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y=f(x,{A1,A2,A3...})

Posted: Tue Aug 31, 2004 1:45 pm
by sailwave
Hi,

I am playing with your evaluation copy at the moment. Very nice. I having trouble figuring out if I can do what I need to do through.

I want to plot this function for various values of A (say A= 10,20,30,40,50,60,70,80,90,100).

y = 101 + 1000 * log10(A/x)

With x moving between 1 and A (step 1) for each plot.

I can do it by hand by repeatedly changing A and the limit of x (to the value of A) by hand but would like to automate it if possible.

Can I do that?

(If nothing else if would be useful to be able to refer to constants in the x limit field.)

The reason I need to automate it is that I need to generate hundreds of graphs like this.

Nice program.

Posted: Tue Aug 31, 2004 2:16 pm
by sailwave
Ah... the macro editor?

Posted: Tue Aug 31, 2004 2:51 pm
by DPlotAdmin
The macro editor won't help here; there are no loop structures (other than cycling through all files matching a specification) and no variables. This is something I've toyed around with a bit but haven't yet been happy with the results. Perhaps it will make it into a future release, but it will likely be a while before that happens.

If you're reasonably proficient with Visual Basic or some other language, or if you are comfortable with Excel's VBA, you can fairly easily set the problem up and use DPLOTLIB.DLL to do what you want. If you have any questions about that just let me know.

Posted: Tue Aug 31, 2004 3:07 pm
by sailwave
OK, thanks; I'll keep looking for something...

NB: y = e^(-x) says "invalid argument at x=1", with 1 <= x <= 100.

Posted: Tue Aug 31, 2004 3:13 pm
by DPlotAdmin
NB: y = e^(-x) says "invalid argument at x=1", with 1 <= x <= 100.
Since DPlot doesn't allow for a constant named e I'm guessing you want the inverse natural logarithm of x. Use "y=exp(-x)"

Posted: Tue Aug 31, 2004 3:22 pm
by sailwave
Ah, OK. I mistakingly assumed that since there was no "E" field, it was implicitly taken...

Posted: Tue Aug 31, 2004 4:26 pm
by DPlotAdmin
Just an FYI - E isn't used as a constant simply because it's too confusing for the parser to distinguish between a constant E and scientific notation E, i.e. 1.5E+4