hi,

i want to be able to tell bar charts to start from zero.

drawBarChart() has an option, AroundZero, which extends "zero" values down to the bottom of the graph.
this option, when set on data which has zero-values, makes them appear to be -2 (or -10 or whatver your y-scale reads as).

please provide an option to force zero as the first y-value (that is, disable y-value padding).

an update:

ive found that bar charts start counting their y-axis from the lowest common value across all data, minus a further 2 integers. am i right?

i propose changing this so the user can choose two y-start options: either zero, or the actual lowest value across all data.

Hi mykchan,

I've modified the rendering layout so 0 values now appears as a straight 1px height line on bar charts.

I'm not sure to fully understand what you intend to do, the 2px border may be a side effect of the AA algorithm or the rounded border boxes. Can you please show me the bit of code you're working on? This will help me to figure out where to search ;o)

Thank you!
JD.

thanks for your quick reply! i really appreciate the work you put into this library.

im sorry, i dont know how to describe the problem im having. hopefully this illuminates it.

here is the image of the chart:



and here is the exact code used to generate the image above:

http://pastebin.com/dhXeTX3D

thanks to the 2nd post in http://wiki.pchart.net/forum/viewtopic.php?f=3&t=28 i figured it out:

to force the y-axis to start from zero, one must tell the chart:
$chart->drawScale(array('Mode' => SCALE_MODE_START0));