Re: Using visad logarithm


Brobbey,Isaac (neuron) wrote:
hi all:
i have a display of spikes which are all clustered to some area in the
display box and i want to use the
log scale to spread it out. so it can cover most part of the grid. now the
useage is what i might need a little help with, like this is what i have: i have a math type like: (mass,pi)->ratio RealType mass = RealType.getRealType("mass"); RealType pi = RealType.getRealType("pi"); RealType ratio = RealType.getRealType("ratio"); RealTupleType cartesian = new RealTupleType(mass, pi); FunctionType Ftype = new FunctionType(cartesian, ratio); i want my x-axis to be mass and y-axis to be pi and z-axis to be ratio. i dont want to take the log on the z-axis(ratio). i am not sure if the above function type is the same as FunctionType Ftype = new FunctionType((mass,pi), ratio); at what point should i take the logs on the mass and pi ? and how will it fit with the data reference and the display object.

i will be glad if you can show me some code snippets. thanks in advance:

I'm not sure if this will work, but try something like:

   RealType logMass = RealType.getRealType("logMass");
   RealType logPi = RealType.getRealType("logPi");
   RealTupleType logType = new RealTupleType(logMass, logPi);
   CoordinateSystem refCS = new LogCoordinateSystem(ref);
   RealTupleType cartesian = new RealTupleType(mass, pi, refCS, null);

Then map whichever log RealType you want to show as logs to
whichever axis it belongs on.

Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307