Pentaho: logarithmic scale in charts - pentaho

Question

Is there a way to set a "logarithmic scale" in a Pentaho chart?
Result from my sql query has a very wide range (from 1 to 1000000).
I could change my sql query to something like this:
"Select LOG(10, wide_value)..."
But Y-axis scale changes the same way at Pentaho chart (1,2,3...). I need the original labels on Pentaho chart (10,100,1000...).
What I found on web are old forums talking about that this is still a feature request, or to try with "CCC" (too much documentation for something too simple) or to modify the source code (even worse). None of them useful.
Hint: I'm using a legacy implementation on Pentaho bi-server 6.0. If there is an option on newer versions it will be useful too, maybe there is something similar on my old version.

Answer 1

This is the solution in case someone else needs it.
My query originally delivered something like:
Select
   x_axis as "x_axis",
   y_axis_wide_value as "value"
From ...
It must be modified to:
Select
x_axis as "x_axis",
LOG(10, y_axis_wide_value) as "value"
From ...
My graphic in Pentaho's "Components Panel" is a "CCC Line Chart".
What I needed is for the Y axis to show the real values. That is achieved as follows:
In "Advanced Properties" you must locate "OrthoAxisThickFormatter" and enter the following function:
function fun (value)
{
     return Math.pow (10, value);
}
Some additional settings for better viewing:
orthoAxisOriginIsZero: false
orthoAxisZeroLine: false
And that was all. Now my graphs are displayed with logarithmic scale.