Base template class for all Parametric Functions. The template argument is the type of parameteric function interface is implementing like Parameteric 1D, Multi-Dim or gradient parametric. A parameteric function is a Generic Function with parameters, so it is a function object which carries a state, the parameters. The parameters are described with a standard vector of doubles. This class contains the default implementations for the methods defined in the IParamFunction interface for dealing with parameters Specific parameteric function classes should derive from this class if they want to profit from default implementations for the abstract methods. The derived classes need to implement only the DoEvalPar( x, p) and Clone() methods for non-gradient parameteric functions or DoParameterDerivative(x,p,ipar) for gradient par functions @ingroup ParamFunc
copying constructors (can use default ones) Access the parameter values
{ return &fParams.front(); }
Set the parameter values @param p vector of doubles containing the parameter values.