[Edu-sig] thought re graphing calculators ...
Gregor Lingl
gregor.lingl at aon.at
Mon Sep 28 22:30:45 CEST 2009
Brian Blais schrieb:
> On Sep 27, 2009, at 19:38 , Charles Cossé wrote:
>
>> Hi, this has probably been discussed to death already, but maybe not:
>> The point at which fancy graphing calculators become "necessary" (ie
>> as in one's student career) is the point at which the calculator
>> should be abandoned and Python employed. Just a thought ... delete
>> at will !
>
> Just a month ago, a friend of mine who homeschools her children was
> asking me about graphing calculators. Apparently the math curriculum
> she uses has a number of graphic calculator exercises. My advice was
> to buy a nice solar-powered scientific calculator (for $15 at Target),
> but to ignore the graphing calculator entirely. Her kids should do
> the exercises by hand, on graph paper instead. Anything that is hard
> enough for you to use a graphic calculator can be done much more
> easily with a computer.
>
> After giving her this advice (which I still stand by), I was thinking
> about my own experience. I was going through high school when the
> first graphic calculators came out, and I had one Junior and Senior
> year and through college. I loved to program it, and I loved the big
> screen where I could see and edit expressions. However, as I think
> about it, I can not think of a single problem where I *needed* the
> graphic calculator, or where it gave me more insight than I could do
> by hand.
Hi Brian,
I think I have a counterexample.
Run the script, that you can find here:
http://svn.python.org/view/*checkout*/python/branches/release26-maint/Demo/turtle/tdemo_chaos.py?revision=73559&content-type=text%2Fplain
(or below.) Runs with Python 2.6 or later.
It certainly could be mimicked on
a (programmable) graphics calculator.
What do you think?
Regards,
Gregor
# File: tdemo_chaos.py
# Author: Gregor Lingl
# Date: 2009-06-24
# A demonstration of chaos
from turtle import *
N = 80
def f(x):
return 3.9*x*(1-x)
def g(x):
return 3.9*(x-x**2)
def h(x):
return 3.9*x-3.9*x*x
def jumpto(x, y):
penup(); goto(x,y)
def line(x1, y1, x2, y2):
jumpto(x1, y1)
pendown()
goto(x2, y2)
def coosys():
line(-1, 0, N+1, 0)
line(0, -0.1, 0, 1.1)
def plot(fun, start, colour):
pencolor(colour)
x = start
jumpto(0, x)
pendown()
dot(5)
for i in range(N):
x=fun(x)
goto(i+1,x)
dot(5)
def main():
reset()
setworldcoordinates(-1.0,-0.1, N+1, 1.1)
speed(0)
hideturtle()
coosys()
plot(f, 0.35, "blue")
plot(g, 0.35, "green")
plot(h, 0.35, "red")
# Now zoom in:
for s in range(100):
setworldcoordinates(0.5*s,-0.1, N+1, 1.1)
return "Done!"
if __name__ == "__main__":
main()
mainloop()
> It was a fun toy, but not the best tool.
>
>
>
> bb
>
>
>
> --
> Brian Blais
> bblais at bryant.edu <mailto:bblais at bryant.edu>
> http://web.bryant.edu/~bblais <http://web.bryant.edu/%7Ebblais>
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Edu-sig mailing list
> Edu-sig at python.org
> http://mail.python.org/mailman/listinfo/edu-sig
>
More information about the Edu-sig
mailing list