Drawing an Bar graph on cocoa using core plot

Question

I'm new to mac app development. I'm drawing a bar graph using core plot frame work. What actually i want to is, when i select a month i want to draw graph for last 6 months.when i select '12/2012' I'm able to draw the graph correctly for last 6 months. But when i select '02/2013' the graph is showing only January and February and not the previous months.

- (int)maxVal:(NSMutableArray *)arr {
    NSDictionary *dict  = [arr objectAtIndex:0];
    NSString* dictValue = [dict objectForKey:@"X_VAL"];
    int mxm = [dictValue intValue];
    for (int i=0; i<[arr count]; i++) {
        if ([[[arr objectAtIndex:i] objectForKey:@"X_VAL"] intValue] > mxm) {
            mxm = [[[arr objectAtIndex:i] objectForKey:@"X_VAL"] intValue];
        }
    }
    return mxm;

}


- (int)minVal:(NSMutableArray *)arr {


    int mn = [[[arr objectAtIndex:0] objectForKey:@"X_VAL"] intValue];
    for (int i=0; i<[arr count]; i++) {
        if ([[[arr objectAtIndex:i] objectForKey:@"X_VAL"] intValue] < mn) {
            mn = [[[arr objectAtIndex:i] objectForKey:@"X_VAL"] intValue];
        }
    }
    return mn;
}

- (void)drawGraph {
    if ([graphMutableArray count] > 0) {
        NSRect viewRect = [aGraphView bounds];
        double xAxisStart = 0, yAxisStart = 0, xAxisLength = [graphMutableArray count], yAxisLength = [[graphMutableArray valueForKeyPath:@"@max.Y_VAL"] doubleValue], tenthPartOfYAxis = (yAxisLength + (yAxisLength / 10));
        NSLog(@"Y Axis Length = %f", yAxisLength);
        for (int k = 0; k < xAxisLength; k++) {
            NSDictionary *dict1 = [graphMutableArray objectAtIndex:k];
            NSDictionary *dict2 = [dict1 objectForKey:@"X_VAL"];
            NSDictionary *dict3 = [dict1 valueForKey:@"Y_VAL"];
            NSLog(@"dict 2 = %@ and dict 3 = %@", dict2, dict3);
        }

        graph = [[CPTXYGraph alloc] initWithFrame:viewRect];
        [graph applyTheme:[CPTTheme themeNamed:kCPTSlateTheme]];//kCPTDarkGradientTheme]];//kCPTStocksTheme]];
        aGraphView.hostedGraph = graph;
        graph.plotAreaFrame.masksToBorder = NO;
        graph.paddingLeft = 90.0;
        graph.paddingTop = 20.0;
        graph.paddingRight = 20.0;
        graph.paddingBottom = 70.0;

        // Add plot space for horizontal bar charts
        CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
        plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(xAxisStart)
                                                        length:CPTDecimalFromDouble(xAxisLength + 1)];
        plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(yAxisStart)
                                                        length:CPTDecimalFromDouble(tenthPartOfYAxis)]; 

        CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet;
        CPTXYAxis *x = axisSet.xAxis;
        NSString *cptDecimalstr = [NSString stringWithFormat:@"%f", xAxisLength /[x.axisLabels count]];
        x.majorIntervalLength = CPTDecimalFromString(cptDecimalstr);
        x.minorTicksPerInterval = 1;
        x.majorTickLineStyle = nil;
        x.minorTickLineStyle = nil;
        x.axisLineStyle = nil;
        x.titleLocation = CPTDecimalFromFloat(1.0f);
        x.titleOffset = 55.0f;

       // Define some custom labels for the data elements
        x.labelRotation = M_PI/4;
        x.labelingPolicy = CPTAxisLabelingPolicyNone;   


        NSLog(@"Max = %d and Min = %d", [self maxVal:graphMutableArray], [self minVal:graphMutableArray]);

        NSMutableArray *tempCustomTickLocations = [NSMutableArray arrayWithObjects:[NSNumber numberWithFloat:0.5],[NSNumber numberWithFloat:1.7],[NSNumber numberWithFloat:3.0],[NSNumber numberWithFloat:4.1],[NSNumber numberWithFloat:5.3],[NSNumber numberWithFloat:6.5],[NSNumber numberWithFloat:6.9],[NSNumber numberWithFloat:7.1],[NSNumber numberWithFloat:7.5],[NSNumber numberWithFloat:8.1],[NSNumber numberWithFloat:8.5],[NSNumber numberWithFloat:8.9],nil];

        NSMutableArray *tempMonthsArr = [NSMutableArray arrayWithObjects:@"",@"January", @"February", @"March", @"April", @"May", @"June", @"July", @"August", @"September", @"October", @"November", @"December", nil];


        NSMutableArray *tempMonthsMutArr 
        = [[[NSMutableArray alloc] initWithCapacity:[graphMutableArray count]] autorelease], *tempMutCustomTickLocations 
        = [[[NSMutableArray alloc] initWithCapacity:[graphMutableArray count]] autorelease];

        int k = 0;

        for (int l = [self minVal:graphMutableArray]; l <=[self maxVal:graphMutableArray]; l++) {
            NSString *tempMonth = [tempMonthsArr objectAtIndex:l];
            [tempMonthsMutArr addObject:tempMonth];
            [tempMutCustomTickLocations addObject:[tempCustomTickLocations objectAtIndex:k]];
            k = k + 1;
            NSLog(@"tempMutCustomTickLocations= %@",tempMutCustomTickLocations);
        }

        if ([self minVal:graphMutableArray] == [self maxVal:graphMutableArray]) {
            NSString *tempMonth = [tempMonthsArr objectAtIndex:[self minVal:graphMutableArray]];
            [tempMonthsMutArr addObject:tempMonth];
            [tempMutCustomTickLocations addObject:[tempCustomTickLocations objectAtIndex:0]];
        }


        NSMutableArray *customTickLocations = [NSMutableArray arrayWithArray:tempMutCustomTickLocations];


        NSArray *xAxisLabels = [NSArray arrayWithArray:tempMonthsMutArr];
        NSUInteger labelLocation = 0;
        NSMutableArray *customLabels = [NSMutableArray arrayWithCapacity:[graphMutableArray count]];

        for (NSNumber *tickLocation in customTickLocations) {
            //NSLog(@"tickLocation==%d",tickLocation.intValue);
            CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText: [xAxisLabels objectAtIndex:labelLocation++] textStyle:x.labelTextStyle];
            newLabel.tickLocation = [tickLocation decimalValue];//[tickLocation decimalValue];
            newLabel.offset = x.labelOffset + x.majorTickLength;
           // NSLog(@"[tickLocation floatValue] = %f", [tickLocation floatValue]);
            newLabel.offset = x.labelOffset + x.majorTickLength;
            //NSLog(@"x.labelOffset = %f, x.majorTickLength = %f and newLabel.offset = %f", x.labelOffset, x.majorTickLength, newLabel.offset);
            newLabel.rotation = M_PI/4;
            //NSLog(@"-=-=-=--=-=-=- %f",x.labelOffset);
            //NSLog(@"%f", x.majorTickLength );

            [customLabels addObject:newLabel];
            //NSLog(@"%@",customLabels);

            [newLabel release];
        }

        x.axisLabels =  [NSSet setWithArray:customLabels];
        NSLog(@"%@",x.axisLabels);


        CPTXYAxis *y = axisSet.yAxis;
        y.axisLineStyle = nil;
        y.majorTickLineStyle = nil;
        y.minorTickLineStyle = nil;
        NSString *cptDecimalStr = [NSString stringWithFormat:@"%f", yAxisLength / 10];
        y.majorIntervalLength = CPTDecimalFromString(cptDecimalStr);
        //y.constantCoordinateValue = CPTDecimalFromString(@"0");
        // y.title = @"Y Axis";
        y.titleOffset = 45.0f;
        y.titleLocation = CPTDecimalFromFloat(150.0f);
        //CPTPieChart 

        CPTBarPlot *plot = [[CPTBarPlot alloc] initWithFrame:CGRectZero];
        plot.plotRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0.0)
                                                      length:CPTDecimalFromDouble(xAxisLength)];
        plot.barOffset = [[NSDecimalNumber decimalNumberWithString:@"0.50"]
                          decimalValue]; //CPTDecimalFromDouble(0.50f);

        plot.fill = [CPTFill fillWithColor:[CPTColor lightGrayColor]];
        plot.dataSource = self;

        [graph addPlot:plot ];//toPlotSpace:plotSpace];
    }
    else {

        aGraphView.hostedGraph = nil;
        [[NSAlert alertWithMessageText:@"No Data Found" defaultButton:@"Ok" alternateButton:nil otherButton:nil informativeTextWithFormat:@""] runModal];

    }
}

Can Anyone Help me to solve the problem!!!

Answer 1

You need to update the xRange of the plot space. This will move the axis labels to the correct position and draw data points in the new range. You'll also need to add the new data points to the plot.