JAVAFX CHARTS: Setting origin point on category axis -

i in need add 0 point category axis in javafx line chart. in image want "t0" represent 0 mark of origin on x axis, can mark point on y axis on chart. sample line chart ( looks bar chart !)

i'm not clear you're asking, if want pixel coordinates of left end of x-axis, can do

category xaxis = ... ;  // ...  double leftend = xaxis.getdisplayposition(value0) - xaxis.getcategoryspacing(); 

where value0 x-value of first data point.