Trace

 

For efficiency reasons the timedependent behaviour of a point is not collected in a huge list of timesteps with points as pre_object or post_object but in one data structure containing the position of the points (x,y,z)(t) and the corresponding times t in arrays. We name the corresponding class Trace. The structure Trace for an instance of this class look as follows
 

#CLASS Trace : Triang1d {
  double *t;
};

   

GRAPE(trace, "display")()

TRACE *trace

In the grid mode of the graphic device the curve is drawn as a line. In the patch mode this line is rendered as a pipe with a leading arrow at the top and a completing half ball at the tail. The parameters are included in the option menu of the manager as rulers. For further details we refer to the documentation of the same method on the class Triang1d.

           

(TRACE *)GRAPE(trace, "read")()

(TRACE *)GRAPE(Trace, "read")()

(TRACE *)GRAPE(trace, "xdr")(xdrp)

TRACE *trace
CLASS *Trace
XDR *xdrp;

A Trace instance is read from the standard textdevice. If "read" fails it returns NULL. This method only exists for backward compatibility to read files written with "write" and is replaced by the GRAPE-xdr device. To get more information about XDR the eXtended Data Representaion see 5.7.

   

GRAPE(trace, "shorting")(eps)

TRACE *trace
double eps

This method modifies the points in a Trace instance by throwing away points which distance to their neighbours are smaller then eps. The resulting Trace instance has therefore a minimum distance between two neighbour points of eps size.