{ "cells": [ { "cell_type": "code", "execution_count": 1, "id": "523e70f1", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:41:09.489200Z", "iopub.status.busy": "2026-10-02T14:41:09.488975Z", "iopub.status.idle": "2026-10-02T14:41:09.494118Z", "shell.execute_reply": "2026-10-02T14:41:09.493527Z" }, "papermill": { "duration": 0.008412, "end_time": "2026-10-02T14:41:09.495168+00:00", "exception": false, "start_time": "2026-10-02T14:41:09.486756+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]" ] }, { "attachments": {}, "cell_type": "markdown", "id": "1231aa1d", "metadata": { "papermill": { "duration": 0.000926, "end_time": "2026-10-02T14:41:09.497337+00:00", "exception": false, "start_time": "2026-10-02T14:41:09.496411+00:00", "status": "completed" }, "tags": [] }, "source": [ "# AddSubtractComp\n", "\n", "[AddSubtractComp](../../../_srcdocs/packages/components/add_subtract_comp) performs elementwise addition or subtraction between two or more compatible inputs. It may be vectorized to provide the result at one or more points simultaneously.\n", "\n", "$$\n", " result = a * \\textrm{scaling factor}_a + b * \\textrm{scaling factor}_b + c * \\textrm{scaling factor}_c + ...\n", "$$\n", "\n", "## AddSubtractComp Constructor\n", "\n", "The call signature for the `AddSubtractComp` constructor is:\n", "\n", "```{eval-rst}\n", " .. automethod:: openmdao.components.add_subtract_comp.AddSubtractComp.__init__\n", " :noindex:\n", "```\n", "\n", "## Using the AddSubtractComp\n", "\n", "The `add_equation` method is used to set up a system of inputs to be added/subtracted (with scaling factors).\n", "Each time the user adds an equation, all of the inputs and outputs must be of identical shape (this is a requirement for element-wise addition/subtraction).\n", "The units must also be compatible between all inputs and the output of each equation.\n", "\n", "## Method Signature\n", "\n", "```{eval-rst}\n", " .. automethod:: openmdao.components.add_subtract_comp.AddSubtractComp.add_equation\n", " :noindex:\n", "```\n", "\n", "## AddSubtractComp Example\n", "\n", "In the following example AddSubtractComp is used to add thrust, drag, lift, and weight forces. Note the scaling factor of -1 for the drag force and weight force." ] }, { "cell_type": "code", "execution_count": 2, "id": "2246e962", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:41:09.500365Z", "iopub.status.busy": "2026-10-02T14:41:09.500168Z", "iopub.status.idle": "2026-10-02T14:41:12.171240Z", "shell.execute_reply": "2026-10-02T14:41:12.170581Z" }, "papermill": { "duration": 2.673657, "end_time": "2026-10-02T14:41:12.171999+00:00", "exception": false, "start_time": "2026-10-02T14:41:09.498342+00:00", "status": "completed" }, "tags": [] }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "[1790952072.158905] [runnervm8df0l:6335 :0] ib_iface.c:1269 UCX ERROR mana_0: iface 0x55f0f24a10c0 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", "[1790952072.159198] [runnervm8df0l:6335 :0] ucp_worker.c:1412 UCX ERROR uct_iface_open(ud_verbs/mana_0:1) failed: Input/output error\n", "[[100. 0.]\n", " [200. -1.]\n", " [300. -2.]]\n" ] }, { "name": "stderr", "output_type": "stream", "text": [ "[runnervm8df0l:06335] pml_ucx.c:313 Error: Failed to create UCP worker\n" ] } ], "source": [ "import numpy as np\n", "import openmdao.api as om\n", "\n", "n = 3\n", "\n", "p = om.Problem()\n", "model = p.model\n", "\n", "# Construct an adder/subtracter here. create a relationship through the add_equation method\n", "adder = om.AddSubtractComp()\n", "adder.add_equation('total_force', input_names=['thrust', 'drag', 'lift', 'weight'],\n", " vec_size=n, length=2, scaling_factors=[1, -1, 1, -1], units='kN')\n", "# Note the scaling factors. we assume all forces are positive sign upstream\n", "\n", "# The vector represents forces at 3 time points (rows) in 2 dimensional plane (cols)\n", "p.model.add_subsystem(name='totalforcecomp', subsys=adder,\n", " promotes_inputs=['thrust', 'drag', 'lift', 'weight'])\n", "\n", "p.setup()\n", "\n", "# Set thrust to exceed drag, weight to equal lift for this scenario\n", "p['thrust'][:, 0] = [500, 600, 700]\n", "p['drag'][:, 0] = [400, 400, 400]\n", "p['weight'][:, 1] = [1000, 1001, 1002]\n", "p['lift'][:, 1] = [1000, 1000, 1000]\n", "\n", "p.run_model()\n", "\n", "# Verify the results\n", "expected_i = np.array([[100, 200, 300], [0, -1, -2]]).T\n", "print(p.get_val('totalforcecomp.total_force', units='kN'))" ] }, { "cell_type": "code", "execution_count": 3, "id": "fa26eea4", "metadata": { "execution": { "iopub.execute_input": "2026-10-02T14:41:12.174471Z", "iopub.status.busy": "2026-10-02T14:41:12.174236Z", "iopub.status.idle": "2026-10-02T14:41:12.179022Z", "shell.execute_reply": "2026-10-02T14:41:12.178400Z" }, "papermill": { "duration": 0.006465, "end_time": "2026-10-02T14:41:12.179421+00:00", "exception": false, "start_time": "2026-10-02T14:41:12.172956+00:00", "status": "completed" }, "tags": [ "remove-input", "remove-output" ] }, "outputs": [ { "data": { "text/plain": [ "np.float64(0.0)" ] }, "execution_count": 3, "metadata": {}, "output_type": "execute_result" } ], "source": [ "from openmdao.utils.assert_utils import assert_near_equal\n", "\n", "assert_near_equal(p.get_val('totalforcecomp.total_force', units='kN'), expected_i)" ] } ], "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": 3.813621, "end_time": "2026-10-02T14:41:12.695261+00:00", "environment_variables": {}, "exception": null, "input_path": "/home/runner/work/OpenMDAO/OpenMDAO/openmdao/docs/openmdao_book/features/building_blocks/components/add_subtract_comp.ipynb", "output_path": "/home/runner/work/OpenMDAO/OpenMDAO/openmdao/docs/_executed_book/features/building_blocks/components/add_subtract_comp.ipynb", "parameters": {}, "start_time": "2026-10-02T14:41:08.881640+00:00", "version": "2.7.0" } }, "nbformat": 4, "nbformat_minor": 5 }