NChartBrushScale Class Reference
| Inherits from | NSObject |
|---|---|
| Declared in | NChartBrushScale.h |
Overview
The NChartBrushScale class provides scale that transforms values into brushes like a step mapping function.
The scale contains array of reference values and array of brushes. It returns brush for given value
according to these arrays:
brushes[n]
values[n - 1]
...
brushes[4]
values[3]
brushes[3]
values[2]
brushes[2]
values[1]
brushes[1]
values[0]
brushes[0]
This is equivalent to the following pseudo code:
if value <= values[0] return brushes[0];
if value > values[i] and value <= values[i + 1] return brush[i + 1];
if value > values[last] return brush[last]
So the array of brushes should contain n elements and array of values should contain n - 1. Values should be sorted (NChartBrushScale does not sort them automatically). If they are not, it can lead to strange results. If brush index goes out of range, nil is returned.
+ brushScaleWithBrushes:andValues:
Create new instance of NChartBrushScale with arrays of brushes and values.
+ (NChartBrushScale *)brushScaleWithBrushes:(NSArray *)brushes andValues:(NSArray *)valuesParameters
brushes |
|
|---|---|
values |
|
Return Value
a new instance of NChartBrushScale.
Declared In
NChartBrushScale.h
+ linearBrushScaleWithBrushes:minValue:maxValue:
Create new instance of NChartBrushScale with linear space of values.
+ (NChartBrushScale *)linearBrushScaleWithBrushes:(NSArray *)brushes minValue:(double)minValue maxValue:(double)maxValueParameters
brushes |
|
|---|---|
minValue |
|
maxValue |
|
Return Value
a new instance of NChartBrushScale.
Declared In
NChartBrushScale.h
+ logarithmicBrushScaleWithBrushes:minValue:maxValue:logarithmBase:
Create new instance of NChartBrushScale with logarithmic space of values.
+ (NChartBrushScale *)logarithmicBrushScaleWithBrushes:(NSArray *)brushes minValue:(double)minValue maxValue:(double)maxValue logarithmBase:(double)logarithmBaseParameters
brushes |
|
|---|---|
minValue |
|
maxValue |
|
logarithmBase |
|
Return Value
a new instance of NChartBrushScale.
Declared In
NChartBrushScale.h
– initWithBrushes:andValues:
Init new instance of NChartBrushScale with arrays of brushes and values.
- (id)initWithBrushes:(NSArray *)brushes andValues:(NSArray *)valuesParameters
brushes |
|
|---|---|
values |
|
Return Value
initialized instance of NChartBrushScale.
Declared In
NChartBrushScale.h
– initLinearWithBrushes:minValue:maxValue:
Init new instance of NChartBrushScale with linear space of values.
- (id)initLinearWithBrushes:(NSArray *)brushes minValue:(double)minValue maxValue:(double)maxValueParameters
brushes |
|
|---|---|
minValue |
|
maxValue |
|
Return Value
a new instance of NChartBrushScale.
Declared In
NChartBrushScale.h
– initLogarithmicWithBrushes:minValue:maxValue:logarithmBase:
Init new instance of NChartBrushScale with logarithmic space of values.
- (id)initLogarithmicWithBrushes:(NSArray *)brushes minValue:(double)minValue maxValue:(double)maxValue logarithmBase:(double)logarithmBaseParameters
brushes |
|
|---|---|
minValue |
|
maxValue |
|
logarithmBase |
|
Return Value
a new instance of NChartBrushScale.
Declared In
NChartBrushScale.h
brushes
Array of brushes.
@property (nonatomic, readonly) NSArray *brushesDeclared In
NChartBrushScale.h
values
Array of values.
@property (nonatomic, readonly) NSArray *valuesDeclared In
NChartBrushScale.h
isGradient
Flag determining if scale can return gradient colors. The default value is YES.
The gradient scale assumes that the array of brushes contains instances of NChartSolidColorBrush and
linearly interpolates colors that correspond to the neighbor values.
@property (nonatomic, assign) BOOL isGradientDeclared In
NChartBrushScale.h
isLogarithmic
Flag determining if the scale is linear (NO) or logarithmic (YES). The default value is NO.
@property (nonatomic, assign) BOOL isLogarithmicDeclared In
NChartBrushScale.h
logarithmBase
Logarithm base. Takes effect if isLogarithmic is YES only. The default value is 10.
@property (nonatomic, assign) double logarithmBaseDeclared In
NChartBrushScale.h
isStrict
Strict brush range flag. The default value is NO. Strict brush range (YES in this property) means, that if value is less than value[0] or bigger than value[n - 1], clear (transparent) brush is returned. Otherwhise (NO in this property), brushes[0] and brushes[n] respectively is returned.
@property (nonatomic, assign) BOOL isStrictDeclared In
NChartBrushScale.h
– brushForValue:
Get value for brush.
- (NChartBrush *)brushForValue:(NSNumber *)valueParameters
value |
|
|---|
Return Value
brush for given value.
Declared In
NChartBrushScale.h