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Re: used by LogLogPlot?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg130515] Re: used by LogLogPlot?
  • From: Bill Rowe <readnews at sbcglobal.net>
  • Date: Wed, 17 Apr 2013 02:33:21 -0400 (EDT)
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  • Delivered-to: l-mathgroup@wolfram.com
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On 4/16/13 at 12:36 AM, fishe053 at cougars.csusm.edu wrote:

>I'm confused too.  I'm trying to plot this code below via
>mathematica however I can't get the plot to come out correctly.

>R = 10;
>L = 0.01;
>C = 2.533e-8;
>f = logspace(3,5,2000);
>w = 2*pi*f;
>H = R./(R+j*w*L + 1./(j*w*C ));
>semilogx(f,20*log10(abs(H)))

>I've tried using LogLinearPlot to replicate it in mathematica but
>when I try I get something completely different!  Not sure why.

Simply put you must use correct syntax.

Do not get in the habit of using a single upper case letter as a
variable. Too many of these have built-in meaning for
Mathematica and using one that has built-in meaning generally
results in undesired behavior. A short (but not complete) list
of upper case letters with built-in meaning include C, D, E, I
and N

All built-in Mathematica functions/commands/symbols start with
an upper case letter. That is 3.1459... is Pi not pi, the
logarithm of x base 10, is Log[10,x] not log10(x)

A consequence of this is anything that begins with a lower case
letter is an undefined symbol that you have to define. That is j
is not the Sqrt[-1] unless you specifically define it to be.

The characters "(" and ")" are used only to group things and
cannot be used to mark function arguments. That is

log10(x) is seen by Mathematica as the product of symbols log10
and x.






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