--- In "Ray" <> wrote:
>
> I am new to this list, so maybe I am missing something, but
> what is wrong with just compiling gnuplot for your target.
>
> I am running debian on TS7400 just installed gnuplot it seems
> to work fine although you have to output to a file, since I
> have no X. (actually no video display).
>
> Should be ok for a web server if that's what you are doing.
> Also since you are just visualizing some data, speed is not an
> issue. Not like doing some compute intensive graphics..
>
thanks for your thoughts Ray.
good to know gnuplot installs without issues. However if you look at
my earlier post you'll see I'm doing more that just visualising.
I have used gnuplot to do linear regression fitting of logrithmic
calibration curves to some thermistor data. I sample several data
channels and use the log fn on the fly to convert that resistance
data to temperature as it's plotted. I have also pursuaded gnuplot to
do a trapezoidal area under graph integral and plot that finally
fitting a polynomial to the resulting data.
In fact I was amazed I could do all that with gnuplot which claims to
do no more than plot data.
This is pretty fast on the desktop machine , Athlon XP at 2.3GHz, but
it's not instantaeous. I doubt I will be able to do the same thing
with a larger data set from automatic sampling on a slow CPU using
very slow software FP emulation.
I was also using CVS gnuplot which may well have some dependancy
issues with the rather "historic" feature set of the std TSlinux
distribution.
It appears that I would need to move to current stable Debian with a
2.6 kernel, this would at least give kernel fp emu and possibly even
crunch support (if it can be limitted to using the bits that work
;) ). However, all this would probably be far more work that
recoding what I've done.
BTW, what version of gnuplot is it?
Thx.
> On the subject of fixed vs float wars, I am firmly on the side of
> fixed point, although I have written my own floating point
> libraries in assembler (many years ago). The only time you
> **REALLY** need floating point for realtime is when a variable
> has a very large dynamic range, and those instances are fairly
> rare.
I quite agree, but I ain't about to recode gnuplot in fixed point ;)
I may try to recalibrate using a polynomial or dig out a series
approx to the log function that can be done in fixed point. The
regression fit can be done once only and can take it's time.
The plotting should be pretty straighforward and could be done much
more efficiently that using a generalised tool like gnuplot.
>Nowadays it seems everything has hardware floating point
> and as a result it becomes the easy way out.
>
> Meantime, try compiling something like
>
> float x,y,z;
> x=123.456;
> y=567.890;
> z = x*y;
> printf("z=%f\n",z);
>
> I would be surprised if it didn't work..... :-)
>
>
> Hope this helps.
>
> Regards Ray
>
>
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