NumericAxis.js revision 8209f3939e32e0e5bde64192267fdaf9db6f4fbc
/**
* NumericAxis manages numeric data on an axis.
*
* @param {Object} config (optional) Configuration parameters for the Chart.
* @class NumericAxis
* @constructor
* @extends AxisType
*/
function NumericAxis(config)
{
NumericAxis.superclass.constructor.apply(this, arguments);
}
NumericAxis.NAME = "numericAxis";
NumericAxis.ATTRS = {
/**
* Indicates whether 0 should always be displayed.
*
* @attribute alwaysShowZero
* @type Boolean
*/
alwaysShowZero: {
value: true
},
/**
* Method used for formatting a label. This attribute allows for the default label formatting method to overridden. The method use would need
* to implement the arguments below and return a `String`.
* <dl>
* <dt>val</dt><dd>Label to be formatted. (`String`)</dd>
* <dt>format</dt><dd>Object containing properties used to format the label. (optional)</dd>
* </dl>
*
* @attribute labelFunction
* @type Function
*/
labelFunction: {
value: function(val, format)
{
if(format)
{
return Y.DataType.Number.format(val, format);
}
return val;
}
},
/**
* Object containing properties used by the `labelFunction` to format a
* label.
*
* @attribute labelFormat
* @type Object
*/
labelFormat: {
value: {
prefix: "",
thousandsSeparator: "",
decimalSeparator: "",
decimalPlaces: "0",
suffix: ""
}
}
};
Y.extend(NumericAxis, Y.AxisType,
{
/**
* Type of data used in `Axis`.
*
* @property _type
* @readOnly
* @private
*/
_type: "numeric",
/**
* Returns a value based of a key value and an index.
*
* @method getKeyValueAt
* @param {String} key value used to look up the correct array
* @param {Number} index within the array
* @return Object
*/
getKeyValueAt: function(key, index)
{
var value = NaN,
keys = this.get("keys");
if(keys[key] && Y.Lang.isNumber(parseFloat(keys[key][index])))
{
value = keys[key][index];
}
return value;
},
/**
* Helper method for getting a `roundingUnit` when calculating the minimum and maximum values.
*
* @method _getMinimumUnit
* @param {Number} max Maximum number
* @param {Number} min Minimum number
* @param {Number} units Number of units on the axis
* @return Number
* @private
*/
_getMinimumUnit:function(max, min, units)
{
return this._getNiceNumber(Math.ceil((max - min)/units));
},
/**
* Calculates a nice rounding unit based on the range.
*
* @method _getNiceNumber
* @param {Number} roundingUnit The calculated rounding unit.
* @return Number
* @private
*/
_getNiceNumber: function(roundingUnit)
{
var tempMajorUnit = roundingUnit,
order = Math.ceil(Math.log(tempMajorUnit) * 0.4342944819032518),
roundedMajorUnit = Math.pow(10, order),
roundedDiff;
if (roundedMajorUnit / 2 >= tempMajorUnit)
{
roundedDiff = Math.floor((roundedMajorUnit / 2 - tempMajorUnit) / (Math.pow(10,order-1)/2));
tempMajorUnit = roundedMajorUnit/2 - roundedDiff*Math.pow(10,order-1)/2;
}
else
{
tempMajorUnit = roundedMajorUnit;
}
if(!isNaN(tempMajorUnit))
{
return tempMajorUnit;
}
return roundingUnit;
},
/**
* Calculates the maximum and minimum values for the `Axis`.
*
* @method _updateMinAndMax
* @private
*/
_updateMinAndMax: function()
{
var data = this.get("data"),
max = 0,
min = 0,
len,
num,
i,
key,
setMax = this.get("setMax"),
setMin = this.get("setMin");
if(!setMax && !setMin)
{
if(data && data.length && data.length > 0)
{
len = data.length;
max = min = data[0];
if(len > 1)
{
for(i = 1; i < len; i++)
{
num = data[i];
if(isNaN(num))
{
if(Y.Lang.isObject(num))
{
min = max = 0;
//hloc values
for(key in num)
{
if(num.hasOwnProperty(key))
{
max = Math.max(num[key], max);
min = Math.min(num[key], min);
}
}
}
max = setMax ? this._setMaximum : max;
min = setMin ? this._setMinimum : min;
continue;
}
max = setMax ? this._setMaximum : Math.max(num, max);
min = setMin ? this._setMinimum : Math.min(num, min);
}
}
}
this._roundMinAndMax(min, max);
}
},
/**
* Rounds the mimimum and maximum values based on the `roundingUnit` attribute.
*
* @method _roundMinAndMax
* @param {Number} min Minimum value
* @param {Number} max Maximum value
* @private
*/
_roundMinAndMax: function(min, max)
{
var roundingUnit,
minimumRange,
minGreaterThanZero = min >= 0,
maxGreaterThanZero = max > 0,
dataRangeGreater,
maxRound,
minRound,
topTicks,
botTicks,
tempMax,
tempMin,
units = this.getTotalMajorUnits() - 1,
alwaysShowZero = this.get("alwaysShowZero"),
roundingMethod = this.get("roundingMethod"),
useIntegers = (max - min)/units >= 1;
if(roundingMethod)
{
if(roundingMethod == "niceNumber")
{
roundingUnit = this._getMinimumUnit(max, min, units);
if(minGreaterThanZero && maxGreaterThanZero)
{
if(alwaysShowZero || min < roundingUnit)
{
min = 0;
}
roundingUnit = this._getMinimumUnit(max, min, units);
max = this._roundUpToNearest(max, roundingUnit);
}
else if(maxGreaterThanZero && !minGreaterThanZero)
{
topTicks = Math.round( units / ((-1 * min)/max + 1) );
topTicks = Math.max(Math.min(topTicks, units - 1), 1);
botTicks = units - topTicks;
tempMax = Math.ceil( max/topTicks );
tempMin = Math.floor( min/botTicks ) * -1;
roundingUnit = Math.max(tempMax, tempMin);
roundingUnit = this._getNiceNumber(roundingUnit);
max = roundingUnit * topTicks;
min = roundingUnit * botTicks * -1;
}
else
{
if(alwaysShowZero || max === 0 || max + roundingUnit > 0)
{
max = 0;
roundingUnit = this._getMinimumUnit(max, min, units);
}
else
{
max = this._roundUpToNearest(max, roundingUnit);
}
min = max - (roundingUnit * units);
}
}
else if(roundingMethod == "auto")
{
if(minGreaterThanZero && maxGreaterThanZero)
{
if(alwaysShowZero || min < (max-min)/units)
{
min = 0;
}
roundingUnit = (max - min)/units;
if(useIntegers)
{
roundingUnit = Math.ceil(roundingUnit);
}
max = min + (roundingUnit * units);
}
else if(maxGreaterThanZero && !minGreaterThanZero)
{
if(alwaysShowZero)
{
topTicks = Math.round( units / ( (-1 * min) /max + 1) );
topTicks = Math.max(Math.min(topTicks, units - 1), 1);
botTicks = units - topTicks;
if(useIntegers)
{
tempMax = Math.ceil( max/topTicks );
tempMin = Math.floor( min/botTicks ) * -1;
}
else
{
tempMax = max/topTicks;
tempMin = min/botTicks * -1;
}
roundingUnit = Math.max(tempMax, tempMin);
max = roundingUnit * topTicks;
min = roundingUnit * botTicks * -1;
}
else
{
roundingUnit = (max - min)/units;
if(useIntegers)
{
roundingUnit = Math.ceil(roundingUnit);
}
min = this._roundDownToNearest(min, roundingUnit);
max = this._roundUpToNearest(max, roundingUnit);
}
}
else
{
roundingUnit = (max - min)/units;
if(useIntegers)
{
roundingUnit = Math.ceil(roundingUnit);
}
if(alwaysShowZero || max === 0 || max + roundingUnit > 0)
{
max = 0;
roundingUnit = (max - min)/units;
if(useIntegers)
{
Math.ceil(roundingUnit);
}
}
else
{
max = this._roundUpToNearest(max, roundingUnit);
}
min = max - (roundingUnit * units);
}
}
else if(!isNaN(roundingMethod) && isFinite(roundingMethod))
{
roundingUnit = roundingMethod;
minimumRange = roundingUnit * units;
dataRangeGreater = (max - min) > minimumRange;
minRound = this._roundDownToNearest(min, roundingUnit);
maxRound = this._roundUpToNearest(max, roundingUnit);
if(minGreaterThanZero && maxGreaterThanZero)
{
if(alwaysShowZero || minRound <= 0)
{
min = 0;
}
else
{
min = minRound;
}
if(!dataRangeGreater)
{
max = min + minimumRange;
}
else
{
max = maxRound;
}
}
else if(maxGreaterThanZero && !minGreaterThanZero)
{
min = minRound;
if(!dataRangeGreater)
{
max = min + minimumRange;
}
else
{
max = maxRound;
}
}
else
{
if(max === 0 || alwaysShowZero)
{
max = 0;
}
else
{
max = maxRound;
}
if(!dataRangeGreater)
{
min = max - minimumRange;
}
else
{
min = minRound;
}
}
}
}
this._dataMaximum = max;
this._dataMinimum = min;
},
/**
* Calculates and returns a value based on the number of labels and the index of
* the current label.
*
* @method getLabelByIndex
* @param {Number} i Index of the label.
* @param {Number} l Total number of labels.
* @return String
*/
getLabelByIndex: function(i, l)
{
var min = this.get("minimum"),
max = this.get("maximum"),
increm = (max - min)/(l-1),
label;
l -= 1;
label = min + (i * increm);
if(i > 0)
{
label = this._roundToNearest(label, increm);
}
return label;
},
/**
* Rounds a Number to the nearest multiple of an input. For example, by rounding
* 16 to the nearest 10, you will receive 20. Similar to the built-in function Math.round().
*
* @method _roundToNearest
* @param {Number} number Number to round
* @param {Number} nearest Multiple to round towards.
* @return Number
* @private
*/
_roundToNearest: function(number, nearest)
{
nearest = nearest || 1;
if(nearest === 0)
{
return number;
}
var roundedNumber = Math.round(this._roundToPrecision(number / nearest, 10)) * nearest;
return this._roundToPrecision(roundedNumber, 10);
},
/**
* Rounds a Number up to the nearest multiple of an input. For example, by rounding
* 16 up to the nearest 10, you will receive 20. Similar to the built-in function Math.ceil().
*
* @method _roundUpToNearest
* @param {Number} number Number to round
* @param {Number} nearest Multiple to round towards.
* @return Number
* @private
*/
_roundUpToNearest: function(number, nearest)
{
nearest = nearest || 1;
if(nearest === 0)
{
return number;
}
return Math.ceil(this._roundToPrecision(number / nearest, 10)) * nearest;
},
/**
* Rounds a Number down to the nearest multiple of an input. For example, by rounding
* 16 down to the nearest 10, you will receive 10. Similar to the built-in function Math.floor().
*
* @method _roundDownToNearest
* @param {Number} number Number to round
* @param {Number} nearest Multiple to round towards.
* @return Number
* @private
*/
_roundDownToNearest: function(number, nearest)
{
nearest = nearest || 1;
if(nearest === 0)
{
return number;
}
return Math.floor(this._roundToPrecision(number / nearest, 10)) * nearest;
},
/**
* Rounds a number to a certain level of precision. Useful for limiting the number of
* decimal places on a fractional number.
*
* @method _roundToPrecision
* @param {Number} number Number to round
* @param {Number} precision Multiple to round towards.
* @return Number
* @private
*/
_roundToPrecision: function(number, precision)
{
precision = precision || 0;
var decimalPlaces = Math.pow(10, precision);
return Math.round(decimalPlaces * number) / decimalPlaces;
}
});
Y.NumericAxis = NumericAxis;