[ferret_users] irregularly decreasing x-axis

[Sujata Mandke <amin@xxxxxxxxxxxxxx>]

Dear Ferret users
   I am beginner to ferret.

I had searched Users guide, email archives but did not 
find solution to the problem.

My problem is as follows:

   Using ascii data file with data in two columns, 
i am plotting a line plot. 

The values in the first column should be plotted on 
x-axis. The values in the second column is to be 
plotted as line graph. The x-axis values provided in the
first column increases irregularly.

I wish to plot x-axis values in decreasing order  
of magnitude as indicated below:

32, 16, 8, 4, 2, 1, 0.5  

 which  should be equally spaced  on the x-axis.
(The decreasing order is such that each value is 
half of its previous. It is not monotonically decreasing)

As i was unable to plot x-axis values in the decreasing order
 mentioned above, i had written script for line plot,
 with x-axis increasing regularly.

I am reproducing below the script i have used for the purpose.
------------------------------------------------------------------
test.jnl

file/var="xcor,-" test.dat
define axis/x/from_data/name=xax xcor
define grid/x=xax gt
file/var="xcor,power"/grid=gt test.dat
plot/line/symbol=20/HLIMITS=32.00:0.5/nolab power
--------------------------------------------------

How shall i  change this script for x-axis 
decreasing irregularly, in the way mentioned above.

Regards
Dr. Sujata Mandke
Scientist, CGMD, Indian Institute of Tropical Meteorology
PUNE,INDIA.