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Re: Problem with a plot in Mathematica

  • To: mathgroup at smc.vnet.net
  • Subject: [mg100481] Re: Problem with a plot in Mathematica
  • From: Bill Rowe <readnews at sbcglobal.net>
  • Date: Fri, 5 Jun 2009 03:03:00 -0400 (EDT)

On 6/4/09 at 3:32 AM, donatomirabile at hotmail.com (dmirab) wrote:

>Hi there I have a function to plot in Mathematica but i am keeping
>getting some mistake of sintax.

>this is the function:

>C=(25/2*3.14*7*vary*varz)*exp(-y^2/2*vary^2)*exp(-38^2/2*varz^2)

>and

>vary=0.22*(1+0.0004x)-0.5 varz=0.20*(1+0.0001x)-0.5

>it shoud be a 3d but i put z=38 so it's a 2D now. How do you type it
>in Mathematica?

To make effective use of any software, it is a good idea to read
the documentation. And for software as complex as Mathematica,
this is essential.

A couple of key points. All built-in functions and symbols used
by Mathematica start with a capital letter. Consequently,
anything that does not begin with a capital letter is something
you created and must be defined by you.

Second, computer software generally doesn't do context
interpretation well. Meaning, you simply cannot use parenthesis
pairs as both indicating grouping for multiplication and
delimiting function arguments. In fact, given both functions and
variables can have arbitrary names, I doubt there is any way to
create software that could allow such overloading. To overcome
this, square brackets are used by Mathematica to delimit
function arguments. So, your function needs to be written as:

C=(25/2*3.14*7*vary*varz)*Exp[-y^2/2*vary^2]*Exp[-38^2/2*varz^2]



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