Problem 303. Convert Hard Drive marketing sizes to actual data sizes

Created by Alan Chalker

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Hard drive sizes are typically marketed using the decimal meaning of prefixes, whereas RAM uses binary meanings. For example:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>A 10 GB hard drive (common only a few years ago) typically has 10,000,000,000 bytes 10 GB of RAM though is equal to 10,737,418,240 bytes</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>More information about this can be found</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"http://en.wikipedia.org/wiki/Hard_disk_drive#Units_of_storage_capacity\"><w:r><w:t>here.</w:t></w:r></w:hyperlink></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The problem is to take 2 inputs based upon decimal prefixes (a number representing size and a string representing the units) and output the equivalent size using binary prefixes, as seen below:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[[100], 'MB' -> [95.4]\n[100], 'GB' -> [93.1]]]></w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

304 Solutions
66 Solvers

Last Solution submitted on Oct 19, 2022

Last 200 Solutions

Problem Comments

4 Comments

4 Comments

Show 1 older comment

@bmtran (Bryant Tran) on 10 Feb 2012

could you provide some sort of indication as to the precision of said number?

Gunther S on 14 Feb 2012

please fix the errors in the solution check, or at least use consistent precision :/

David Verrelli on 25 Dec 2017

My calculation suggests test 3 should have an answer of approximately 465.661, which is tricky to round to 465.5. (Not impossible, but not obvious/intuitive, and not consistent with answers specified for the other tests.) . . . Why was it like this? My guess is that all three answers were adapted directly from the three rows in the contemporary WP article linked to in the problem statement ( https://en.wikipedia.org/w/index.php?title=Hard_disk_drive&oldid=476051941#Units_of_storage_capacity ), to wit: * 100MB = first row; * 10GB = one tenth of second row; * 500GB = half of last row. This yields the peculiar rounding found in the Test Suite.

Rafael S.T. Vieira on 17 Aug 2020

This problem is not correct at all. Test suite values were probably copied from Windows or somewhere in which they've rounded up the requested factor to 3 decimals. And even worse, sometimes this had been twice (at the factor, and after multiplying it by the alledged value).

Solution Comments

Solution 119671

2 Comments

2 Comments

Jean-Marie Sainthillier on 27 Jul 2012

Sorry but I don't understand your rounding results.

Rafael S.T. Vieira on 17 Aug 2020

You were going at the right direction. The issue is that the author probably copied a rounded value from somewhere.

Solution 36013

2 Comments

2 Comments

@bmtran (Bryant Tran) on 10 Feb 2012

I would consider this to be the best solution, though it fails the test cases (only because of the precision of the test suite answers).

Rafael S.T. Vieira on 17 Aug 2020

Actually, this solution is creative, but wrong, even without the rounding issues. The needed factor is found by finding the difference between the decimal and the binary representation.

Problem Recent Solvers66

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 303. Convert Hard Drive marketing sizes to actual data sizes

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers66

Suggested Problems

More from this Author39

Problem Tags

Community Treasure Hunt

Problem 303. Convert Hard Drive marketing sizes to actual data sizes

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers66

Suggested Problems

More from this Author39

Problem Tags

Community Treasure Hunt

Players