request for member 'constantCoordinateValue' in something not a structure or union error in core plot

i am trying to draw bar chart for my app using core plot as give on here

http://code.google.com/p/core-plot/source/browse/examples/CPTestApp-iPhone/Classes/CPTestAppBarChartController.m?r=1dcee044c4981113f38b3445880c88da14bdb40e开发者_JAVA技巧

i am getting error for

CPXYAxisSet *axisSet = (CPXYAxisSet *)barChart.axisSet;
CPXYAxis *x = axisSet.xAxis;  
x.constantCoordinateValue = CPDecimalFromString(@"0");  

error is coming for above line

error: request for member 'constantCoordinateValue' in something not a structure or union and same error for following

y.constantCoordinateValue = CPDecimalFromString(@"0");  

i hope some know how to solve this

thank you in advance

use this

x.orthogonalCoordinateDecimal = CPDecimalFromString(@"0");

instead

x.constantCoordinateValue = CPDecimalFromString(@"0");