Question

有没有办法可以使用coreplot scatterplot x-axis和epochtime？这是我使用的情节范围。

     plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(1329375688) length:CPTDecimalFromFloat(100)];

我正在从文件中读取纪元值。

 -(void)plot1{

  // Start with some simple sanity checks before we kick off
     if ( (self.scatterPlotView1 == nil) || (self.graphData == nil)) {
    NSLog(@"TUTSimpleScatterPlot: Cannot initialise plot without scatterPlotView1 or    data.");
    return;
}

if ( (self.graph != nil)  ) {
    NSLog(@"TUTSimpleScatterPlot: Graph object already exists.");
    return;
}

// Create a graph object which we will use to host just one scatter plot.

CPTTimeFormatter *dateTimeFormatterForXAxis;

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init]; 
[formatter setMaximumFractionDigits:0];  


_graph=[[CPTXYGraph alloc] initWithFrame:CGRectMake(0,500,750,500)];

self.scatterPlotView1.hostedGraph = _graph;

// Add some padding to the graph, with more at the bottom for axis labels.
self.graph.plotAreaFrame.paddingTop = 20.0f;
self.graph.plotAreaFrame.paddingRight = 10.0f;
self.graph.plotAreaFrame.paddingBottom = 30.0f;
self.graph.plotAreaFrame.paddingLeft= 35.0f;

// Tie the graph we've created with the hosting view.
self.scatterPlotView1.hostedGraph = self.graph;

// If you want to use one of the default themes - apply that here.
[self.graph applyTheme:[CPTTheme themeNamed:kCPTPlainWhiteTheme]];

// Create a line style that we will apply to the axis and data line.
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
CPTMutableLineStyle *gridStyle = [CPTMutableLineStyle lineStyle];
CPTMutableLineStyle *plotStyle = [CPTMutableLineStyle lineStyle];
lineStyle.lineColor = [CPTColor redColor];
lineStyle.lineWidth = 2.0f;
gridStyle.lineColor = [CPTColor redColor];
gridStyle.lineWidth = 1.0f;
plotStyle.lineColor = [CPTColor blackColor];
plotStyle.lineWidth = 1.0;    

// Create a text style that we will use for the axis labels.
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"Helvetica";
textStyle.fontSize = 14;
textStyle.color = [CPTColor blackColor];

// Create the plot symbol we're going to use.
CPTPlotSymbol *plotSymbol = [CPTPlotSymbol ellipsePlotSymbol];
plotSymbol.lineStyle = plotStyle;
plotSymbol.size = CGSizeMake(2.0, 2.0);
// Setup some floats that represent the min/max values on our axis.
float xAxisMin = 0;
float xAxisMax = 10;
float yAxisMin = 0;
float yAxisMax = 100;




// We modify the graph's plot space to setup the axis' min / max values.
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(1329375688) length:CPTDecimalFromFloat(500)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(yAxisMin) length:CPTDecimalFromFloat(yAxisMax - yAxisMin)];

// Modify the graph's axis with a label, line style, etc.
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
axisSet.xAxis.visibleRange =[CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(yAxisMin) length:CPTDecimalFromDouble(yAxisMax)];
axisSet.yAxis.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(yAxisMin) length:CPTDecimalFromDouble(yAxisMax)];


axisSet.xAxis.title = @"Time(per sec)";
axisSet.xAxis.titleTextStyle = textStyle;
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.xAxis.titleOffset = 30.0f;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.minorTickLineStyle = lineStyle;
axisSet.xAxis.majorGridLineStyle = lineStyle;
axisSet.xAxis.minorGridLineStyle=gridStyle;
axisSet.xAxis.gridLinesRange = axisSet.xAxis.visibleRange;
axisSet.xAxis.labelOffset = 6.0f;
axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(2.0f);
axisSet.xAxis.minorTicksPerInterval = 5;
axisSet.xAxis.minorTickLength = 10.0f;
axisSet.xAxis.majorTickLength = 7.0f;
axisSet.xAxis.labelTextStyle = textStyle;
axisSet.xAxis.labelFormatter = formatter;



axisSet.yAxis.title = @"Uterus Ccontraction";
axisSet.yAxis.titleTextStyle = textStyle;
axisSet.yAxis.titleOffset = 20.0f;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyle;
axisSet.yAxis.labelTextStyle = textStyle;
axisSet.yAxis.labelFormatter = formatter;
axisSet.yAxis.majorGridLineStyle= lineStyle;
axisSet.yAxis.minorGridLineStyle=gridStyle;
axisSet.yAxis.gridLinesRange = axisSet.yAxis.visibleRange;


axisSet.yAxis.labelOffset = 3.0f;
axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat(10.0f);
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTickLength = 5.0f;
axisSet.yAxis.majorTickLength = 7.0f;

// Add a plot to our graph and axis. We give it an identifier so that we
// could add multiple plots (data lines) to the same graph if necessary.
CPTScatterPlot *plot = [[CPTScatterPlot alloc] init];
plot.dataSource = self;
plot.identifier = @"mainplot";
plot.dataLineStyle = plotStyle;
plot.plotSymbol = plotSymbol;
//[self.graph reloadData];
[self.graph setNeedsDisplay];
[self.graph addPlot:plot];

}


   //Delegate method that returns the number of points on the plot
 -(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
   {
if ( [plot.identifier isEqual:@"mainplot"] )
{
    return [self.graphData count];
}

return 0;
   }


     -(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:    (NSUInteger)index 
   {
    if ( [plot.identifier isEqual:@"mainplot"] )
      {
    //NSValue *value = [self.graphData objectAtIndex:index];
    //CGPoint point = [value CGPointValue];

    if(self.scatterPlotView1){
    NSDictionary *entry = [self.graphData objectAtIndex:index];
    CGFloat x = [[entry objectForKey:@"X"] floatValue];
    CGFloat y = [[entry objectForKey:@"Y"] floatValue];
    CGPoint point = CGPointMake(x, y);


    // FieldEnum determines if we return an X or Y value.
    if ( fieldEnum == CPTScatterPlotFieldX )
    {
        return [NSNumber numberWithFloat:point.x];
    }
    else    // Y-Axis
    {
        return [NSNumber numberWithFloat:point.y];
    }
    } else  if(self.scatterPlotView2){
            NSDictionary *entry = [self.graphData objectAtIndex:index];
            CGFloat x = [[entry objectForKey:@"X"] floatValue];
            CGFloat z = [[entry objectForKey:@"Y"] floatValue];
            CGPoint point1 = CGPointMake(x, z);


            // FieldEnum determines if we return an X or Y value.
            if ( fieldEnum == CPTScatterPlotFieldX )
            {
                return [NSNumber numberWithFloat:point1.x];
            }
            else    // Y-Axis
            {
                return [NSNumber numberWithFloat:point1.y];
            }


    }
}

return [NSNumber numberWithFloat:0];
}

当我设置如上所述的xaxis绘图范围时，我最终获得了一个浓缩图。是因为我将情节范围视为浮动吗？

Answer 1

这是一个有效的情节范围。没有更多信息，很难判断它是否代表了预期的范围。

对添加的代码的评论：你在数据源中做了很多不必要的工作。如果您有大量数据，这将对您的绘图性能产生负面影响。尝试这样的事情：

NSDictionary *entry = [self.graphData objectAtIndex:index];
switch ( fieldEnum ) {
case CPTScatterPlotFieldX:
    return [entry objectForKey:@"X"];
    break;
case CPTScatterPlotFieldY:
    return [entry objectForKey:@"Y"];
    break;
}

在X轴核心图上使用Epoch时间

1 个答案: