void Plot4dPnt (x, y, z, v, vmax, sym) D4PLT.C Level 2
float x, y, z The coordinates of the volume value.
float v The volume value to be plotted at the x, y, z point.
float vmax The maximum volume value to be expected. A point plotted with this value of volume will result in a rectangular volume that is 1/10 the size of each axis. This should be the same for each call to Plot4dPnt(). If you wish to start a second 4-D plot, you should call Plot4dPnt() with vmax = 0.0f to renormalize the internal scaling factors.
int sym The symbol to be plotted in the center of each volume. If sym == -1, the symbol is suppressed.
Plot4DPnt() plots a single value (as a volume) at the specified position. The symbol, volume, and projection are plotted with the presently active color. You may wish to select the active color according to the value of the volume using the function zvalueq() in SVC.C. An example of this is given in the code for PlumePlotN().