cern.extjfx.chart.data

Class LinearDataReducer<X extends Number,Y extends Number>

java.lang.Object

cern.extjfx.chart.data.LinearDataReducer<X,Y>

All Implemented Interfaces:

DataReducer<Number,Number>

public class LinearDataReducer<X extends Number,Y extends Number>
extends Object
implements DataReducer<Number,Number>

Implementation of the DataReducer that reduces a large data set to the number of visible pixels

• The algorithm goes through the data along the X axis from xMin to xMax. It typically merges the value of several original points into two pixel value, by picking the minimum and maximum Y value from the original data.
• The original data can have "holes", i.e. no data points between two X values. In this case, the algorithm interpolates data in between.
• If the size of the data set is smaller than the number of pixels, it is not reduced. The resulting "reduced" data therefore contains the same number of points as the original, which may be fewer than the pixels.

Author:

Stephane Bart Pedersen, Vito Baggiolini

Constructor Summary

Constructors

Constructor and Description
LinearDataReducer()

Method Summary

Modifier and Type	Method and Description
List<XYChart.Data<Number,Number>>	reduce(ChartData<Number,Number> data, Range<Double> dataRange, int maxPointsCount) Reduces the number of data points to be equal or less than specified maxPointsCount.
List<XYChart.Data<Number,Number>>	reduce(double[] xIn, double[] yIn, double xMin, double xMax, int width_scene) Algorithm that actually does the work.

Methods inherited from class java.lang.Object

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

Constructor Detail

LinearDataReducer

public LinearDataReducer()

Method Detail

reduce

public List<XYChart.Data<Number,Number>> reduce(ChartData<Number,Number> data,
                                                Range<Double> dataRange,
                                                int maxPointsCount)

Description copied from interface: DataReducer

Reduces the number of data points to be equal or less than specified maxPointsCount.

Specified by:

reduce in interface DataReducer<Number,Number>

Parameters:

data - data to be reduced

dataRange - range of data (lowerBound and upperBound) from which given data should be reduced

maxPointsCount - the maximum number of points that the reduced list should contain

Returns:

list containing reduced data, with maximum maxPointsCount elements

reduce

public List<XYChart.Data<Number,Number>> reduce(double[] xIn,
                                                double[] yIn,
                                                double xMin,
                                                double xMax,
                                                int width_scene)

Algorithm that actually does the work.

Parameters:

xIn - x-axis input data (original), must have the same length as yIn

yIn - y-axis input data (original), must have the same length as xIn

xMin - lower bound of data to be reduced, given in original x units. By default this is the first value of xIn, i.e. xIn[0]

xMax - upper bound of data to be reduced, given in original x units. By default this is last value of xIn, i.e. xIn[xIn.length-1]

width_scene - in pixels = number of points the reduced data shall have

Returns:

list containing reduced data, with maximum width_scene elements