HODOGRAPH is the jGraph module of jLab.

 HODOGRAPH   Generate hodograph plots (simple and fancy).
 
    A hodograph of a velocity time series is defined as a polar
    coordinate plot of the eastward component versus the northward.
   
    Simple hodographs:
 
      HODOGRAPH(U,V) generates a simple hodograph plotting U versus V.
      U and V are column vectors, or matrices with time oriented in
      columns.  
   
      HODOGRAPH(CV), where CV=U+iV, also works.
 
    Fancy hodographs:
 
      A fancy hodograph use SCATTER to plot change the color and/or
      sizes of the points according to another parameter, say density.
      A colorbar is also plotted.
 
      HODOGRAPH(U,V,C) uses C as the symbol color.  The array C must
      have the same size as U and V.
 
      HODOGRAPH(U,V,C,S) also uses S as the symbol size.  The array S
      must have the same size as U and V.
 	
      HODOGRAPH(CV,C) and HODOGRAPH(CV,C,S) also work.
 
      Note that since SCATTER is slow for large datasets, it is useful
      to decimate the data before plotting.  This is accomplished
      using HODOGRAPH(...,INDEX). Then only the points CV(INDEX,:) are
      plotted.
 
      [H,HC]=FHODOGRAPH(...) returns the handle H to the data, and the
      handle HC to the colorbar axis.
 
    As an example,
   
           load bravo94
           cv=vfilt(bravo94.rcm.cv(:,3),24);
           th=100*detrend(bravo94.cat.th(:,3));
           [h,hc]=hodograph(cv,th,20+0*th,[1:4000]);
           caxis([-8 8])
          
    makes Figure 6a of Lilly and Rhines (2002) JPO.
          
    Usage: hodograph(cv);
           [h,hc]=hodograph(cv,c,index);
           [h,hc]=hodograph(cv,c,s,index);
    _________________________________________________________________
    This is part of JLAB --- type 'help jlab' for more information 
    (C) 2000--2016 J.M. Lilly --- type 'help jlab_license' for details