DBD_Chart Can't take log of

From: Bart Van den Bergh (bvdb_at_pandora.be)
Date: 06/29/04 

Date: 29 Jun 2004 02:35:35 -0700

Hello,

I having trouble generating graphs with the DBD-Chart 0.80 module,
when values from a select out of an Oracle database are between 0 and
1. If I (for example) use this range of values to draw a graph:

TO_CHAR(D1.TME_ST D2.VALUE-D1.VALUE
----------------- -----------------
June 10 2004 .06
June 11 2004 .05
June 11 2004 .06
June 11 2004 .06
June 12 2004 .06
June 13 2004 .05
June 13 2004 .06
June 13 2004 .06
June 14 2004 .06
June 15 2004 .05
June 15 2004 .06
June 15 2004 .06
June 16 2004 .06
June 17 2004 .05
June 17 2004 .06
June 17 2004 .06
June 18 2004 .06
June 19 2004 .05
June 19 2004 .06
June 19 2004 .06
June 20 2004 .06
June 21 2004 .05
June 21 2004 .06
June 21 2004 .06
June 22 2004 .06

I get this error:

Tk::Error: Can't take log of -2e+038 at C:/Perl/site/lib/DBD/Chart/Pl
ot.pm line 1583.
 DBD::Chart::Plot::computeRanges at C:/Perl/site/lib/DBD/Chart/Plot.pm
line 1583

 DBD::Chart::Plot::computeScales at C:/Perl/site/lib/DBD/Chart/Plot.pm
line 1387

 DBD::Chart::Plot::plot at C:/Perl/site/lib/DBD/Chart/Plot.pm line
1261
 DBD::Chart::st::execute at C:/Perl/site/lib/DBD/Chart.pm line 2889
 main::storage at C:\Perl\code\dbacap.pl line 1004
 main::getcare at C:\Perl\code\dbacap.pl line 3308
 [\&main::getcare]
 Tk callback for .frame3.button
 Tk::__ANON__ at C:/Perl/site/lib/Tk.pm line 228
 Tk::Button::butUp at C:/Perl/site/lib/Tk/Button.pm line 111
 (command bound to event)

this is the select I used to build the graph:

SELECT LINEGRAPH FROM clog WHERE WIDTH=1000 AND HEIGHT=300 AND
Y_AXIS='Size (MB)' AND X_AXIS='Date' AND TITLE = 'Tablespace Growth'
AND SHOWGRID=0 AND SHOWPOINTS = 0 AND SHOWVALUES=0 AND
BACKGROUND='transparent'

and also when I have a range of values where all of them are 0, I get
this message:

Tk::Error: Can't take log of 0 at C:/Perl/site/lib/DBD/Chart/Plot.pm
line 1583.
 DBD::Chart::Plot::computeRanges at C:/Perl/site/lib/DBD/Chart/Plot.pm
line 1583

 DBD::Chart::Plot::computeScales at C:/Perl/site/lib/DBD/Chart/Plot.pm
line 1387

 DBD::Chart::Plot::plot at C:/Perl/site/lib/DBD/Chart/Plot.pm line
1261
 DBD::Chart::st::execute at C:/Perl/site/lib/DBD/Chart.pm line 2889
 main::performance at C:\Perl\code\dbacap.pl line 2539
 main::getcare at C:\Perl\code\dbacap.pl line 3309
 [\&main::getcare]
 Tk callback for .frame3.button
 Tk::__ANON__ at C:/Perl/site/lib/Tk.pm line 228
 Tk::Button::butUp at C:/Perl/site/lib/Tk/Button.pm line 111
 (command bound to event)

this is the select used to build the graph:
SELECT LINEGRAPH FROM clog WHERE WIDTH=1000 AND HEIGHT=300 AND
Y_AXIS='Ratio (%)' AND X_AXIS='Date' AND SHOWGRID=0 AND SHOWPOINTS = 0
AND SHOWVALUES=0 AND BACKGROUND='transparent'

Are these known problems or am I doing something wrong? Thanks for any
input!

Kind regards,
Bart