The horizontal position of the item relative to the canvas in pixels.
<button> <caption> <checkboxes> <clock> <dropdown> <image> <likert> <listbox> <openended> <picture> <radiobuttons> <shape> <slider> <slidertrial> <text> <textbox> <video>
Use the xpct propert to get the position of the item as a percentage of the canvas width.
The following displays the value of xpx in a text stimulus:
<text sometext>
/ items= ("xpx = <% text.foo.xpx %>")
</text>