Error with datlin scale and all Y axis data values negative

[Simon Dakin]

Just in case anyone monitors this group.

This works:

$graph->SetScale('datlin');

$plot = new LinePlot(array(-1,2,-1), array(time(), time()+60, time()+120));

But this shows the data correctly bur doesn't produce anything on the X axis scale:

$graph->SetScale('datlin');

$plot = new LinePlot(array(-1,-2,-1), array(time(), time()+60, time()+120));

The problem appears to be with the fact that all of the Y axis data values are negative.

A fix would be great.