Refactor solver configuration in FEAScript; remove coefficient functions handling and update boundary conditions application

Author: nikoscham

README.md

@@ -6,7 +6,7 @@
 
 <!-- [![liberapay](https://img.shields.io/liberapay/receives/FEAScript.svg?logo=liberapay)](https://liberapay.com/FEAScript/) -->
 
-[FEAScript](https://feascript.com/) is a lightweight finite element simulation library written in JavaScript. It empowers users to create and execute simulations for physics and engineering applications in both browser-based and server-side environments. This is the core library of the FEAScript project.
+[FEAScript](https://feascript.com/) is a lightweight finite element simulation library written in JavaScript. It empowers users to perform simulations for physics and engineering applications in both browser-based and server-side environments. This is the core library of the FEAScript project.
 
 > 🚧 **FEAScript is currently under heavy development.** Its functionality and interfaces may change rapidly as new features and enhancements are introduced.
 

src/FEAScript.js

@@ -34,20 +34,12 @@ export class FEAScriptModel {
   }
 
   /**
-   * Sets the solver configuration and optionally PDE coefficient functions
+   * Sets the solver configuration
    * @param {string} solverConfig - Parameter specifying the type of solver
-   * @param {object} [options] - Additional solver options
-   * @param {object} [options.coefficientFunctions] - Functions A(x), B(x), C(x), D(x) for general form PDE
    */
-  setSolverConfig(solverConfig, options = {}) {
+  setSolverConfig(solverConfig = {}) {
     this.solverConfig = solverConfig;
 
-    // Store coefficient functions if provided
-    if (options.coefficientFunctions) {
-      this.coefficientFunctions = options.coefficientFunctions;
-      debugLog(`Coefficient functions set for ${solverConfig}`);
-    }
-
     debugLog(`Solver config set to: ${solverConfig}`);
   }
 
@@ -158,29 +150,16 @@ export class FEAScriptModel {
     } else if (this.solverConfig === "generalFormPDEScript") {
       basicLog(`Using solver: ${this.solverConfig}`);
 
-      // Check if coefficient functions are provided
-      if (!this.coefficientFunctions) {
-        const error = "Coefficient functions must be provided for general form PDE solver";
-        errorLog(error);
-        throw new Error(error);
-      }
-
       if (this.solverMethod === "frontal") {
         // For frontal solver
-        const frontalResult = runFrontalSolver(
-          assembleGeneralFormPDEFront,
-          meshData,
-          this.boundaryConditions,
-          { coefficientFunctions: this.coefficientFunctions }
-        );
-        solutionVector = frontalResult.solutionVector;
       } else {
         // For other solver methods
-        ({ jacobianMatrix, residualVector } = assembleGeneralFormPDEMat(
-          meshData,
-          this.boundaryConditions,
-          this.coefficientFunctions
-        ));
+        ({ jacobianMatrix, residualVector } = assembleGeneralFormPDEMat(meshData, this.boundaryConditions, {
+          A: () => 1, // Diffusion coefficient
+          B: () => 1, // Advection coefficient
+          C: () => 0, // Reaction coefficient
+          D: () => 0, // Source term
+        }));
         const linearSystemResult = solveLinearSystem(this.solverMethod, jacobianMatrix, residualVector);
         solutionVector = linearSystemResult.solutionVector;
       }

src/solvers/generalFormPDEScript.js

@@ -13,73 +13,6 @@ import { initializeFEA, performIsoparametricMapping1D } from "../mesh/meshUtilsS
 import { GenericBoundaryConditions } from "./genericBoundaryConditionsScript.js";
 import { basicLog, debugLog, errorLog } from "../utilities/loggingScript.js";
 
-/**
- * Class to handle general form PDE boundary conditions application
- * Extends GenericBoundaryConditions for PDE-specific conditions
- */
-export class GeneralFormPDEBoundaryConditions extends GenericBoundaryConditions {
-  /**
-   * Constructor to initialize the GeneralFormPDEBoundaryConditions class
-   * @param {object} boundaryConditions - Object containing boundary conditions for the finite element analysis
-   * @param {array} boundaryElements - Array containing elements that belong to each boundary
-   * @param {array} nop - Nodal numbering (NOP) array representing the connectivity between elements and nodes
-   * @param {string} meshDimension - The dimension of the mesh (e.g., "1D")
-   * @param {string} elementOrder - The order of elements (e.g., "linear")
-   * @param {object} coefficients - Coefficient functions for the PDE
-   */
-  constructor(boundaryConditions, boundaryElements, nop, meshDimension, elementOrder, coefficients) {
-    super(boundaryConditions, boundaryElements, nop, meshDimension, elementOrder);
-    this.coefficients = coefficients;
-  }
-
-  /**
-   * Function to impose Dirichlet boundary conditions for the general form PDE
-   * @param {array} residualVector - The residual vector to be modified
-   * @param {array} jacobianMatrix - The Jacobian matrix to be modified
-   */
-  imposeDirichletBoundaryConditions(residualVector, jacobianMatrix) {
-    for (const [boundaryKey, condition] of Object.entries(this.boundaryConditions)) {
-      if (condition[0] === "constantValue") {
-        const value = condition[1];
-        const boundaryNodes = this.getBoundaryNodes(boundaryKey);
-
-        for (const nodeIndex of boundaryNodes) {
-          // Standard Dirichlet implementation
-          for (let i = 0; i < jacobianMatrix.length; i++) {
-            jacobianMatrix[nodeIndex][i] = 0;
-          }
-          jacobianMatrix[nodeIndex][nodeIndex] = 1;
-          residualVector[nodeIndex] = value;
-        }
-      }
-    }
-    debugLog("Dirichlet boundary conditions applied for general form PDE");
-  }
-
-  /**
-   * Get all nodes associated with a boundary
-   * @param {string} boundaryKey - The key identifying the boundary
-   * @returns {array} Array of node indices
-   */
-  getBoundaryNodes(boundaryKey) {
-    const boundaryNodes = new Set();
-    const elements = this.boundaryElements[boundaryKey];
-
-    if (!elements) {
-      errorLog(`Boundary ${boundaryKey} not found`);
-      return [];
-    }
-
-    for (const element of elements) {
-      for (const node of this.nop[element]) {
-        boundaryNodes.add(Math.abs(node) - 1); // Convert to 0-based indexing
-      }
-    }
-
-    return Array.from(boundaryNodes);
-  }
-}
-
 /**
  * Function to assemble the Jacobian matrix and residuals vector for the general form PDE model
  * @param {object} meshData - Object containing prepared mesh data
@@ -200,17 +133,16 @@ export function assembleGeneralFormPDEMat(meshData, boundaryConditions, coeffici
   }
 
   // Apply boundary conditions
-  const pdeBoundaryConditions = new GeneralFormPDEBoundaryConditions(
+  const genericBoundaryConditions = new GenericBoundaryConditions(
     boundaryConditions,
     boundaryElements,
     nop,
     meshDimension,
-    elementOrder,
-    coefficientFunctions
+    elementOrder
   );
 
   // Apply Dirichlet boundary conditions only
-  pdeBoundaryConditions.imposeDirichletBoundaryConditions(residualVector, jacobianMatrix);
+  genericBoundaryConditions.imposeDirichletBoundaryConditions(residualVector, jacobianMatrix);
 
   basicLog("General form PDE matrix assembly completed");