wpf - Error in references -

i not sure why there error in references. oxyplot.wpf.lineseries oxyplot.series.series best overloaded method match system.collections.objectmodel.collection.add(oxyplot.axes.axis) has invalid arguments.

using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using oxyplot; using oxyplot.wpf; using oxyplot.axes;  namespace points {    public class psdtest     {        public static plotmodel filteringinvalidpoints()        {            var plotmodel1 = new plotmodel();            plotmodel1.title = "filtering invalid points";            var linearaxis1 = new linearaxis();            linearaxis1.position = axisposition.bottom;            linearaxis1.title = "x-axis";            plotmodel1.axes.add(linearaxis1);            var linearaxis2 = new linearaxis();            linearaxis2.title = "y-axis";            plotmodel1.axes.add(linearaxis2);            var lineseries1 = new lineseries();            lineseries1.title = "nan";            lineseries1.points.add(new datapoint(double.nan, double.nan));            lineseries1.points.add(new datapoint(1, 0));            lineseries1.points.add(new datapoint(2, 10));            lineseries1.points.add(new datapoint(double.nan, 20));            lineseries1.points.add(new datapoint(3, 10));            lineseries1.points.add(new datapoint(4, 0));            lineseries1.points.add(new datapoint(4.5, double.nan));            lineseries1.points.add(new datapoint(5, 0));            lineseries1.points.add(new datapoint(6, 10));            lineseries1.points.add(new datapoint(double.nan, double.nan));            lineseries1.points.add(new datapoint(7, 0));            lineseries1.points.add(new datapoint(double.nan, double.nan));            plotmodel1.series.add(lineseries1);            var lineseries2 = new lineseries();            lineseries2.title = "positiveinfinity";            lineseries2.points.add(new datapoint(double.positiveinfinity, double.positiveinfinity));            lineseries2.points.add(new datapoint(1, 1));            lineseries2.points.add(new datapoint(2, 11));            lineseries2.points.add(new datapoint(double.positiveinfinity, 20));            lineseries2.points.add(new datapoint(3, 11));            lineseries2.points.add(new datapoint(4, 1));            lineseries2.points.add(new datapoint(4.5, double.positiveinfinity));            lineseries2.points.add(new datapoint(5, 1));            lineseries2.points.add(new datapoint(6, 11));            lineseries2.points.add(new datapoint(double.positiveinfinity, double.positiveinfinity));            lineseries2.points.add(new datapoint(7, 1));            lineseries2.points.add(new datapoint(double.positiveinfinity, double.positiveinfinity));            plotmodel1.series.add(lineseries2);            var lineseries3 = new lineseries();            lineseries3.title = "negativeinfinity";            lineseries3.points.add(new datapoint(double.negativeinfinity, double.negativeinfinity));            lineseries3.points.add(new datapoint(1, 2));            lineseries3.points.add(new datapoint(2, 12));            lineseries3.points.add(new datapoint(double.negativeinfinity, 20));            lineseries3.points.add(new datapoint(3, 12));            lineseries3.points.add(new datapoint(4, 2));            lineseries3.points.add(new datapoint(4.5, double.negativeinfinity));            lineseries3.points.add(new datapoint(5, 2));            lineseries3.points.add(new datapoint(6, 12));            lineseries3.points.add(new datapoint(double.negativeinfinity, double.negativeinfinity));            lineseries3.points.add(new datapoint(7, 2));            lineseries3.points.add(new datapoint(double.negativeinfinity, double.negativeinfinity));            plotmodel1.series.add(lineseries3);            return plotmodel1;        }      } } 

it sounds you're running issues different namespaces. can't entirely understand you're attempting, may not give desired result, able code compile using following namespaces (having installed oxyplot.wpf via nuget):

using oxyplot; using oxyplot.axes; using oxyplot.series; 

it may case doesn't you, if turns out you're after specific behaviour found in oxyplot.wpf namespace.