Question

I have downloaded CorePlot_0.9 from google and imported in my iPhone project. I want to draw line(ScatterPlot) in iphone app. I just reviewed and copy the code from 'CPTTestApp-iPhone' CPTTestAppScatterPlotController class and run the project it working very good. But, i want to change the chart values. I tried my level best but, i can’t find where i need to give the values and how the scatterplot values show in the graph. Here is the code,

    This is in ViewDidLoad
    {
// Create a green plot area
    CPTScatterPlot *dataSourceLinePlot = [[[CPTScatterPlot alloc] init] autorelease];
    CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
    lineStyle.lineWidth = 5.f;
    lineStyle.miterLimit = 1.0f;
    lineStyle.lineWidth = 3.0f;
    lineStyle.lineColor = [CPTColor blackColor];
    lineStyle.dashPattern = [NSArray arrayWithObjects:[NSNumber numberWithFloat:0.0f], [NSNumber numberWithFloat:0.0f], nil];
    dataSourceLinePlot.dataLineStyle = lineStyle;
    dataSourceLinePlot.identifier = @"Green Plot";
    dataSourceLinePlot.dataSource = self;

     // Add some initial data
            NSMutableArray *contentArray = [NSMutableArray arrayWithCapacity:100];
            NSUInteger i;
            for ( i = 0; i < 20; i++ )
            {
                id x = [NSNumber numberWithFloat:0+i*0.5];//1+i*0.05
                //NSLog(@"Rand_Max : %d", RAND_MAX);//Rand_Max : 2147483647
                id y = [NSNumber numberWithFloat:3.2*rand()/(float)RAND_MAX+0.2];//1.2*rand()/(float)RAND_MAX + 1.2
                [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]];
            }
            dataForPlot = contentArray;
    }

    #pragma mark -
    #pragma mark Plot Data Source Methods

    -(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot 
    {
        return [dataForPlot count];
    }

    -(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index 
    {
        NSLog(@"NumberForPlot calling");
        NSNumber *num = [[dataForPlot objectAtIndex:index] valueForKey:(fieldEnum == CPTScatterPlotFieldX ? @"x" : @"y")];
        // Green plot gets shifted above the blue
        if ([(NSString *)plot.identifier isEqualToString:@"Green Plot"])
        {
            if ( fieldEnum == CPTScatterPlotFieldY ) 
                num = [NSNumber numberWithDouble:[num doubleValue] + 0.0];
        }
        return num;
    }

Please help where i need to give the values to change the values appear in graph? And also give me suggestion how can i change the values dynamically for the graph? Thanks in advance. Please help me.

Answer 1

I have created a method like -(void) drawScatterPlot; and wrote the code to draw the scatter plots in that method like this below,

{
// Create a green plot area
    CPTScatterPlot *dataSourceLinePlot = [[[CPTScatterPlot alloc] init] autorelease];
    CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
    lineStyle.lineWidth = 5.f;
    lineStyle.miterLimit = 1.0f;
    lineStyle.lineWidth = 3.0f;
    lineStyle.lineColor = [CPTColor blackColor];
    lineStyle.dashPattern = [NSArray arrayWithObjects:[NSNumber numberWithFloat:0.0f], [NSNumber numberWithFloat:0.0f], nil];
    dataSourceLinePlot.dataLineStyle = lineStyle;
    dataSourceLinePlot.identifier = @"Green Plot";
    dataSourceLinePlot.dataSource = self;

     NSMutableArray *contentArray = [[NSMutableArray alloc] init]; 
   NSUInteger i;
   for ( i = 0; i < 4; i++ )
     {
    int xVal = [[customTickLocations objectAtIndex:i] intValue];
    id x = [NSNumber numberWithInt:xVal];

    int yVal = [[scatterValuesArray objectAtIndex:i] intValue];
    id y = [NSNumber numberWithInt:yVal];

    NSLog(@"X and Y in content Array Loop : %@ , %@", x , y);
    [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]];
      }
            dataForPlot = contentArray;
 }

And i reload this method while when am getting new real time values.

Thanks.