HeapSort - Algoviz Wiki

Works

Yes

Description

The application works well and shows nice, intuitive visualizations. The application launches four different windows that can be a positive or negative thing. It may make it easy to handle each window separately or alternatively it can cause difficulties for overall attention. There are Explanation window, Algorithm window (showing program code), "AIA: Quicksort window" (for showing animation) and Help window. The general impression about user interface is good. In the Algorithm window the user can see the program code either in real program code mode or in natural language mode. It is beneficial to have lot of comments available for observing the process. By clicking parts of the program code it is possible to get some explanation in natural language to Explanation window. Parts of pseudocode can be opened or closed, which changes the stepsize of the visualization. The Help window offers advice about what the user can do with each clickable item in Algorithm window or "AIA: Heapsort window". The "AIA: Heapsort window" shows a set of randomized numbers and right above them vertical bars with varying length that corresponds to the size of each number. In the windows there are also buttons with names Step, Back, Run, Pause and Reset, as well as set of menu controls for fine-tuning. The basic functionality is based on seeing first the vertical bars in a randomized order and step by step the algorithm will arrange the bars into ascending or descending order. Both the tree view and the array view are shown.

Evaluation

Colors are used to show the status of elements. They clearly show the pivot and the partition boundaries and the top and bottom values (unfortunately, these are labeled with the uninformative i and j). It also builds a hierarchy in a second sub-visualization that shows each sub array as it is being sorted, giving a nice picture of how the array is being divided up. For animation control, there is a speed control as well as pause, step and back buttons. There are a number of options for data – random, sorted, reverse sorted, all equal and user entered. A very nice feature is the ability to pick different pivot choosing algorithms (right, random, middle of three random and middle of three). Unfortunately, the overview doesn’t explain this as well as it could. The source code display shows fully commented source code for the algorithm. Unfortunately, this proves less useful when the visualization is actually running. A nice feature is that the code is instrumented to be foldable - replacing a collection of steps (like a swap) with a high level piece of pseudocode. Even better, this affects to visualization - when steps have been abstracted away they happen atomically in the visualization. The quiz is less useful. It can’t be used in conjunction with the visualization and mostly asks questions that can be answered (or perhaps even have to be answered) as the result of memorizing some of the overview explanation rather than as a result of working with the visualization. Also, while it provides feedback after each question, it doesn’t give any sort of final assessment of the overall score. There are some inconveniences with the way that the interface is broken into separate window, which may stem from the lack of Java tools available when this applet was originally written. Rather than using panes, each part of the tool ends up in its own window. This is cluttered and hard to manage. Things like the explanation window are easy to lose or overlook. The code folding is implemented with what looks like an abused file browser as each abstract line is decorated with a folder icon. The tool for changing the highlight color consists of three tiny custom RGBsliders and the custom data entry pane has to been seen to be believed. In addition, there seems to be a bug in the quiz code. There are actually three “modes”: the normal one, one called “self test” and the quiz. When I tried “self test” the only thing that seemed to happen is that the overview window was hidden. Even odder, when I went to the quiz mode, the overview came back (particularly startling as the answers to most of the questions were in that window).

Animation; Step Control; Canned Data; Random Data

Lecture Aid; Self Study

Screenshots

Videos

References

The link above takes you to the AIA demonstration index page. Click on the link to the desired AV, and it should load in your browser as a multi-paned Java applet. Note that the level of detail shown in the visualization is directly tied to the level of detail that you choose to expose in the pseudocode pane.

First Visited

2008-07-02

Last Visited

2010-02-10

Last Updated

2000

Topic

Community

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http://jhave.org/learner/sorts/HeapSort.php

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JHAVÉ - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Java Web Start

License

CreativeCommons

Language

English

Author

Myles McNally

Institution

Alma College

Project

JHAVÉ

Works

Yes

Description

Visualization for Heap Sort. Includes dynamically highlighted pseudo code. Users can select random data, or give their own data.

Evaluation

The AV is set up as a series of "slides" in one pane, and pseudocode in the adjacent pane. As the user steps through the "slides", the associated pseudocode is highlighted. Occasional questions pop up for the user to answer. This is a very clear presentation of Heap Sort, showing both the array and the tree structure. The AV is supported by an HTML page that shows complete pseudocode and gives some guidance on using the AV, though the guide questions are not so extensive as for some other JHAVÉ topics.

Step Control; Questions; Random Data; User Data

Lecture Aid; Self Study; Lab Exercise

Screenshots

Videos

References

Clicking on the link above will take you to a login page for Jhave. If you do not want to create an account at jhave.org, use anonymous@anonymous.com as your user name and anonymous as your password when you are asked to login. You will then be taken to the Jhave page for Heapsort. Most of this is a tutorial on how Heapsort works. At the bottom are links to the AV itself (you can do it with a built-in quiz system on or off). The first time you try to run any Jhave exercise, you will have to download the Jhave webstart application. This should happen automatically when you click the link. (You might need to install Java WebStart if it is not on your machine.) Once you download the Jhave application, the Heapsort AV should start automatically. You can then step through the AV by repeatedly clicking the right arrow button. Occasionally, you will be given a multiple-choice question to answer.

First Visited

2008-07-08

Last Visited

2008-07-08

Last Updated

2008-07-01

Topic

Community

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http://www.animal.ahrgr.de/showAnimationDetails.php3?anim=30; http://www.animal.ahrgr.de/showAnimationDetails.php3?anim=79

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Animal - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Animal Animation

License

Non-Commercial

Language

English; German

Author

Marc-Daniel Haunschild

Institution

TU Darmstadt, Darmstadt, Germany

Project

Animal

Works

Yes

Description

Presents a slideshow walking through an example of heapsort. Includes pseudocode tied to the presentation and duel views of the array and tree representations.

Evaluation

Good, clear presentation. Animation for swaps is well done, you see the swap without it being a tedious, slow nuisance. The major deficiency of this presentation is that it needs some explanation as the visualization is progressing of the idea that the heap is first built, and then unloaded.

Animation; Step Control; Canned Data

Lecture Aid; Self Study

Screenshots

Videos

References

For detailed instructions on how to install Animal and run Animal AVs, see: http://www.algoanim.info/Animal2/?q=node/290. Once you have installed the Animal .jar file and downloaded/unpacked the .zip file of Animal animations, you are now ready to run Animal. Run the .jar file to start Animal. Then go to the "Open" menu item, and browse to where you put the animal animations you got in the .zip file. Pick this AV from the list. You can then step through the animation, or use "kiosk mode" to have the steps fed to you at a constant pace.

First Visited

2007-07-21

Last Visited

2010-02-05

Last Updated

1999-05-11

Topic

Community

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http://www.brian-borowski.com/Sorting/

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Sorting Demo - Heapsort

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unlicensed Sourcecode

Language

English

Author

Brian S. Borowski

Institution

Seton Hall University

Project

Borowski's Collection

PartOfCollection

Works

Yes

Description

Includes bounce-along pseudocode, user-defined and built-in datasets, speed control, and AlgorithmSimulation instrumentation (comparisons, exchanges). No stepwise operation.

Evaluation

Cluttered UI and lack of stepwise operation keep this out of the "recommended" list, but it's not a bad start.

Teaching the Concept; Debugging

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2007-04-05

Last Updated

2000

Topic

Community

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http://www.cs.duke.edu/courses/cps100/fall02/lects/oct24/heap1.html

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JAWAA - Heap build and Heapsort Tutorial

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Non-OSI Open Source

Language

English

Author

Susan Rodger

Institution

Duke University

Project

JAWAA

Works

Yes

Description

A set of coursenotes with an AV for building a heap and removing the items (heapsort). Continuous operation animation.

Evaluation

The tutorial is quite helpful (though for web use, it would be better if it were reformatted onto one page). The AV is pure animation. With stepwise operation and improved step-by-step text to explain what is happening as the AV progresses, this would be "recommended".

Animation Only; Canned Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-11-08

Last Visited

2008-07-23

Last Updated

2002

Topic

Community

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http://dbs.mathematik.uni-marburg.de/research/projects/dsn/

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Data Structures Navigator - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Java Application

License

Unavailable

Language

English

Author

Jens-Peter Dittrich; Jochen van den Bercken; Tobias Schäfer; Marcus Klein

Institution

Phillips-University of Marburg

Project

Data Structure Navigator

Works

Yes

Description

Shows both the array and the tree representation, and shows the values being swapped in both. Stepwise/continuous operation with speed control, swaps blocks containing letters. Gives options about which steps to visualize. Shows history of operations. Multiple built-in data sets. Shows heap structure and physical implementation.

Evaluation

Fairly clear and straightforward presentation for heap sort. No pseudocode or explanation for what is happening.

Step Control; Animation; Canned Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-09-01

Last Visited

2008-07-16

Last Updated

2000-07-31

Topic

Community

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http://www.cs.usfca.edu/galles/visualization/download.html

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Data Structure Visualization - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Java Application

License

Unlicensed Sourcecode

Language

English

Author

David Galles

Institution

University of San Francisco

Project

Data Structure Visualization

Works

Yes

Description

Shows both array and heap view, shows swaps. Animation (with speed control for the overall pacing) and step control.

Evaluation

A decent stab at a heapsort visualization, but some explanation of the steps would go a long way towards making this recommended. Very helpful that it also shows the logical view of the heap long with the array view. The interface is a bit tricky to figure out how to get it into step mode (as opposed to straight animation).

Animation; Step Control; Random Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-11-08

Last Visited

2008-07-02

Last Updated

2006-04-05

Topic

Community

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http://research.cs.vt.edu/AVresearch/HeapSort

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Virginia Tech - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

GPL

Language

English

Author

Purvi Saraiya; Cliff Shaffer

Institution

Virginia Tech

Project

Virginia Tech Algorithm Visualizations

PartOfCollection

Works

Yes

Description

Shows physical and logical structure of heap. Has pseudocode (two options). Allows user-entered data sets. Loads in a separate window; this needs to be fixed.

Evaluation

Good presentation of Heap Sort.

Step Control; User Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-11-08

Last Visited

2007-04-10

Last Updated

2002-07-01

Topic

Community

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http://research.cs.vt.edu/AVresearch/Swan/

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Swan - Heapsort

Recommendation

Has Potential

Link

Delivery Method

Windows Application

License

GPL

Language

English

Author

Jun Yang; Cliff Shaffer

Institution

Virginia Tech

Project

Swan

Works

Yes

Description

Part of the Swan distribution. User selects an array size, and then is taken step by step through the process of heapsort. Simultaneous view of the array and the tree representations with color coding for the nodes being processed.

Evaluation

Generally clear presentation. Showing step by step what happens is good, but it would be better if there were a panel showing a series of messages rather than only showing the current action. Users cannot enter their own data values. They select an array size and then random values are generated.

Step Control; Random Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-11-08

Last Visited

2008-06-27

Last Updated

1996

Topic

Community

Average rating:	unrated
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http://www.cse.iitk.ac.in/users/dsrkg/cs210/html/sortingpage.html

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Ghosh - Heap Sort

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

R. K. Ghosh

Institution

Indian Institute of Technology, Kanpur

Project

Ghosh's Collection

PartOfCollection

Works

Yes

Description

Two heapsort AVs available -- use Heapsort II, since Heapsort I is just a simple bar-swapping presentation. Heapsort II has stepwise operation, informational messages describe what is happening. Random data of chosen size.

Evaluation

Despite the garish color scheme, this is almost a good visualization. The explanations for what is going on are fairly clear, with a step-by-step progression under user control. The problems are that the animation speed (each step is a mini-animation) is too slow, without any speed control, and the message about what is actually happening gets clobbered at the end of the step. So while the user can control the step progression, within the step there is no sense of control.

Step Control; Animation; Random Data

Lecture Aid

Screenshots

Videos

References

First Visited

2006-11-06

Last Visited

2008-07-15

Last Updated

2001-08-12

Topic

Community

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http://nova.umuc.edu/~jarc/idsv

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Interactive Data Structure Visualization - Heap Sort

Recommendation

Recommended

Link

Delivery Method

Java Applet

License

By Request

Language

English

Author

Duane J. Jarc

Institution

University of Maryland University College

Project

IDSV

Works

Yes

Description

Shows heap, has speed control. Also has an "I'll Try" mode where viewers are asked to select what bars will be swapped. There is an explanation page to go along with the exercise to guide the user.

Evaluation

The "I'll Try" mode makes the user demonstrate understanding. It might help if there were pseudocode, but otherwise this is excellent teaching aid.

Lecture Aid; Self Study; Lab Exercise

Screenshots

Videos

References

First Visited

2007-04-10

Last Visited

2008-07-15

Last Updated

2005-12-03

Topic

Community

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http://www2.hawaii.edu/~copley/665/HSApplet.html

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Heap sort visualization

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unlicensed Sourcecode

Language

English

Author

Mike Copley

Institution

University of Hawaii

Project

StandAlone

StandAlone

Works

Yes

Description

Includes bounce-along pseudocode, allows user-entered data sets, animation with no speed control or other interactivity, extensive user's manual

Evaluation

The lack of speed control or step-by-step operation drops this visualization out of the "recommended" category; otherwise it's not bad.

Debugging

Screenshots

Videos

References

First Visited

2007-03-29

Last Visited

2007-03-29

Last Updated

1997-05-07

Topic

Community

Average rating:	unrated
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http://www.cs.hut.fi/Research/TRAKLA2/exercises/HeapSort.html

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Trakla - Heap Sort

Recommendation

Not Recommended

Link

Delivery Method

Java Application

License

GPL

Language

English

Author

Ville Karavirta; Ari Korhonen; Lauri Malmi; Kimmo Stålnacke

Institution

Helsinki University of Technology

Project

Trakla2

Works

Yes

Description

User works through an exercise of swapping elements within the heap to demonstrate proficiency at the mechanics of mergesort.

Evaluation

As an exercise, this is too tedious, and the directions are unclear. Stepping through the "model answer" provides no understanding of how the algorithm works because the granularity is to large (one step per max element removed), such that the user can't recognize what changed in the heap at each step.

Canned Data; Predictions

Lecture Aid; Self Study; Lab Exercise

Screenshots

Videos

References

First Visited

2008-07-29

Last Visited

2008-07-29

Last Updated

2006-01-25

Topic

Community

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http://olli.informatik.uni-oldenburg.de/heapsort_SALA/deutsch/inhalt.html; http://olli.informatik.uni-oldenburg.de/heapsort_SALA/english/start.html

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OLLI - HeapSort

Recommendation

Unrated

Link

Delivery Method

Java Applet

License

Language

German; English

Author

Nils Faltin; Tobias Gross

Institution

University of Oldenburg

Project

OLLI

Works

Yes

Description

A complete tutorial for heapsort with a series of embedded applets. Users must interact with the applets to move the action forward.

Evaluation

The presentation is fairly detailed. This tutorial can stand alone as an introduction to heapsort.

Step Control; Canned Data; Questions

Lecture Aid; Lab Exercise; Self Study

Screenshots

Videos

References

Clicking on the link above will take you to a "table of contents" for the heapsort tutorial. You can click on sections, or you can follow the forward/backward arrows to go through the tutorial.

First Visited

2010-02-06

Last Visited

2010-02-06

Last Updated

2002-04-01

Topic