我想编写一个自动滚动的绘图，所以实际时间在右侧。（标记为红色）
以时间间隔不规则地添加数据。我怎样才能做到这一点？我已经有一个滚动图（基于 coreplot 提供的示例代码）。但它并不完全准确并且非常消耗CPU。标签也应该是“圆形”时间，例如 14:52:00 14:52:20 等等。
到目前为止，这是我的代码：
测试窗口控制器.h
@interface TestWindowController : NSWindowController<CPTPlotDataSource> {
NSMutableArray *plotData;
double currentIndex;
NSDate *referenceDate;
NSTimer *scrollTimer;
NSTimer *newDataTimer;
}
@property (weak) IBOutlet CPTGraphHostingView *graphView;
测试窗口控制器.m
NSString *kPlotIdentifier = @"Data Source Plot";
const double kTimePeriod = 60.0; // 1 Minute
const double kFrameRate = 10.0; // frames per second
const double kAlpha = 0.25; // smoothing constant
@interface DataObj : NSObject {
NSTimeInterval timeInterval;
double testValue;
}
@property(readwrite) NSTimeInterval timeInterval;
@property(readwrite) double testValue;
@end
@implementation DataObj
@synthesize timeInterval;
@synthesize testValue;
@end
@implementation TestWindowController
@synthesize graphView;
- (id)initWithWindow:(NSWindow *)window
{
self = [super initWithWindow:window];
if (self) {
// Initialization code here.
}
return self;
}
- (void)windowDidLoad
{
// Set a reference Date
NSCalendar *gregorian = [[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dateComponents = [gregorian components:(NSHourCalendarUnit | NSMinuteCalendarUnit)
fromDate:[NSDate date]];
[dateComponents setSecond:0];
referenceDate = [gregorian dateFromComponents:dateComponents];
currentIndex = 0.0;
// Core Plot
CPTGraph *graph = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
graphView.hostedGraph = graph;
[graph applyTheme:[CPTTheme themeNamed:kCPTPlainBlackTheme]];
//[self setTitleDefaultsForGraph:graph withBounds:bounds];
//[self setPaddingDefaultsForGraph:graph withBounds:bounds];
graph.plotAreaFrame.paddingTop = 15.0;
graph.plotAreaFrame.paddingRight = 15.0;
graph.plotAreaFrame.paddingBottom = 70.0;
graph.plotAreaFrame.paddingLeft = 55.0;
// Grid line styles
CPTMutableLineStyle *majorGridLineStyle = [CPTMutableLineStyle lineStyle];
majorGridLineStyle.lineWidth = 0.75;
majorGridLineStyle.lineColor = [[CPTColor whiteColor] colorWithAlphaComponent:0.5];
CPTMutableLineStyle *minorGridLineStyle = [CPTMutableLineStyle lineStyle];
minorGridLineStyle.lineWidth = 0.25;
minorGridLineStyle.lineColor = [[CPTColor whiteColor] colorWithAlphaComponent:0.1];
// Axes
// X axis
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
x.orthogonalCoordinateDecimal = CPTDecimalFromUnsignedInteger(0);
x.majorGridLineStyle = majorGridLineStyle;
x.minorGridLineStyle = minorGridLineStyle;
x.minorTicksPerInterval = 9;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateStyle = kCFDateFormatterNoStyle;
dateFormatter.timeStyle = kCFDateFormatterMediumStyle;
CPTTimeFormatter *timeFormatter = [[CPTTimeFormatter alloc] initWithDateFormatter:dateFormatter];
timeFormatter.referenceDate = referenceDate;
x.labelFormatter = timeFormatter;
// Y axis
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
y.orthogonalCoordinateDecimal = CPTDecimalFromUnsignedInteger(0);
y.majorGridLineStyle = majorGridLineStyle;
y.minorGridLineStyle = minorGridLineStyle;
y.minorTicksPerInterval = 3;
y.labelOffset = 5.0;
y.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
// Rotate the labels by 45 degrees, just to show it can be done.
x.labelRotation = M_PI * 0.25;
// Create the plot
CPTScatterPlot *dataSourceLinePlot = [[CPTScatterPlot alloc] init] ;
dataSourceLinePlot.identifier = kPlotIdentifier;
dataSourceLinePlot.cachePrecision = CPTPlotCachePrecisionDouble;
CPTMutableLineStyle *lineStyle = [dataSourceLinePlot.dataLineStyle mutableCopy];
lineStyle.lineWidth = 3.0;
lineStyle.lineColor = [CPTColor greenColor];
dataSourceLinePlot.dataLineStyle = lineStyle;
dataSourceLinePlot.dataSource = self;
[graph addPlot:dataSourceLinePlot];
// Plot space
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromDouble(kTimePeriod)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromUnsignedInteger(1)];
plotData = [[NSMutableArray alloc] init];
scrollTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 / kFrameRate
target:self
selector:@selector(scrollPlot:)
userInfo:nil
repeats:YES];
newDataTimer = [NSTimer scheduledTimerWithTimeInterval:3.0
target:self
selector:@selector(newData:)
userInfo:nil
repeats:YES];
}
#pragma mark Test Methods
-(void)scrollPlot:(NSTimer *)theTimer
{
CPTGraph *theGraph = graphView.hostedGraph;
CPTPlot *thePlot = [theGraph plotWithIdentifier:kPlotIdentifier];
if ( thePlot ) {
currentIndex = (-[referenceDate timeIntervalSinceNow])-kTimePeriod;
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)theGraph.defaultPlotSpace;
double location = currentIndex;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(location)
length:CPTDecimalFromDouble(kTimePeriod)];
//[plotData addObject:[NSNumber numberWithDouble:(1.0 - kAlpha) * [[plotData lastObject] doubleValue] + kAlpha * rand() / (double)RAND_MAX]];
//[thePlot insertDataAtIndex:plotData.count - 1 numberOfRecords:1];
}
}
-(void)newData:(NSTimer *)theTimer
{
CPTGraph *theGraph = graphView.hostedGraph;
CPTPlot *thePlot = [theGraph plotWithIdentifier:kPlotIdentifier];
if ( thePlot ) {
DataObj *test = [[DataObj alloc] init];
test.timeInterval = -[referenceDate timeIntervalSinceNow];
test.testValue = rand() / (double)RAND_MAX;
[plotData addObject:test];
[thePlot insertDataAtIndex:plotData.count - 1 numberOfRecords:1];
}
}
#pragma mark Plot Data Source Methods
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
{
return [plotData count];
}
-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
{
NSNumber *num = nil;
DataObj *dataObj = [plotData objectAtIndex:index];
switch ( fieldEnum ) {
case CPTScatterPlotFieldX:
num = [NSNumber numberWithDouble:dataObj.timeInterval];
break;
case CPTScatterPlotFieldY:
num = [NSNumber numberWithDouble:dataObj.testValue];
break;
default:
break;
}
return num;
}
我怎样才能让程序时间准确且 CPU 消耗更少？谢谢。