Assignment 20 – function implementation

Due Monday, October 24

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Task

• Implement module hodge.py

• Use program podge.py to perform some simple (but not exhaustive) testing of the module.

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Module hodge.py

• Function summation( n )

• Function parameter n is an integer value.

• The function returns the sum of the integers.

1 + ... + n.

• The function does not produce output or request input.

• A run of of the tester should produce output

summation( 5 ): 15

summation( 1 ) : 1

summation( 0 ): 0

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• Function sample( d )

• The function has a single decimal parameter d, which is a carbon-12 to carbon-14 decay ratio. The function returns an integer estimate of the age of a fossil with a such a ratio. The carbon-14 decay formula for estimating age is:

-8268.3982 * log( d )

• Important piece of information: The module contains a statement that acquires function log() from the standard library math. The effect of the statement is that within module hodge, log() can be used as if it was a built-in function.

from math import log

Because the age is an estimate, it is always truncated to integer. I suspect the built-in int() function should prove useful.

• The correct output of podge testing for the function is below.

sample( 0.35 ) = 8680

sample( 0.005 ) = 43808

sample( 1.0 ) = 0

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• Function has_vowel( w )

• The function has a single string parameter w. The function returns the logical value True, if w contains a lowercase vowel; that is, it has at least one occurence of 'a', 'e', 'i', 'o', or 'u'. If instead, w does not contain a lowercase vowel, the function returns the logical value False.

• The correct output of podge testing for the function is below.

has_vowel( ox ) = True

has_vowel( eel ) = True

has_vowel( pug ) = True

has_vowel( mink ) = True

has_vowel( cat ) = True

has_vowel( lynx ) = False

 

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