Good question TS20, I agree with you.
I like how that user set up that graph.
It takes the min and max baro values of the last 24 hour (more or less) as reference for the axis.
But how do you change that in…
baro_24hr.php
// Create the graph. These two calls are always required
$graph = new Graph($xsize,$ysize,“auto”,30);
$graph->SetScale(“textlin”);
$graph->yscale->SetAutoMin($pres_automin);
$graph->yscale->SetAutoMax($pres_automax);
$graph->SetMarginColor(“$margincolour”);
$graph->SetShadow();
$graph->SetMargin($lm,$rm,$tm,$bm);