com.ab.view.chart.MathHelper类 参考

静态 Public 成员函数
static double[]	minmax (List< Double > values)
static List< Double >	getLabels (final double start, final double end, final int approxNumLabels)
static float[]	getFloats (List< Float > values)
static double[]	getDoubles (List< Double > values)
static int[]	getInts (List< Integer > values)

静态 Public 属性
static final double	NULL_VALUE = Double.MAX_VALUE

Private 成员函数
	MathHelper ()

静态 Private 成员函数
static double[]	computeLabels (final double start, final double end, final int approxNumLabels)
static double	roundUp (final double val)

静态 Private 属性
static final NumberFormat	FORMAT = NumberFormat.getNumberInstance()

详细描述

Utility class for math operations.

构造及析构函数说明

com.ab.view.chart.MathHelper.MathHelper ( )

inlineprivate

Instantiates a new math helper.

成员函数说明

static double [] com.ab.view.chart.MathHelper.computeLabels ( final double  start, final double  end, final int  approxNumLabels  )

inlinestaticprivate

Computes a reasonable number of labels for a data range.

参数

start	start value
end	final value
approxNumLabels	desired number of labels

返回

double[] array containing {start value, end value, increment}

static double [] com.ab.view.chart.MathHelper.getDoubles ( List< Double >  values )

inlinestatic

Transforms a list of Double values into an array of double.

参数

values

the list of Double

返回

the array of doubles

static float [] com.ab.view.chart.MathHelper.getFloats ( List< Float >  values )

inlinestatic

Transforms a list of Float values into an array of float.

参数

values

the list of Float

返回

the array of floats

static int [] com.ab.view.chart.MathHelper.getInts ( List< Integer >  values )

inlinestatic

Gets the ints.

参数

values

the values

返回

the ints

static List<Double> com.ab.view.chart.MathHelper.getLabels ( final double  start, final double  end, final int  approxNumLabels  )

inlinestatic

Computes a reasonable set of labels for a data interval and number of labels.

参数

start	start value
end	final value
approxNumLabels	desired number of labels

返回

collection containing {start value, end value, increment}

static double [] com.ab.view.chart.MathHelper.minmax ( List< Double >  values )

inlinestatic

Calculate the minimum and maximum values out of a list of doubles.

参数

values

the input values

返回

an array with the minimum and maximum values

static double com.ab.view.chart.MathHelper.roundUp ( final double  val )

inlinestaticprivate

Given a number, round up to the nearest power of ten times 1, 2, or 5. The argument must be strictly positive.

参数

val

the val

返回

the double

类成员变量说明

final NumberFormat com.ab.view.chart.MathHelper.FORMAT = NumberFormat.getNumberInstance()

staticprivate

A number formatter to be used to make sure we have a maximum number of fraction digits in the labels.

final double com.ab.view.chart.MathHelper.NULL_VALUE = Double.MAX_VALUE

static

A value that is used a null value.

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该类的文档由以下文件生成:

• src/com/ab/view/chart/MathHelper.java