differentialequation.java

来自「一个一元曲线多项式数值演示例子」· Java 代码 · 共 62 行

package numbercruncher.mathutils;

/**
 * The base class for functions that can have derivatives.
 * Initialize the static function table with some sample functions.
 */
public abstract class DifferentialEquation
    implements Evaluatable {
  /** initial condition */
  private DataPoint initialCondition;
  /** solution function label */
  private String solutionLabel;

  /**
   * Constructor.
   * @param initialCondition the initial condition data point
   * @param solutionLabel the solution function label
   */
  public DifferentialEquation(DataPoint initialCondition,
                              String solutionLabel) {
    this.initialCondition = initialCondition;
    this.solutionLabel = solutionLabel;
  }

  /**
   * Return the initial condition data point.
   * @return the initial condition
   */
  public DataPoint getInitialCondition() {
    return initialCondition;
  }

  /**
   * Return the solution label.
   * @return the label
   */
  public String getSolutionLabel() {
    return solutionLabel;
  }

  /**
   * Return the value of the differential equation at x.
   * (Implementation of Evaluatable.)
   * @param x the value of x
   * @return the solution value
   */
  public abstract float at(float x);

  /**
   * Return the value of the differential equation at (x, y).
   * @return the solution value
   */
  public float at(float x, float y) {
    return at(x);
  }

  /**
   * Return the value of the solution at x.
   * @return the solution value
   */
  public abstract float solutionAt(float x);
}