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1. Vivek Guest

## Logarithmic Chart

I need a Java based charting libary JFC/Swing (preferably free) which supports
natural logarithmic scales(ln, log e)
on both X & Y axes. I tried many web sites KavaChart, NetChart, JCLass etc.
But nobody seems to be supporting
log e axis (some are supporting log10 but not ln). If anybody come across
such a library please let me know?

2. Paul Clapham Guest

## Re: Logarithmic Chart

As you may or may not remember from your math courses, ln(x) =
ln(10)*log10(x). So converting between log10 and ln is simply multiplying
by a constant. This may provide you with a workaround.

PC2

Vivek <vivekbp@yahoo.com> wrote in message news:39cf6149\$1@news.devx.com...
>
> I need a Java based charting libary JFC/Swing (preferably free) which

supports
> natural logarithmic scales(ln, log e)
> on both X & Y axes. I tried many web sites KavaChart, NetChart, JCLass

etc.
> But nobody seems to be supporting
> log e axis (some are supporting log10 but not ln). If anybody come across
> such a library please let me know?

3. vivek Guest

## Re: Logarithmic Chart

Thanks Paul. But I am not sure whether it will be suitable as the Graph drawn
will not (visually) match the actual
data. It would have been better if I had got a chart which supported natural
logarithmic scales. Maybe I will
try this as the last resort if I cannot get a chart that supports natural
logarithmic scales

Vivek

"Paul Clapham" <pclapham@core-mark.com> wrote:
>As you may or may not remember from your math courses, ln(x) =
>ln(10)*log10(x). So converting between log10 and ln is simply multiplying
>by a constant. This may provide you with a workaround.
>
>PC2
>
>Vivek <vivekbp@yahoo.com> wrote in message news:39cf6149\$1@news.devx.com...
>>
>> I need a Java based charting libary JFC/Swing (preferably free) which

>supports
>> natural logarithmic scales(ln, log e)
>> on both X & Y axes. I tried many web sites KavaChart, NetChart, JCLass

>etc.
>> But nobody seems to be supporting
>> log e axis (some are supporting log10 but not ln). If anybody come across
>> such a library please let me know?

>
>

4. Modestas Guest

## Re: Logarithmic Chart

Hi,

You may try my MonarchCharts (www.monarch.com) They still do not support
logarithmic scales, but they have notion of AxisMappers. By defining a custom
axis mapper, you will easily get what you want.

Good luck
Modestas

5. Guest

## Re: Logarithmic Chart

"Vivek" <vivekbp@yahoo.com> wrote:
>
>I need a Java based charting libary JFC/Swing (preferably free) which supports
>natural logarithmic scales(ln, log e)
> on both X & Y axes. I tried many web sites KavaChart, NetChart, JCLass

etc.
>But nobody seems to be supporting
>log e axis (some are supporting log10 but not ln). If anybody come across
>such a library please let me know?

you might referene JavaPro, September 2000. There was an article for JRuler.
From it,
and the other posts about logarithms, you could place your tick marks appropriately.

The July issue of C/C++ Users Journal, www.cuj.com also had an article on
data based axes

6. Amit Sinha Guest

## Re: Logarithmic Chart

I have a slightly different problem. I have developed a simple chart and I
am using it inside an applet. I want to save the chart object as a jpg/png
file on the server. Could someone please advise me how to do this? THanks.

AKS

7. rlachape Guest

## Re: Logarithmic Chart

"Amit Sinha" <amitksinha@hotmail.com> wrote:
>
>I have a slightly different problem. I have developed a simple chart and

I
>am using it inside an applet. I want to save the chart object as a jpg/png
>file on the server. Could someone please advise me how to do this? THanks.
>
>AKS

Assuming you know how to draw your chart into an offscreen image instead
of a panel,
here's one way to write the image object to a jpg file (where 'tempname'
is the filename).
I used this code using Sun's Java sdk 1.2 and sdk 1.3.

import java.awt.geom.AffineTransform;
import com.sun.image.codec.jpeg.*;

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