In case anyone is still wondering, I figured this out. The proper syntax is either: y=2{0.5,1.0}x^2-x-2 which generates two parabolas, or: y=2{0.5, 0.6, ..., 1.0}x^2-x-2 which generates six, as shown here<http://www.mrob.com/users/dasimov/20101113-grapher-1.png> . You can also put the braces in more than one place, like this: y=2{0.5, 0.6, ..., 1.0}x^2-x+{-2, -1, ..., 2} which generates a graph with 30 parabolas. It warns you first with a confirmation dialog ("This operation create a large set of graphs with many different parameter values (30), and will take a while to complete. Do you want to continue?"). And yes, it says "create", not "creates". Note that you will not see the "^" in the display, but you type it in order to get an exponent. Also, you hit the right-arrow to "exit the exponent" before typing "-x" and the rest. The "Grapher" program is included with Mac OS X 10.4 through 10.6 (I don't know about earlier versions) and is in the Utilities folder along with a bunch of other cool stuff hardly anyone knows about :-) The screen shot is from a Power Mac G5, but it works the same way on my 8-core Nehalem Mac Pro under Mac OS 10.6. - Robert Munafo On Sat, Nov 13, 2010 at 15:16, Dan Asimov <dasimov@earthlink.net> wrote:
Does any other math-funnik use the Mac Grapher utility?
It can do so many things to create a 2D or 3D image . . . BUT it is buggy as hell. At least the version that came with my Mac -- among the very last with a Motorola chip -- plus all Apple updates to my software.
It was, I think, created in a story that is now legendary among programmers: < http://www.pacifict.com/Story/ >.
But I sure wish they would debug the *&^%$@ thing.
Case in point: Just now I wanted to draw a family of plane curves with a simple parametric equation depending on one additional parameter . . . for six values of that parameter. Grapher supposedly has a syntax for doing this: just stick the additional parameter in curly brackets, and either explicitly write all parameter values, or the first two and the last one.
In my case, according to the examples and the (very sparse) Help file, that should appear as either
{0.5, 0.6, 0.7, 0.8, 0.9, 1.0}
or
{0.5, 0.6...1.0},
respectively. But neither one works.
Boiled down: Using either {1.0} or {0.5} my tiny Grapher program draws the correct curve. But using {0.5, 1.0} instead, it draws two curves that are both wrong!
Has anyone figured how to get around stupid bugs like this?
--Dan
-- Robert Munafo -- mrob.com Follow me at: mrob27.wordpress.com - twitter.com/mrob_27 - youtube.com/user/mrob143 - rilybot.blogspot.com