#ifndef INVERSE_LINK_FUNC_H_
#define INVERSE_LINK_FUNC_H_

#include <string>
#include <functions/ScalarFunc.h>

/**
 * @short Base class for inverse link function 
 *
 * Link functions may be expressed in the BUGS language using an
 * S-style replacement function notation. For example the log link may
 * be expressed as log(y) <- a + b*x or as y <- exp(a + b*x).
 * In this case, the name of the inverse link function is "exp"
 * and its link name is "log".
 */
class InverseLinkFunc : public ScalarFunc
{
  const std::string _link;
public:
  InverseLinkFunc (std::string const &name, std::string const &link);
  /**
   * Returns the name of the link function
   */
  std::string const &linkName () const;
  /** Link function */
  virtual double link(double mu) const = 0;
  /** Gradient of link function */
  virtual double gradLink(double mu) const = 0;
};

#endif