitComponent):\n    """\n    Evaluates the equation f(x,y) = (x-3)^2 + xy + (y+4)^2 - 3.\n    """\n\n    def setup(self):\n        self.add_input('x', val=0.0)\n        self.add_input('y', val=0.0)\n\n        self.add_output('f_xy', val=0.0)\n\n    def setup_partials(self):\n        self.declare_partials('*', '*')\n\n    def compute(self, inputs, outputs):\n        """\n        f(x,y) = (x-3)^2 + xy + (y+4)^2 - 3\n\n        Optimal solution (minimum): x = 6.6667; y = -7.3333\n        """\n        x = inputs['x']\n        y = inputs['y']\n\n        outputs['f_xy'] = (x-3.0)**2 + x*y + (y+4.0)**2 - 3.0\n\n    def compute_partials(self, inputs, partials):\n        """\n        Jacobian for our paraboloid.\n        """\n        x = inputs['x']\n        y = inputs['y']\n\n        partials['f_xy', 'x'] = 2.0*x - 6.0 + y\n        partials['f_xy', 'y'] = 2.0*y + 8.0 + x\n
\n", "application/papermill.record/text/latex": "\\begin{Verbatim}[commandchars=\\\\\\{\\}]\n\\PY{k}{class}\\PY{+w}{ }\\PY{n+nc}{Paraboloid}\\PY{p}{(}\\PY{n}{om}\\PY{o}{.}\\PY{n}{ExplicitComponent}\\PY{p}{)}\\PY{p}{:}\n\\PY{+w}{ }\\PY{l+s+sd}{\\PYZdq{}\\PYZdq{}\\PYZdq{}}\n\\PY{l+s+sd}{ Evaluates the equation f(x,y) = (x\\PYZhy{}3)\\PYZca{}2 + xy + (y+4)\\PYZca{}2 \\PYZhy{} 3.}\n\\PY{l+s+sd}{ \\PYZdq{}\\PYZdq{}\\PYZdq{}}\n\n \\PY{k}{def}\\PY{+w}{ }\\PY{n+nf}{setup}\\PY{p}{(}\\PY{n+nb+bp}{self}\\PY{p}{)}\\PY{p}{:}\n \\PY{n+nb+bp}{self}\\PY{o}{.}\\PY{n}{add\\PYZus{}input}\\PY{p}{(}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{x}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{n}{val}\\PY{o}{=}\\PY{l+m+mf}{0.0}\\PY{p}{)}\n \\PY{n+nb+bp}{self}\\PY{o}{.}\\PY{n}{add\\PYZus{}input}\\PY{p}{(}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{y}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{n}{val}\\PY{o}{=}\\PY{l+m+mf}{0.0}\\PY{p}{)}\n\n \\PY{n+nb+bp}{self}\\PY{o}{.}\\PY{n}{add\\PYZus{}output}\\PY{p}{(}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{f\\PYZus{}xy}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{n}{val}\\PY{o}{=}\\PY{l+m+mf}{0.0}\\PY{p}{)}\n\n \\PY{k}{def}\\PY{+w}{ }\\PY{n+nf}{setup\\PYZus{}partials}\\PY{p}{(}\\PY{n+nb+bp}{self}\\PY{p}{)}\\PY{p}{:}\n \\PY{n+nb+bp}{self}\\PY{o}{.}\\PY{n}{declare\\PYZus{}partials}\\PY{p}{(}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{*}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{*}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{)}\n\n \\PY{k}{def}\\PY{+w}{ }\\PY{n+nf}{compute}\\PY{p}{(}\\PY{n+nb+bp}{self}\\PY{p}{,} \\PY{n}{inputs}\\PY{p}{,} \\PY{n}{outputs}\\PY{p}{)}\\PY{p}{:}\n\\PY{+w}{ }\\PY{l+s+sd}{\\PYZdq{}\\PYZdq{}\\PYZdq{}}\n\\PY{l+s+sd}{ f(x,y) = (x\\PYZhy{}3)\\PYZca{}2 + xy + (y+4)\\PYZca{}2 \\PYZhy{} 3}\n\n\\PY{l+s+sd}{ Optimal solution (minimum): x = 6.6667; y = \\PYZhy{}7.3333}\n\\PY{l+s+sd}{ \\PYZdq{}\\PYZdq{}\\PYZdq{}}\n \\PY{n}{x} \\PY{o}{=} \\PY{n}{inputs}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{x}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]}\n \\PY{n}{y} \\PY{o}{=} \\PY{n}{inputs}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{y}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]}\n\n \\PY{n}{outputs}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{f\\PYZus{}xy}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]} \\PY{o}{=} \\PY{p}{(}\\PY{n}{x}\\PY{o}{\\PYZhy{}}\\PY{l+m+mf}{3.0}\\PY{p}{)}\\PY{o}{*}\\PY{o}{*}\\PY{l+m+mi}{2} \\PY{o}{+} \\PY{n}{x}\\PY{o}{*}\\PY{n}{y} \\PY{o}{+} \\PY{p}{(}\\PY{n}{y}\\PY{o}{+}\\PY{l+m+mf}{4.0}\\PY{p}{)}\\PY{o}{*}\\PY{o}{*}\\PY{l+m+mi}{2} \\PY{o}{\\PYZhy{}} \\PY{l+m+mf}{3.0}\n\n \\PY{k}{def}\\PY{+w}{ }\\PY{n+nf}{compute\\PYZus{}partials}\\PY{p}{(}\\PY{n+nb+bp}{self}\\PY{p}{,} \\PY{n}{inputs}\\PY{p}{,} \\PY{n}{partials}\\PY{p}{)}\\PY{p}{:}\n\\PY{+w}{ }\\PY{l+s+sd}{\\PYZdq{}\\PYZdq{}\\PYZdq{}}\n\\PY{l+s+sd}{ Jacobian for our paraboloid.}\n\\PY{l+s+sd}{ \\PYZdq{}\\PYZdq{}\\PYZdq{}}\n \\PY{n}{x} \\PY{o}{=} \\PY{n}{inputs}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{x}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]}\n \\PY{n}{y} \\PY{o}{=} \\PY{n}{inputs}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{y}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]}\n\n \\PY{n}{partials}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{f\\PYZus{}xy}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{x}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]} \\PY{o}{=} \\PY{l+m+mf}{2.0}\\PY{o}{*}\\PY{n}{x} \\PY{o}{\\PYZhy{}} \\PY{l+m+mf}{6.0} \\PY{o}{+} \\PY{n}{y}\n \\PY{n}{partials}\\PY{p}{[}\\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{f\\PYZus{}xy}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{,} \\PY{l+s+s1}{\\PYZsq{}}\\PY{l+s+s1}{y}\\PY{l+s+s1}{\\PYZsq{}}\\PY{p}{]} \\PY{o}{=} \\PY{l+m+mf}{2.0}\\PY{o}{*}\\PY{n}{y} \\PY{o}{+} \\PY{l+m+mf}{8.0} \\PY{o}{+} \\PY{n}{x}\n\\end{Verbatim}\n", "application/papermill.record/text/plain": "class Paraboloid(om.ExplicitComponent):\n \"\"\"\n Evaluates the equation f(x,y) = (x-3)^2 + xy + (y+4)^2 - 3.\n \"\"\"\n\n def setup(self):\n self.add_input('x', val=0.0)\n self.add_input('y', val=0.0)\n\n self.add_output('f_xy', val=0.0)\n\n def setup_partials(self):\n self.declare_partials('*', '*')\n\n def compute(self, inputs, outputs):\n \"\"\"\n f(x,y) = (x-3)^2 + xy + (y+4)^2 - 3\n\n Optimal solution (minimum): x = 6.6667; y = -7.3333\n \"\"\"\n x = inputs['x']\n y = inputs['y']\n\n outputs['f_xy'] = (x-3.0)**2 + x*y + (y+4.0)**2 - 3.0\n\n def compute_partials(self, inputs, partials):\n \"\"\"\n Jacobian for our paraboloid.\n \"\"\"\n x = inputs['x']\n y = inputs['y']\n\n partials['f_xy', 'x'] = 2.0*x - 6.0 + y\n partials['f_xy', 'y'] = 2.0*y + 8.0 + x" }, "metadata": { "scrapbook": { "mime_prefix": "application/papermill.record/", "name": "code_src38" } }, "output_type": "display_data" } ], "source": [ "from openmdao.utils.notebook_utils import get_code\n", "from myst_nb import glue\n", "glue(\"code_src38\", get_code(\"openmdao.test_suite.components.paraboloid.Paraboloid\"), display=False)" ] }, { "cell_type": "markdown", "id": "db3c2b33", "metadata": { "papermill": { "duration": 0.000907, "end_time": "2026-10-02T14:42:51.606828+00:00", "exception": false, "start_time": "2026-10-02T14:42:51.605921+00:00", "status": "completed" }, "tags": [] }, "source": [ ":::{dropdown} `Paraboloid` class definition \n", "\n", "{glue:}`code_src38`\n", ":::" ] }, { "cell_type": "code", "execution_count": 3, "id": "53abb6e3", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:42:51.609285Z", "iopub.status.busy": "2026-10-02T14:42:51.609115Z", "iopub.status.idle": "2026-10-02T14:42:52.877500Z", "shell.execute_reply": "2026-10-02T14:42:52.876595Z" }, "papermill": { "duration": 1.270967, "end_time": "2026-10-02T14:42:52.878716+00:00", "exception": false, "start_time": "2026-10-02T14:42:51.607749+00:00", "status": "completed" }, "tags": [] }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "[1790952172.834881] [runnervm8df0l:7343 :0] ib_iface.c:1269 UCX ERROR mana_0: iface 0x55f8bf0d6c80 failed to create UD QP TX wr:256 sge:6 inl:64 resp:0 RX wr:4096 sge:1 resp:0 failed: Operation not supported\n", "[1790952172.835128] [runnervm8df0l:7343 :0] ucp_worker.c:1412 UCX ERROR uct_iface_open(ud_verbs/mana_0:1) failed: Input/output error\n", "[[-6.]]\n", "[[8.]]\n" ] }, { "name": "stderr", "output_type": "stream", "text": [ "[runnervm8df0l:07343] pml_ucx.c:313 Error: Failed to create UCP worker\n" ] } ], "source": [ "import openmdao.api as om\n", "from openmdao.test_suite.components.paraboloid import Paraboloid\n", "\n", "prob = om.Problem()\n", "model = prob.model\n", "\n", "model.add_subsystem('comp', Paraboloid(), promotes=['x', 'y', 'f_xy'])\n", "\n", "model.linear_solver = om.LinearRunOnce()\n", "\n", "prob.setup(check=False, mode='fwd')\n", "\n", "prob.set_val('x', 0.0)\n", "prob.set_val('y', 0.0)\n", "\n", "prob.run_model()\n", "\n", "of = ['f_xy']\n", "wrt = ['x', 'y']\n", "derivs = prob.compute_totals(of=of, wrt=wrt, return_format='dict')\n", "\n", "print(derivs['f_xy']['x'])\n", "print(derivs['f_xy']['y'])" ] }, { "cell_type": "code", "execution_count": 4, "id": "86f434ac", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:42:52.882997Z", "iopub.status.busy": "2026-10-02T14:42:52.882679Z", "iopub.status.idle": "2026-10-02T14:42:52.887741Z", "shell.execute_reply": "2026-10-02T14:42:52.887047Z" }, "papermill": { "duration": 0.00791, "end_time": "2026-10-02T14:42:52.888352+00:00", "exception": false, "start_time": "2026-10-02T14:42:52.880442+00:00", "status": "completed" }, "tags": [ "remove-input", "remove-output" ] }, "outputs": [ { "data": { "text/plain": [ "np.float64(0.0)" ] }, "execution_count": 4, "metadata": {}, "output_type": "execute_result" } ], "source": [ "from openmdao.utils.assert_utils import assert_near_equal\n", "\n", "assert_near_equal(derivs['f_xy']['x'], [[-6.0]], 1e-6)\n", "assert_near_equal(derivs['f_xy']['y'], [[8.0]], 1e-6)" ] }, { "cell_type": "markdown", "id": "db02a9e0", "metadata": { "papermill": { "duration": 0.000971, "end_time": "2026-10-02T14:42:52.890431+00:00", "exception": false, "start_time": "2026-10-02T14:42:52.889460+00:00", "status": "completed" }, "tags": [] }, "source": [ "## NonlinearRunOnce Options" ] }, { "cell_type": "code", "execution_count": 5, "id": "2daed473", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:42:52.893046Z", "iopub.status.busy": "2026-10-02T14:42:52.892921Z", "iopub.status.idle": "2026-10-02T14:42:52.896216Z", "shell.execute_reply": "2026-10-02T14:42:52.895719Z" }, "papermill": { "duration": 0.005241, "end_time": "2026-10-02T14:42:52.896659+00:00", "exception": false, "start_time": "2026-10-02T14:42:52.891418+00:00", "status": "completed" }, "tags": [ "remove-input" ] }, "outputs": [ { "data": { "text/html": [ "\n", "\n", "\n", "\n", " \n", "\n", "\n", "

\n", " \n", " \n", " \n", " \n", "
OptionDefaultAcceptable ValuesAcceptable TypesDescription
debug_printFalse[True, False]['bool']If True, the values of input and output variables at the start of iteration are printed and written to a file after a failure to converge or when encountering aninvalid value in the residual.
iprint1N/A['int']whether to print output
\n", "\n", "\n" ], "text/plain": [ "" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "om.show_options_table(\"openmdao.solvers.nonlinear.nonlinear_runonce.NonlinearRunOnce\")" ] }, { "cell_type": "markdown", "id": "74953391", "metadata": { "papermill": { "duration": 0.001268, "end_time": "2026-10-02T14:42:52.898958+00:00", "exception": false, "start_time": "2026-10-02T14:42:52.897690+00:00", "status": "completed" }, "tags": [] }, "source": [ "## NonlinearRunOnce Constructor\n", "\n", "The call signature for the `NonlinearRunOnce` constructor is:\n", "\n", "```{eval-rst}\n", " .. automethod:: openmdao.solvers.nonlinear.nonlinear_runonce.NonlinearRunOnce.__init__\n", " :noindex:\n", "```" ] } ], "metadata": { "celltoolbar": "Tags", "kernelspec": { "display_name": "Python 3", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.13.14" }, "orphan": true, "papermill": { "default_parameters": {}, "duration": 4.648586, "end_time": "2026-10-02T14:42:53.514306+00:00", "environment_variables": {}, "exception": null, "input_path": "/home/runner/work/OpenMDAO/OpenMDAO/openmdao/docs/openmdao_book/features/building_blocks/solvers/nonlinear_runonce.ipynb", "output_path": "/home/runner/work/OpenMDAO/OpenMDAO/openmdao/docs/_executed_book/features/building_blocks/solvers/nonlinear_runonce.ipynb", "parameters": {}, "start_time": "2026-10-02T14:42:48.865720+00:00", "version": "2.7.0" } }, "nbformat": 4, "nbformat_minor": 5 }