List comprehension

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Christian Lawson-Perfect 1 year, 11 months ago

Published this.

○

Chris Graham 3 years, 2 months ago

Created this.

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Question statement

Consider an array of random numbers in the range $[0,1]$ , created with:

{code_block("import numpy as np\nx = np.random.rand(100)",["language":"python"])}

Give any introductory information the student needs.

			Name	Type	Generated Value

Automatically regenerate variables?

No variables have been defined in this question.

Parts

Code

Code

Ask the student a question, and give any hints about how they should answer this part.

Use list comprehension to set y to the elements in the array that are greater than $0.5$

Help with this part type

Marks

Show correct answer on reveal?

Show score feedback icon?

Show the input hint?

Code language

The language that the student's code will be written in.

Correct answer

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y = [ a for a in x if a > 0.5]

A correct answer to the part.

Substitute question variables into the correct answer?

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Placeholder

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# Assume that x is already set 
y = 

Initial text for the code editor

Student code modifier

​x
 
​

JME expression to modify the student's submitted code before being passed to the marking template. The student's code is available as the string variable studentAnswer.

Preamble

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import numpy as np
x = np.random.rand(100)

This code is run before the student's code. Define anything that the student's code or your tests need.

Postamble

​

This code is run after the student's code but before the validation and unit tests.

Format postamble output as code?

If ticked, any output produced by the postamble will be formatted in monospace font, with whitespace preserved. If not ticked, it'll be presented as prose text or HTML.

Marking tests

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[
  ["Correct y", 1, "y == [ a for a in x if a > 0.5]"]
]

A list of tests used to mark the student's answer.
Each item is a list with three values:

The name of the test, shown to the student above any feedback.
The proportion of the credit available for the part to award if this test is passed.
The code to run.

Validation tests

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[
  ["arithmetic works", "1+1 == 2"]
]

A list of tests used to validate that the student's code is acceptable.
Each item is a list with two string values:

A name which will be shown to the student if the test fails.
The code to run.

Variables to include in code

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dict()

Give a dictionary mapping variable names to their values. These variables will be available in the code that is run.

Advice

{code_block("y = [ a for a in x if a > 0.5]",["language":"python"])}

Note that you might expect len(y) to be somewhere around 50.

Give a worked solution to the whole question.

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Code
Code		Hasn't run yet

This question is used in the following exam:

Programming extension demo by Christian Lawson-Perfect in Programming extension.

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Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

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Checkpoint description

Christian Lawson-Perfect 1 year, 11 months ago

Chris Graham 3 years, 2 months ago

Error in variable testing condition

Parts

Code