How do I use the StackedAreaSeries in the WinRT XAML Toolkit -

i have been trying out charting controls in winrt xam toolkit (https://winrtxamltoolkit.codeplex.com).

i able find examples , cobble working line graph, hoping able make stacked area chart. unfortunately al have managed single dot in corner of blank rectangle.

lets have data alice , bob on has date , balance. want see graph this:-

so can make single set of lines using following xaml , works.

<charting:chart height="400" width="800">     <charting:chart.series>         <charting:lineseries title="alice"                              itemssource="{binding dataforaliceplusbob}"                              independentvaluepath="date"                              dependentvaluepath="balance"                              />         <charting:lineseries title="bob"                              itemssource="{binding dataforbob}"                              independentvaluepath="date"                              dependentvaluepath="balance"                              />     </charting:chart.series> </charting:chart> 

but try might can't figure out how stack alice's data on top of bob's make graph i'm after. far i've gotten, displays single dot, no axis.

<charting:chart height="400" width="800">     <charting:chart.series>          <charting:stackedareaseries>             <charting:stackedareaseries.seriesdefinitions>                 <charting:seriesdefinition title="alice"                                            itemssource="{binding dataforalice}"                                            independentvaluepath="date"                                            dependentvaluepath="balance"                                            />                 <charting:seriesdefinition title="bob"                                            itemssource="{binding dataforbob}"                                            independentvaluepath="date"                                            dependentvaluepath="balance"                                            />             </charting:stackedareaseries.seriesdefinitions>         </charting:stackedareaseries>     </charting:chart.series> </charting:chart> 

just remove tag <charting:chart.series>

this how made stackedareaseries work:

<charting:chart grid.row="1" name="issueschart" width="600" height="400">       <charting:stackedareaseries>          <charting:stackedareaseries.seriesdefinitions>             <charting:seriesdefinition itemssource="{binding dataforalice}"                                         title="loading failures"                                         independentvaluepath="date"                                         dependentvaluepath="balance"/>              <charting:seriesdefinition itemssource="{binding dataforbob}"                                         title="ingestion failures"                                         independentvaluepath="date"                                         dependentvaluepath="balance"/>           </charting:stackedareaseries.seriesdefinitions>        </charting:stackedareaseries> </charting:chart>