Re: [Phys-l] Grapher on macintosh

[ludwik kowalski <kowalskil@mail.montclair.edu>]

Sorry, it was me who made a typing error. Unfortunately, I do not know  
what it was; the Grapher file was not saved. Now all is as you  
describe. The Grapher works fine for me so far. But learning by trial  
and error is not very efficient. That is why I am looking for a good  
tutorial. Offering an application without offering a good tutorial is  
only 50% of work.

Ludwik

On Feb 22, 2008, at 11:45 PM, Steve Highland wrote:

> > I was showing that the curve plotted by Grapher was in very
> > good agreement with the function posted by Steven. I suspect there  
> > was
> > a typing error in his right side expression. The only place the x  
> > axis
> > is intercepted is at the origin.  The values of y increase
> > monotonically for all values of x.
>
> There was no typo -- the function I was trying to plot was indeed
>
> Y = -(9/98)(x^2 - 28x)
>
> Which has a maximum of y=18 at x=14 and then goes back to zero at  
> x=28.
>
> My goof was not realizing Grapher had chosen non-traditional minor  
> tick
> units.  Now I see that "4 tick marks per major tick" is referring to  
> just
> the marks themselves rather than the number of subdivisions between  
> major
> ticks.  That's what messed me up -- I put "5" in the box and didn't  
> see that
> it gave me six subdivisions.
>
> Now I have it plotted correctly *and* looking right, too.
>
> Steve
>
> > On Feb 22, 2008, at 3:26 PM, Steve Highland wrote:
> >
> > > I spent some hours one day trying to get Grapher to work for me last
> > > year.
> > > It was painful. Perhaps I can dig up some knowledge for you (but
> > > don't hold
> > > your breath).
> > >
> > > One very disturbing thing about Grapher is that I've found it does  
> > > not
> > > accurately plot functions relative to the grid marks!  I tried to
> > > plot a
> > > piecewise continuous function and the pieces did not match up!
> > >
> > > Even worse, just try to plot this:
> > >
> > > Y = -(9/98)(x^2 -28x)
> > >
> > > This came out of a football kick problem I was trying to help out
> > > with on
> > > Yahoo Answers.  It should have a maximum of y = 18 at x = 14 and it
> > > should
> > > cross the x-axis at x=28.
> > >
> > > Whoa -- I was about to complain that the plot doesn't hit the grid
> > > marks,
> > > but now I (finally!) see that there are SIX subdivisions for every
> > > FIVE
> > > units on my plot.  Egad!  How in the world does something like that
> > > come up
> > > automatically?  I suffered greatly a few months ago over this but
> > > didn't see
> > > it till now.  Yikes.
> >
> > I do not know why my file, attached to two messages, was not part of
> > what I received. Is this because this file was extracted from Grapher
> > or is it because I am having a problem with sending attachments. As a
> > test let me attach a file that has nothing to do with Grapher. See
> > below.
> >
> > The attached rtf file should appear below this line
> >
> >
> >
> >
> >
> > Ludwik Kowalski, a retired physisist
> > 5 Horizon Road, apt.2702, Fort Lee, NJ, 07024, USA
> > Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/
> >
> >
> >
> >
> > _______________________________________________
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>
>
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Ludwik Kowalski, a retired physisist
5 Horizon Road, apt.2702, Fort Lee, NJ, 07024, USA
Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/