Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Python: How to get my variables out of a function

  1. Sep 12, 2008 #1
    1. The problem statement, all variables and given/known data

    The exercise: Make a Python function for computing
    g(t) = e**(-a * t**2) and gderiv(t) = -2*a*t*g(t)

    Return the function values of g(t) and gderiv(t). Apply the function to write out a result in the format:
    g(1, a=0.5)=0.606531, g’(1, a=0.5)=-0.606531

    I have made a function g(t, a) and gderiv(t,a), but I dont know how to print t and a so that i can print the result in the format: "g(1, a=0.5)=0.606531, g’(1, a=0.5)=-0.606531"

    3. The attempt at a solution

    from math import e

    def g(t, a):
    G = e**(-a*t**2)
    Gderiv = -2*a*t*G
    return G, Gderiv,

    G,Gderiv = g(t = 1, a = 0.5)

    print "g(%g, a=%g) = %.6f" % (t, a, G)

    Edit: The problem is that t and a are not defined.
  2. jcsd
  3. Sep 12, 2008 #2


    User Avatar
    Homework Helper
    Gold Member

    I've never done any programming in python, but I assume that there is an input function which allows the user of your program to input the values of t and a... I'd try something like this:
    Code (Text):
    from math import e

    def g(t, a):
        G = e**(-a*t**2)
        Gderiv = -2*a*t*G
        return G, Gderiv

    t=input("Please input value of t   ")  
    a=input("Please input value of a   ")

    G,Gderiv = g(t , a )

    print "g(%g, a=%g) =  %.6f" % (t, a, G)
    print "g'(%g, a=%g) =  %.6f" % (t, a, Gderiv)
    And then when you run the program you input the values of t and a when prompted.
  4. Sep 12, 2008 #3
    Thank you
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook