package joptima.functions;

/**
 * A function that can make parameters stick to given values.
 */
public abstract class ConstrainableFunction implements joptima.Function {
  /**
   * Removes the given parameter from the parameter list.
   * This constraint is mandatory to implement.
   */
  public abstract void constrain(String parametername);

  /**
   * Remembers a value and error bar to constrain the given parameter to.
   * The actual constraining must happen in the {@link Fitter}, since it
   * depends on the particular likelihood function in use.
   */
  public void constrain(String parametername, double value, double error) {
    throw new UnsupportedOperationException();
  }

  /**
   * Remembers a value and error bars to constrain the given parameter to.
   * The actual constraining must happen in the {@link Fitter}, since it
   * depends on the particular likelihood function in use.
   */
  public void constrain(String parametername, double value, double pluserror, double minuserror) {
    throw new UnsupportedOperationException();
  }

  /**
   * Flags indicating which parameters are constrained.
   */
  protected boolean[] m_constrained;

  /**
   * Convenience function calculating the number of unconstrained parameters.
   */
  protected int countUnconstrained() {
    int num = 0;
    for (int i = 0; i < m_constrained.length; i++) {
      if (!m_constrained[i]) num++;
    }
    return num;
  }
}