qt - Qwt QwtScaleEngine -

i have qwtplot. plot autoscalable limit distention avoid plot extended between 46.5 , 47.5. example, plot wasn't extented on less of 5 unites.

i know must use qwtscaleengine don't how ?

seems, have no need use qwtscaleengine try kind of code:

plot=new qwtplot(parent); plot->setaxisautoscale(qwtplot::yleft,false); plot->setaxisscale(qwtplot::yleft,minyborder,maxyborder,0); 

qwtscaleengine better in use formatting like:

class timescaledraw:public qwtscaledraw{ public:     timescaledraw(qstring fmt):format(fmt){}     virtual         qwttext label(double v) const{     return (qdatetime::frommsecssinceepoch(floor(v))).tostring(format);    } private:     const           qstring format; };