Core Plot extremely slow on iOS? - ios

I am having issues with a simple X/Y scatter plot with Core Plot 2.0 on iOS 7.1
The following plot code:
CPTGraphHostingView* graphHostView;
CPTXYGraph* graph;
CPTScatterPlot* plot;
CPTXYPlotSpace* plotSpace;
DebugLog(#"Initializing GRAPH HOST VIEW");
graphHostView = [[CPTGraphHostingView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];
[self addSubview: graphHostView];
// Create a CPTGraph object and add to hostView
graph = [[CPTXYGraph alloc] initWithFrame:graphHostView.bounds];
graphHostView.hostedGraph = graph;
// Get the (default) plotspace from the graph so we can set its x/y ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
// Note that these CPTPlotRange are defined by START and LENGTH (not START and END) !!
[plotSpace setYRange: [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat( 0 ) length:CPTDecimalFromFloat( 20000 )]];
[plotSpace setXRange: [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat( 0 ) length:CPTDecimalFromFloat( 6 )]];
// Create the plot (we do not define actual x/y values yet, these will be supplied by the datasource...)
plot = [[CPTScatterPlot alloc] initWithFrame:CGRectZero];
plot.dataSource = dataSource;
[graph addPlot:plot toPlotSpace:graph.defaultPlotSpace];
takes just about 60 seconds to complete grinding at 100% CPU usage, and allocating steadily up to 300 MB RAM. What could be up? The graph is being hosted in a "parent" UIView.
I have used Core Plot before, and while it seemed slow, this is clearly totally unacceptably slow! What could be the cause of this?

I solved this by using dispatch_async when updating my graph. For example, in my code i Used:
dispatch_async(dispatch_get_main_queue(), ^{
[self setupGraph];
});
I hope this helps.

Related

Scrolling through data only in core plot iOS

Currently I'm using core plot cocoa pod to draw a scatter graph, currently I need scrolling to be enabled but at the same time I need the x & y axis the be fixed on the corner of the screen and only move through data any way to do this ?.
My current implementation for the following code makes me scrolls through data but x-axis or y-axis disappears when I scroll far through the graph
-(void) viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
CPTGraphHostingView* hostView = [[CPTGraphHostingView alloc] initWithFrame:self.view.frame];
[self.view addSubview: hostView];
// Create a CPTGraph object and add to hostView
CPTGraph* graph = [[CPTXYGraph alloc] initWithFrame:hostView.bounds];
hostView.hostedGraph = graph;
// Get the (default) plotspace from the graph so we can set its x/y ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
plotSpace.allowsUserInteraction=YES;
// Note that these CPTPlotRange are defined by START and LENGTH (not START and END) !!
[plotSpace setYRange:[CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:10]]];
[plotSpace setXRange:[CPTPlotRange plotRangeWithLocation:[NSNumber numberWithInt:0] length:[NSNumber numberWithInt:10]]];
plotSpace.delegate = self;
graph.paddingLeft = 10.0;
graph.paddingRight = 10.0;
graph.paddingTop = 10.0;
graph.paddingBottom = 10.0;
// Create the plot (we do not define actual x/y values yet, these will be supplied by the datasource...)
CPTScatterPlot* plot = [[CPTScatterPlot alloc] initWithFrame:CGRectZero];
// Let's keep it simple and let this class act as datasource (therefore we implemtn <CPTPlotDataSource>)
plot.dataSource = self;
// Finally, add the created plot to the default plot space of the CPTGraph object we created before
[graph addPlot:plot toPlotSpace:graph.defaultPlotSpace];
}
Thanks in advance :)
Use the axisConstraints:
x.axisConstraints = [CPTConstraints constraintWithRelativeOffset:0.0];
y.axisConstraints = [CPTConstraints constraintWithRelativeOffset:0.0];
Use 0.0 to place the axis to the left (y-axis) or bottom (x-axis). Use 1.0 to place the axis to the right (y-axis) or top (x-axis). Any fraction between 0.0 and 1.0 is valid.

CorePlot multiple scatterplots huge memory consumption

I'm experiencing some problems with CorePlot. I try to plot multiple scatterPlots into one graph. Which works as expected but when I start scrolling or zooming the graph the whole app increases it's memory usage up to 900MB an crashes. I think I have to do some object releasing but I don't know how. Basically I plot each line with a different plot identifier and put the according data into the datasource.
Here is what I got: (In this example code I just reduced the axe ranges with static values for testing purposes.)
- (void)setupGraph {
// Create graph from theme
self.graph = [[CPTXYGraph alloc] initWithFrame:self.scatterPlotView.bounds];
self.graph.plotAreaFrame.masksToBorder = NO;
self.scatterPlotView.hostedGraph = self.graph;
CPTTheme *theme = [CPTTheme themeNamed:kCPTPlainBlackTheme];
[self.graph applyTheme:theme];
self.graph.paddingLeft = 0.0;
self.graph.paddingTop = 0.0;
self.graph.paddingRight = 0.0;
self.graph.paddingBottom = 0.0;
// Setup plot space
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.allowsUserInteraction = YES;
plotSpace.delegate = self;
plotSpace.globalXRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0) length:CPTDecimalFromDouble(30)];
plotSpace.globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0) length:CPTDecimalFromDouble(15)];
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0) length:CPTDecimalFromDouble(10)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0) length:CPTDecimalFromDouble(15)];
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
CPTXYAxis *y = axisSet.yAxis;
x.labelingPolicy = CPTAxisLabelingPolicyNone;
y.labelingPolicy = CPTAxisLabelingPolicyNone;
}
This method loads my data and draws the scatterplots
- (void)loadSignals {
//Data loading logic goes here nothing special just one array for each plot
for (Signal *sig in [signals allValues]) {
[self constructScatterPlot:sig.name];
}
}];
This is where the drawing happens:
- (void)constructScatterPlot:(NSString *)identifier {
CPTScatterPlot *dataSourceLinePlot = [[CPTScatterPlot alloc] init];
CPTMutableLineStyle *lineStyle = [dataSourceLinePlot.dataLineStyle mutableCopy];
CPTScatterPlot *boundLinePlot = [[CPTScatterPlot alloc] init];
boundLinePlot.identifier = identifier;
lineStyle = [boundLinePlot.dataLineStyle mutableCopy];
lineStyle.miterLimit = 1.0;
lineStyle.lineWidth = 1.0;
lineStyle.lineColor = [CPTColor redColor];
boundLinePlot.dataLineStyle = lineStyle;
boundLinePlot.dataSource = self;
boundLinePlot.cachePrecision = CPTPlotCachePrecisionDouble;
boundLinePlot.interpolation = CPTScatterPlotInterpolationStepped;
[self.graph addPlot:boundLinePlot];
}
...and this is where the datasource gets it's values:
-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
{
NSString *plotIdent = (NSString *) plot.identifier;
if (![plotIdent isEqualToString:self.currentIdent]) {
self.countPlot++;
self.currentIdent = plotIdent;
}
Signal *newSig = [self.signals objectForKey:plotIdent];
Value * newValue = [newSig valueAtTime:index];
NSNumber *number = [NSNumber numberWithInteger:[newValue.value integerValue]];
if ( fieldEnum == CPTScatterPlotFieldY ) {
return number;
}
if ( fieldEnum == CPTScatterPlotFieldX ) {
return [NSNumber numberWithInteger:index];
}
return nil;
}
So first of all I'd like to know if this is the correct way of drawing multiple plots (up to 40 in my case) into one graph? If so, what could I do to optimize my plot performance?
The output should look like this:
I found this use
"try setting collapsesLayers to YES on the hosting view"
Application get stuck when drawing nearly 40 Scatter Plots using Core Plot in IPad
Each plot is a CALayer that covers the entire plot area of the graph, so with 40 of them you may be using up most of the available video memory. If they all use the same line style, you can plot all of the lines on the same plot and save some memory that way. Insert an extra data point between the line segments and return nil or #(NAN) from the datasource to break the line.

Initialize the default zoom

When my scatter plot appears, I see that :
But I would like to se that :
Directly after chart loading, I want that the user see a chart with all data displaying, and not just a small piece like in the first screenshot. How can I define the original "zoom" ?
EDIT : (here's my code)
[...]
CPTGraph *graph = self.hostView.hostedGraph;
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
CPTScatterPlot *myPlot = [[CPTScatterPlot alloc] init];
myPlot.dataSource = self;
myPlot.delegate = self;
CPTColor *myColor = [CPTColor greenColor];
[graph addPlot:myPlot toPlotSpace:plotSpace];
myPlot.plotSymbolMarginForHitDetection = 10.0f;
[plotSpace scaleToFitPlots:[NSArray arrayWithObject:myPlot]];
CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy];
[xRange expandRangeByFactor:CPTDecimalFromCGFloat(DynamicValue)];
plotSpace.xRange = xRange;
CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
[yRange expandRangeByFactor:CPTDecimalFromCGFloat(DynamicValue)];
plotSpace.yRange = yRange;
[...]
Many of the Core Plot example apps use -[CPTPlotSpace scaleToFitPlots:] to adjust the plot ranges to the plot data. If you already know the data range, you set the plot space xRange and/or yRange directly when setting up the graph.

Core Plot Bar Graph Y-Axis issues

I am trying to make a bar graph with core plot. I cannot get the y-axis to scale properly or the tick-marks in the correct places. My biggest issue is that if I set:
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDEcimalFromFloat(0) length:CPTDecimalFromFloat(max_value);
And max_value is anything higher then 10 it takes an unreasonable amount of time for the graph to load. For example I need max_value to be around 1000 to show the tops of all the values but when I set it to 1000 it takes over 15 seconds to load the screen. But if I leave it set to 10 my bar graphs take up the entire screen and you cannot see the top.
This is the rest of the part of the code dealing with this. Any advice would be appreciated.
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0)
length:CPTDecimalFromFloat(1000)];
[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:_liftOffPlot,_sideLeanPlot,_forwardLeanPlot,_crossLegsPlot,nil]];
graph.plotAreaFrame.borderLineStyle = nil;
axisSet.yAxis.title = #"times completed";
axisSet.yAxis.titleTextStyle = axisTitleStyle;
axisSet.yAxis.titleOffset = -25.0f;
axisSet.yAxis.axisLineStyle = nil;
axisSet.yAxis.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
axisSet.yAxis.preferredNumberOfMajorTicks = 10;
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTickLocations = nil;
axisSet.yAxis.majorTickLocations = nil;
axisSet.yAxis.title = #"times completed";
axisSet.yAxis.titleTextStyle = axisTitleStyle;
axisSet.yAxis.titleOffset = -25.0f;
axisSet.yAxis.axisLineStyle = nil;
axisSet.yAxis.majorIntervalLength = CPTDecimalFromString(#"100");
axisSet.yAxis.orthogonalCoordinateDecimal = CPTDecimalFromString(#"0");
axisSet.yAxis.visibleRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0) length:CPTDecimalFromInt(1000)];
axisSet.yAxis.gridLinesRange = axisSet.yAxis.visibleRange;
As I seem to be finding with most things xcode, it is all about where you put your code. If I have CPTPlotRange:PlotRangeWithLocation:Length before I do my set up it is really slow and buggy. If instead I add it to the end of my code after setting the other values for the axises suddenly there is only a very minor delay. I actually got this code originally from a tutorial and modified it to fit what I needed but I guess the tutorial didn't have the same delay because the length of the data was much lower.
So all I did to fix this problem was put the following code after my axis set up instead of before;
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0)
length:CPTDecimalFromFloat(1000)];
[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:_liftOffPlot,_sideLeanPlot,_forwardLeanPlot,_crossLegsPlot,nil]];
graph.plotAreaFrame.borderLineStyle = nil;

Weird border on Core Plot Pie Chart

Why is Core Plot drawing these two lines?
This is how I'm setting up the graph:
// setup the pie chart
graph = [[CPTXYGraph alloc] initWithFrame:[_pieView bounds]];
[_pieView setHostedGraph:graph];
CPTPieChart *pieChart = [[CPTPieChart alloc] init];
[pieChart setDataSource:self];
[pieChart setPieRadius:75.0];
[pieChart setIdentifier:#"PieChart1"];
[pieChart setStartAngle:M_PI_4];
[pieChart setSliceDirection:CPTPieDirectionClockwise];
[graph addPlot:pieChart];
(_pieView is the CPTGraphHostingView*)
How do I remove the two black lines? I tried doing what's described in How do remove the border around a core-plot graph, to no avail.
That's not a border—it's the default axes that come with a CPTXYGraph. It's one line of code to remove them:
graph.axisSet = nil;

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