net.quies.math.plot
Class LinearDecimalIndexScheme

java.lang.Object
  net.quies.math.plot.IndexScheme
      net.quies.math.plot.LinearIndexScheme
          net.quies.math.plot.LinearDecimalIndexScheme

public final class LinearDecimalIndexScheme
extends LinearIndexScheme

Makes stepsizes of 1, 2, 4 or 5 times a power of 10.

Since:

1.0

Author:

Pascal S. de Kloe

Constructor Summary

LinearDecimalIndexScheme()

Method Summary

protected BigDecimal

getStepsize(BigDecimal preferredStepsize) Gets a suitable stepsize which will produce a number of steps as close as possible tho the ideal with preferredStepsize.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LinearDecimalIndexScheme

public LinearDecimalIndexScheme()

Since:

1.0

Method Detail

getStepsize

protected BigDecimal getStepsize(BigDecimal preferredStepsize)

Description copied from class: LinearIndexScheme

Gets a suitable stepsize which will produce a number of steps as close as possible tho the ideal with preferredStepsize. The therm suitable is defined by the subclass of this class. If preferredStepsize is not a suitable stepsize this method must decide wheather to use a smaller or a larger one with the following algorithm.

Let a be the largest suitable stepsize less than preferredStepsize and let b be the smallest suitable stepsize greather than preferredStepsize.
Let r be the range of the dimension which is the diference between the highest and the lowest value.

The break point x lies where a is equally wrong than b so x is where the number of steps to many with a is equal to the number of steps short with b.

 r/a - r/x = r/x - r/b
 1/a + 1/b = 1/x + 1/x
 b/ab + a/ab = 2/x
 2/x = (a+b)/ab
 x = 2ab/(a+b)
 

For example the break point between stepsize 1 and stepsize 2 is 4/3.

Specified by:

getStepsize in class LinearIndexScheme

Since:

1.0