# Python: How to get my variables out of a function

1. Sep 12, 2008

### MaxManus

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. Sep 12, 2008

### gabbagabbahey

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.

3. Sep 12, 2008

Thank you