Displaying the Y inversed

[Itamar]

I have information that needs to be displayed where 1 is the top of the axis
and everything higher than 1 is below (for example alexa rank) is it possible?

[lbayuk]

There is no direct way to do this. I can't even think of how it might be
implemented, since so much depends on the axis direction. However, you can
'simulate' it by (1) inverting and offsetting the data, and (2) using a custom
Y label format function to display the 'fake' values. Here is a quick stand-
alone example. Note: This forum isn't friendly for copying and pasting code
(Sourceforge knows about it but has not chosen to do anything) - someday I
will set something better up for this purpose. Sorry.

<?php
# Simulated inversion of Y axis
require_once 'phplot.php';

# The original data:
$data = array(
  array('A', 3),
  array('B', 2),
  array('C', 1),
  array('D', 4),
  array('E', 8),
);

# Offset and invert the data:
$offset = 11; // Must be bigger than all values
foreach ($data as &$row) $row[1] = $offset - $row[1];
unset($row); // See PHP manual on foreach with references

$p = new PHPlot;
$p->SetTitle('Invert Y axis');
$p->SetDataType('text-data');
$p->SetDataValues($data);
$p->SetPlotType('bars');
$p->SetXTickPos('none');
$p->SetYLabelType('custom', create_function('$y', "return ($offset-\$y);"));
$p->SetPlotAreaWorld(NULL, 0, NULL, $offset-1);

$p->DrawGraph();