VPython Functions: Difference between revisions
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Written by Kevin Randrup | |||
Introduction to functions in Python and applying them to write shorter and more understandable code. | Introduction to functions in Python and applying them to write shorter and more understandable code. | ||
== | ==Summary== | ||
Functions at a high level are used to perform a certain task. Functions can accept a number of inputs (also "arguments" or "parameters") and can give back 0 or 1 output values. Furthermore, they make code much easier to understand by encapsulating a task in a single line of code instead of | |||
==Basic Functions== | ==Basic Functions== | ||
===Basic Python function syntax=== | ===Basic Python function syntax=== | ||
Functions can be defined with the def keyword followed by the function name and a colon. | |||
Functions can be defined with the | |||
The <code>return</code> keyword can be used for a function to "give back" a result. | The <code>return</code> keyword can be used for a function to "give back" a result. | ||
| Line 32: | Line 27: | ||
result = addNumbers(1, 2, 4) | result = addNumbers(1, 2, 4) | ||
== | ==Code Reuse== | ||
Writing a function for a task instead of copy and pasting code makes your program much easier to understand and debug. The best way to illustrate this is with an example. | |||
For this example, we will create a function to calculate the electric field created by a point charge. | |||
As a reminder, this is the formula we are modeling | |||
<math></math> | |||
# Calculates the eletric field at a given vector away from the charge | |||
def eletricField(q, r): | |||
eletricConstant = 9e9 # 1/(4 * pi * ε0) | |||
return eletricConstant * q * r.norm() / r.mag2 | |||
Revision as of 17:14, 5 December 2015
Written by Kevin Randrup
Introduction to functions in Python and applying them to write shorter and more understandable code.
Summary
Functions at a high level are used to perform a certain task. Functions can accept a number of inputs (also "arguments" or "parameters") and can give back 0 or 1 output values. Furthermore, they make code much easier to understand by encapsulating a task in a single line of code instead of
Basic Functions
Basic Python function syntax
Functions can be defined with the def keyword followed by the function name and a colon.
The return keyword can be used for a function to "give back" a result.
def functionName(argumentOne, argumentTwo):
functionReturnValue = argumentOne + argumentTwo
return functionReturnValue
Example function
# This function adds three numbers together and gives back the result using the return keyword
def addNumbers(a, b, c):
return a + b + c
Example use of a function
# Calls the function addNumbers with the arguments 1, 2 and 4 result = addNumbers(1, 2, 4)
Code Reuse
Writing a function for a task instead of copy and pasting code makes your program much easier to understand and debug. The best way to illustrate this is with an example.
For this example, we will create a function to calculate the electric field created by a point charge. As a reminder, this is the formula we are modeling [math]\displaystyle{ }[/math]
# Calculates the eletric field at a given vector away from the charge
def eletricField(q, r):
eletricConstant = 9e9 # 1/(4 * pi * ε0)
return eletricConstant * q * r.norm() / r.mag2
See also
Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?
Further reading
Books, Articles or other print media on this topic
External links
Phython colors: http://matplotlib.org/examples/color/named_colors.html
References
This section contains the the references you used while writing this page http://matplotlib.org/examples/color/named_colors.html n?