Python Math libraries - How to?
Hi, I am a very newbie who would very much appreciate some hints.
Python 2.52. on Windows XP for now. Soon on Ubuntu 8
I am teaching myself Python following free tutorials. I can solve
problems using arithmetic, but when I try to upgrade the programs
using math libraries nothing seems to work. I downloaded a 2002
tutorial from Zelle "An Introduction to Computer Science" where he
uses a "import math" statement to calculate a square root. I tried the
"pi" library function but it didn´t work. I tried using def Pi() it
did not work either. I am yet to find a tutorial that explains how to
declare (or initialize) and pass numbers to the functions such as
"cos(x)" and the pi which does not have a variable in it. Is just a
constant.
Here is the arithmetic program I made that it worked before I added
the "import math" line. I erased the constant p = 3.1416 and added
the "i" for the library function "pi" in the algorithms. But I get an
error message not recognizing "pi"
#volumen.py
# A program to compute the volume and surface area of a sphere
import math
def main():
print "This program calculates the volume and surface area of a
sphere"
print
r = input("Please enter the radious: ")
print
r3 = r*r*r
volume = 4/3*pi*r3
r2 = r*r
surface = 4*pi*r2
print "The Volume is", volume, " Cubic centimeters"
print
print "The Surface area is", surface, " square centimeters"
main()
*** Error message *
Traceback (most recent call last):
File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 20, in
main()
File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 13, in main
volume = 4/3*pi*r3
NameError: global name 'pi' is not defined
--
http://mail.python.org/mailman/listinfo/python-list
Python Math libraries - How to?
Hi, I am a very newbie who would very much appreciate some hints.
Python 2.52. on Windows XP for now. Soon on Ubuntu 8
I am teaching myself Python following free tutorials. I can solve
problems using arithmetic, but when I try to upgrade the programs
using math libraries nothing seems to work. I downloaded a 2002
tutorial from Zelle "An Introduction to Computer Science" where he
uses a "import math" statement to calculate a square root. I tried the
"pi" library function but it didn´t work. I tried using def Pi() it
did not work either. I am yet to find a tutorial that explains how to
declare (or initialize) and pass numbers to the functions such as
"cos(x)" and the pi which does not have a variable in it. Is just a
constant.
Here is the arithmetic program I made that it worked before I added
the "import math" line. I erased the constant p = 3.1416 and added
the "i" for the library function "pi" in the algorithms. But I get an
error message not recognizing "pi"
#volumen.py
# A program to compute the volume and surface area of a sphere
import math
def main():
print "This program calculates the volume and surface area of a
sphere"
print
r = input("Please enter the radious: ")
print
r3 = r*r*r
volume = 4/3*pi*r3
r2 = r*r
surface = 4*pi*r2
print "The Volume is", volume, " Cubic centimeters"
print
print "The Surface area is", surface, " square centimeters"
main()
*** Error message *
Traceback (most recent call last):
File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 20, in
main()
File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 13, in main
volume = 4/3*pi*r3
NameError: global name 'pi' is not defined
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python Math libraries - How to?
Hi, thak you. I get the following: > > > *** Error message * > > > Traceback (most recent call last): > > File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 20, > > in > > > > main() > > File "C:/Python25/z - MIS PROGRAMAS/volumen-b.py", line 13, > > in main > > volume = 4/3*pi*r3 > > NameError: global name 'pi' is not defined -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Math libraries - How to?
> > Thank you. I´ll try all methods to figure out the convenience of each Adolfo > > -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Math libraries - How to?
Thank you :-), I´ll do Adolfo > > pi is not a global name. When you do "import math",you aren't adding > everything to the name space, you are just telling python that you are > going to be using that file. You then refer to it as math.*, such as > "math.pi", or "math.pow(r,3)". To use it the way you want to, you > would have to do "from math import pi" instead of "import math" -- http://mail.python.org/mailman/listinfo/python-list
