#14 drawScale autoscaling with small datarange

[Dylan Nelson]

drawScale() has trouble calculating the appropriate number of divisions when the datarange is small. i.e.:

( $this->VMax - $this->VMin ) = 3.0

but with a large plot s.t. $MaxDivs = 10 or 20 for instance. The problem is that the /* Compute automatic scaling */ section starts with a constant $Factor. In this example the resulting $Divisions is 3, but we would like it to be much higher (looks terrible on a big plot). A fix is:

/* Compute automatic scaling */

$ScaleOk = FALSE; $Factor = 1;

$MinDivHeight = 25; $MaxDivs = ($this->GArea_Y2 - $this->GArea_Y1) / $MinDivHeight;

while ( (( $this->VMax - $this->VMin ) / $Factor) < $MaxDivs/5.0 )
$Factor /= 5.0;

which makes $Factor appropriately small for a good starting guess. Not sure if this is robust.