QuickSort - 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 assistive comments available for observing the process of sorting. By clicking parts of the program code it is possible to get some explanation in natural language to Explanation window. The Help window offers advice about what the user can do with each clickable item in Algorithm window or "AIA: Quicksort window". The "AIA: Quicksort 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.

Evaluation

Colors are used to show the partitions, the sorted elements and the inactive 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 the 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. The biggest drawback with this tool is that the authors didn’t seem to be very familiar with GUI programming and in particular the widget set available for Java. Rather than using panes, each part of the tool ends up in its own window (possibly the cause of the stack dumps on the Mac). 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 RGB sliders 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

2006-11-07

Last Visited

2010-02-10

Last Updated

2000

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://math.hws.edu/TMCM/java/classes/xSortLab.jar

Edit

You may edit this entry if you have an account.

The Most Complex Machine - xSortLab - QuickSort

Recommendation

Recommended

Link

Delivery Method

Java Application

License

Non-OSI Open Source

Language

English

Author

David Eck

Institution

Hobart and William Smith Colleges

Project

xSortLab

Works

Yes

Description

Very intuitive visualization that explains the Quick Sort Algorithm. This can be used for classroom presentation, or individually by students.The method used here is a bar-swapping in a stepwise or continuous fashion with explanations of the code taking place. It is Instrumented for AlgorithmSimulation (compares and copies). It also has a separate simulation mode which dispenses with the swapping bars that makes the understanding easier and intuitive. Here the processing of each and every sublist in the whole array of numbers is sequential and separate, which enables easier understanding. It has log options that maintains the history of execution steps and a "Timed Sort" option that enables the user to define his array set and compare the time complexities of quick sort with other sorting schemes.

Evaluation

This is a good visualization for Quicksort. It is highly intuitive with different colors being used to indicate which element is in its sorted position and a green rectangle highlights the area of the list that is currently under consideration. The Pivot moves out of the array to clearly indicate that it is something different is happening. A red outline it then used to indicate which item is currently being compared to the pivot. There is a step by step explanation at the bottom. The visualization is missing some key functionalities like user control of the data to sort, viewing execution history and flexible execution control. It does not have a pseudocode window. Most importantly, it does not directly show how the array is broken into sub-arrays (though it almost gets that idea across by boxing the part of the array currently being processed). Even though the visualization misses those features, it effectively gives an idea about how Quicksort works, how it handles each partition, and how it iterates through by effectively visualizing partitions, providing text messages explaining each step of the execution flow.

Animation; Step Control; Canned Data

Teaching the Concept; Self Study; Lecture Aid

Screenshots

Videos

References

An applet at the project homepage. Simply select the desired sorting algorithm. Then press "go" for a running animation, or "step" to control it step by step. If it goes too slowly for you, click the "fast" checkbox.

First Visited

2006-09-06

Last Visited

2010-02-11

Last Updated

1997-08-01

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://pages.stern.nyu.edu/~panos/java/Quicksort/index.html

Edit

You may edit this entry if you have an account.

Interactive Quicksort

Recommendation

Recommended

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Ipirotis Panayotis

Institution

University of Patras

Project

Works

Yes

Description

Random and user-defined data sets. Stepwise operation. Explanations of what is taking place. Note: There is also a copy of this applet posted at: http://www.eecs.wsu.edu/~holder/courses/cse2320/lectures/applets/quicksort/

Evaluation

Thorough explanations and user-defined data sets make this recommended. The only major item lacking is a visual display of how the array has been decomposed into partitions.

Random Data; User Data; Step Control

Teaching the Concept

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2009-04-28

Last Updated

1998-06-09

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

JHAVÉ - Quick Sort

Recommendation

Recommended

Link

Delivery Method

Java Web Start

License

CreativeCommons

Language

English

Author

Myles McNally

Institution

Alma College

Project

JHAVÉ

Works

Yes

Description

Visualization for Quick Sort. Includes dynamically highlighted pseudo code. Users can select random data, or give their own data. As the presentation progresses, the sub-array processing is shown as branches of a virtual tree.

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 an exceptionally clear presentation of Quick Sort. The presentation mechanism for showing the subarray processing is effective. 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. There are probably too many "states" being displayed, since each line of pseudocode gets its own slide. This can be a bit tedious. Some pruning of some of the states might help, but this is probably difficult since the slide show gets generated from the data input.

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 this AV. Some Jhave AVs include a tutorial on how the AV itself or the underlying algorithm works. At the bottom are links to the AV (you can run 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 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 or short-answer question to answer.

First Visited

2008-07-08

Last Visited

2008-07-10

Last Updated

2008-07-01

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.cs.hut.fi/Research/TRAKLA2/exercises/RecursiveQuicksort.html

Edit

You may edit this entry if you have an account.

Trakla - Quicksort

Recommendation

Has Potential

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 demonstrating proficiency at determining bounds of the subarrays that are called in the Quicksort recursion stack. During the process, the user will have sorted the elements. Pseudocode is provided.

Evaluation

The idea of having students demonstrate proficiency actively is good. But this implementation does not work well for two reasons. First, the instructions are extremely cryptic, and it takes far too much effort to figure out the mechanics for how to satisfy the exercise. Once that hurdle is overcome, it can get rather tedious to go through all of this, though that part might not be too bad if so much effort hadn't been expended already in figuring out what you are supposed to do. A bigger problem is that the exercise is focusing on mechanics a great deal. Its not clear how well this gets the concepts of Quicksort across. In any case, this AV does not stand on its own, instructors will need to supplement it with a lecture or textbook.

Canned Data; Predictions

Lecture Aid; Self Study; Lab Exercise

Screenshots

Videos

References

First Visited

2008-07-26

Last Visited

2008-07-26

Last Updated

2006-01-25

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.cs.auckland.ac.nz/software/AlgAnim/alg_anim.html

Edit

You may edit this entry if you have an account.

Auckland - QuickSort Animation

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Woi Ang; John Morris

Institution

University of Auckland

Project

Morris' Collection

Works

Yes

Description

There are actually two Quicksort AVs at this site. We focus on the one authored by Woi Ang, since the other one is relatively weak. This AV can run in step or animation mode. It shows which sub array is currently being partitioned.

Evaluation

Good, clean AV. No pseudocode or step-by-step explanation of the process, and no hierarchical breakdown of the partitioning process.

Step Control; Animation; Canned Data

Lecture Aid; Self Study

Screenshots

Videos

References

First Visited

2006-11-06

Last Visited

2008-07-17

Last Updated

1998

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.csanimated.com/animation.php?t=Quicksort

Edit

You may edit this entry if you have an account.

CS Animated - Quicksort

Recommendation

Has Potential

Link

Delivery Method

Flash

License

Non-Commercial

Language

English

Author

Bill Jacobs

Institution

None

Project

Jacobs' AV Lectures

Works

Yes

Description

Entroduction to quicksort. A multimedia lecture, with audio used to explain the data structure and a series of slides for the visual component. Each slide has its own video component, so it is easy to move through the lecture. Each slide has flash animation as appropriate.

Evaluation

Good intro overview to the algorithm, though some details are missing. Not interactive, but in that sense it is certainly no worse than a standard animation. The presentations are clear.

Animation Only; Canned Data

Self Study

Screenshots

Videos

References

First Visited

2008-06-23

Last Visited

2008-06-23

Last Updated

2008-06-01

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.cs.hope.edu/~dershem/ccaa/animator/Animator.html

Edit

You may edit this entry if you have an account.

The Animator - Quicksort

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Peter Brummund

Institution

Hope College

Project

Animator

Works

Yes

Description

Traditional swapping-bars animation with user-selectable colors, number of blocks, a few data set choices(random, ascending, descending), speed control(but no step-through), and AlgorithmSimulation-type readouts for number of swaps and number of compares. Also has bounce-along Java code.

Evaluation

This is an OK visualization if all you need is an animation and are already familiar with QuickSort. There is support for showing what subset of the array is being worked on, a feature not commonly found. It shows the number of comparison and number of swap required, which can help in performance comparison with other algorithms. However, most of the features are cosmetic in nature and do not add much value. The pseudo code is in C, which users may not be familiar with. No rewind-playback option, need to start from the beginning. Does not guide the user to explore corner cases. Does not provide any explanation of the algorithm. No option for user input.

Comparison

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2006-11-07

Last Updated

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

Sorting Demo - Quicksort

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

Works

Yes

Description

This tool allows users to enter their own data set and it is a good start to understand how an algorithm works by examining different data sets for a user. The user interface is not intuitive, but not hard to figure out after some trials. It provides multiple views as pseudo code and the visualization. It also includes speed control, and AlgorithmSimulation instrumentation (comparisons, exchanges), but it lacks stepwise operation.

Evaluation

This visualization provides multiple views as pseudo code and the visualization. It visualizes partitions by putting i and j values of the pseudo code on the correct places of the array. This is an important feature since it gives users to have an idea about which partition is being worked on, how the algorithm handles that part and how the algorithm iterates on the data set. It also provides information about how the current pivot value is selected, which is also important in understanding how the algorithm will iterate. It can be a good start for a user who wants to understand how the algorithm is represented on a pseudo code and how each line in the pseudo code works on a given array. Despite its useful features such as multiple views, custom input data sets and performance information indicated by number of comparisons and exchanges; the tool misses some key functionalities like providing the ability to go back during run time and stepwise movement ability. Being able to see the execution history, and being able to run the visualization backwards are also important key features which might be used to explain how the algorithm divides arrays into partitions and how it combines them. These features should be included in a quick sorting algorithm visualization.

Teaching the Concept; Debugging; Exploring the Concept

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2008-02-11

Last Updated

2000

Topic

Community

Average rating:	2.0
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

Data Structures Navigator - Quicksort

Recommendation

Recommended

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

This java application visualizes quick sort amongst several other sorting algorithms. It does not permit user input, instead has a canned data set. It sorts letters and not numbers. The active elements (elements being compared) are highlighted by blue so as to differentiate from the inactive elements which are cream. It lets the users choose the operations to visualize namely, Divide, sort, swap, unsort and reverse. It provides the option of viewing as a continuous animation or a step wise animation controlled by the user. At any point of time, the user can prefer to move on to the end of the visualization by clicking on the complete button. The screen has a right bottom pane displaying the history of operations (not to be confused with the history of states). After each divide, the sub lists are separated and shown as a tree structure. The pivot variable is displayed on the top left corner at every stage to help the user stay in context. The tool uses one of the more complex pivot choosing algorithms (middle of three). It provides a help feature.

Evaluation

The visualization is fairly intuitive. It does a fair job in explaining the working of the algorithm. The visualization shows quick sort in a hierarchical structure that makes explicit the recursion over sub arrays. This hierarchical presentation is what makes this AV "Recommended". The visualization has user interaction. Once started, the visualization is merely an animation (either continuous or step controlled). The visualization replaces the array with a node labeled with the pivot of that stage in the hierarchical structure. This takes away contextual information and makes it hard for the user to look at past states. The tool uses one of the more complex pivot choosing algorithms (middle of three). This would be a reasonable choice if there was any explanation, but there isn’t. - it frequently swaps two values even when they are identical. Another issue with this tool is that it appears to have just two data sets - one integer and one string (though I was not able to enable the integer set). The string can be randomly scrambled or reversed, though for some reason the authors animated these sequences (there is an option to turn this off, but it is on by default). There appears to be a text entry field, but it seems to be disabled. The user can determine the speed of animations. But the option to control the animation speed is hidden somewhere inside the menu, while a large amount of screen real estate is taken up by a little collection of check boxes that control which aspects of the algorithm are animated. Another large portion of the window is taken up with the “history” panel. Unfortunately, this is just a hierarchical list of items that say “sort”, “swap” or “divide”.

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

Average rating:	4.0
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

Data Structure Visualization - Comparison Sorts - Quick 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

Part of DSV integrated visualization suite. Swapping-bars paradigm with speed control and stepwise operation. Only random data sets.

Evaluation

This quick sort visualization uses bar-swapping paradigm. The user can step through the visualization or run it as an animation, with a slider used to control the speed. The visualization also adds actual values for the bars and array indices. Couple of strong points of this AV includes 1) data not under consideration is grayed out, and 2) the items being compared are highlighted. In particular the red line that is drawn across the bars at the height of the pivot makes the result of the comparisons very clear. However the visualization is not enough as a standalone explanation for quick sort algorithm. There is no code associated with the visualization. Especially this AV is lacking in explanation how partitioning works. It’s really hard to distinguish pivot from other bars; some sort of color distinction would help. There might be some confusion as to how to reset and restart the presentation. This tool could possibly be used as a teaching aid to visualize an explanation, but it’s not recommended as an independent learning tool. Also it really needs to be accompanied by some explanation.

Animation; Step Control; Random Data

Lecture Aid

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2008-07-01

Last Updated

2006-04-05

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://olli.informatik.uni-oldenburg.de/fpsort/QuickAnimation.html

Edit

You may edit this entry if you have an account.

Quicksort-Animation

Recommendation

Has Potential

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Andreea Barbu

Institution

University of Oldenburg

Project

Works

Description

Has bounce-along pseudocode in 4 languages. Has stepwise and continuous operation. Entirely in German. Bar-swapping and possible AlgorithmSimulation outputs (but I cannot determine because I don't speak German).

Evaluation

Might be a 'recommended' except for the language problem.

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2007-04-05

Last Updated

2001-01-31

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

Interactive Data Structure Visualization - Efficent Sorts (Quick 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

Bar-swapping with speed control animation or step-through control. Also has an "I'll Try" mode where viewers are asked to select what bars will be swapped.

Evaluation

The bar-swapping presentation is reasonable, but this could have been done better to be clearer about the sub-array being processed. What makes this AV stand out is the "I'll Try" mode. Here, the user must demonstrate understanding about how the algorithm works by choosing the values to swap. The only flaw is that there is no pseudocode or other explanation of the algorithm, so the user has to come to this exercise with some other source of information about the algorithm.

Random Data; Step Control; Animation; Predictions

Lecture Aid; Self Study; Lab Exercise

Screenshots

Videos

References

First Visited

2007-04-05

Last Visited

2008-07-15

Last Updated

2005-12-03

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

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

Edit

You may edit this entry if you have an account.

Ghosh - Quick 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

Works

Yes

Description

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

Evaluation

Despite the garish color scheme, Quicksort II could be a good visualization with some changes. 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) makes this presentation painfully 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.

Lecture Aid

Screenshots

Videos

References

First Visited

2006-11-06

Last Visited

2008-07-15

Last Updated

2001-08-12

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://homepages.dcc.ufmg.br/~dorgival/applets/SortingPoints/SortingPoints.html

Edit

You may edit this entry if you have an account.

Animation of Sorting Algorithms

Recommendation

Not Recommended

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Dorgival Olavo Guedes Neto

Institution

Universidade Federal de Minas Gerais

Project

Works

Yes

Description

No explanation of what is taking place. Another bar-swapping animation (although the "bars" are dots at different heights). Speed control.

Evaluation

Even the slowest speed is too fast to understand what's going on.

Animation

Comparison

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2007-04-05

Last Updated

1998-02-01

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.cs.princeton.edu/courses/archive/spr09/cos226/demo/ah/QuickSort.html

Edit

You may edit this entry if you have an account.

Gawain Quicksort

Recommendation

Not Recommended

Link

Delivery Method

Java Applet

License

BSD-like

Language

English

Author

Alejo Hausner

Institution

Princeton University

Project

Gawain

Works

Yes

Description

The page shows three AVs to illustrate quicksort. The first is a standard bar display. The partitions being processed are not well delimited, so one really only sees some bars being swapped around. The second AV shows what happens to a sorted list. The third shows a dot array as another view of what is happening.

Evaluation

This visualizations are fairly incomprehensible. They give an impression for how different parts of the file are processed, but it do a poor job of explaining to a student how Quicksort operates. Not sure how this would even be useful to an instructor during a lecture.

Animation

Nothing

Screenshots

Videos

References

The link is to a page containing three applets. The limited controls should be fairly clear.

First Visited

2006-11-07

Last Visited

2009-08-17

Last Updated

1999-05-09

Topic

Community

Average rating:	4.0
Your rating:	You must be logged in to Rate.

http://lecture.ecc.u-tokyo.ac.jp/~yamaguch/pub/cp1-7/quickSortV.html

Edit

You may edit this entry if you have an account.

Quick Sort Visualization (Fast)

Recommendation

Not Recommended

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

Kazunori Yamaguchi

Institution

University of Tokyo

Project

Works

Description

Does not work.

Evaluation

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2007-04-05

Last Updated

2006-01-18

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://grail.sourceforge.net/demo/quicksort/quicksort.html

Edit

You may edit this entry if you have an account.

Quicksort Visualization

Recommendation

Not Recommended

Link

Delivery Method

Python

License

Non-OSI Open Source

Language

English

Author

Institution

Corporation for National Research Initiatives

Project

Works

Description

Requires an ancient experimental browser called GRAIL.

Evaluation

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2007-04-05

Last Updated

1996-04-10

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://www.cosc.canterbury.ac.nz/people/mukundan/dsal/QSort.html

Edit

You may edit this entry if you have an account.

Java Applets Centre - Quick Sort

Recommendation

Not Recommended

Link

Delivery Method

Java Applet

License

Unavailable

Language

English

Author

R. Mukundan

Institution

University of Canterbury

Project

Java Applets Centre

Works

Yes

Description

This is a simplistic bar-swapping visualization with only continuous mode operation. The user cannot step through the visualization at his own pace or control the animation speed. The data set is randomly generated based on a user defined size. The visualization steps through the quicksort algorithm when the input size lies in the range 5-20. Beyond an input size of 20, the visualization operates in a "fast mode" (i.e. moves the bars around very quickly). It shows counts for swaps and compares.

Evaluation

Overall, this is a disappointing visualization. The lack of speed control or stepwise operation is a major flaw. The granularity of the animation is too coarse. The pivot pops up in the right position and the sub array is rearranged in a single step.There is no explanation for what the algorithm is doing in any given step, what bars are being compared, or how the partition function works. The visualization does not clearly illustrate the divide and conquer strategy. The color scheme is distracting and does not provide any visual cues that could aid learning. The execution history is not maintained, which makes it extremely hard to keep track of what is going on. The "fast mode" is not useful for learning the algorithm. It is extremely hard to grasp the quicksort algorithm from this visualization.

Animation Only; Random Data

Lecture Aid

Screenshots

Videos

References

First Visited

2006-11-07

Last Visited

2008-02-16

Last Updated

2006

Topic

Community

Average rating:	2.0
Your rating:	You must be logged in to Rate.

http://www.animal.ahrgr.de/showAnimationDetails.php3?anim=46; http://www.animal.ahrgr.de/showAnimationDetails.php3?anim=100

Edit

You may edit this entry if you have an account.

Animal - Quick Sort

Recommendation

Not Recommended

Link

Delivery Method

Animal Animation

License

Non-Commercial

Language

English; German

Author

Jens Brodowski

Institution

TU Darmstadt, Darmstadt, Germany

Project

Animal

Works

Yes

Description

Presents a slideshow walking through an example of Quick Sort. Pseudocode follows along with the prsentation, and an array shows values (letters) and two index pointers. A second version of the presentation is available that focusses on the divide-and-conquer aspects of the algorithm.

Evaluation

Not very compelling, compared to many other alternatives. As the animation progresses, the left and right bounds indexes move under an array, and the pseudocode changes color to show the corresponding step. Not particularly intuitive, no clear sense of the array being broken into subarrays.

Animation; Step Control; Canned Data

Lecture Aid

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

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://alvie.algoritmica.org/

Edit

You may edit this entry if you have an account.

ALVIE - Quicksort

Recommendation

Unrated

Link

Delivery Method

Java Application

License

By Request

Language

English

Author

Pilu Crescenzi

Institution

University of Florence

Project

ALVIE

Works

Yes

Description

Walkthrough showing the Quicksort algorithm.

Evaluation

Simple-to-use user interface for walking through the example. Simply open up the AV (see directions below) and step through the example with pseudo-code. As you go through the example, you are directed to the corresponding line in the pseudocode and given a line or two of explanation in the message window. Attractive layout of the data, including colors.

Step Control; Canned Data

http://sites.google.com/site/alviehomepage/alvie3/downoads/quicksort.swf

Lecture Aid; Self Study

Screenshots

Videos

References

Download and unzip the ALVIE system from the website. Double click on the .jar file. Within the ALVIE pane (not the GRIND pane), click on the "eye" icon (third icon from the left in the toolbar) to get a list of algorithms from which select the AV that you want. Once selected, click OK and step through the AV with the arrow icons.

First Visited

2010-01-29

Last Visited

2010-01-29

Last Updated

2009-12-20

Topic

Community

Average rating:	unrated
Your rating:	You must be logged in to Rate.

http://olli.informatik.uni-oldenburg.de/fpsort/QuickAnimation.html; http://olli.informatik.uni-oldenburg.de/fpsort/index.html

Edit

You may edit this entry if you have an account.

OLLI - Quicksort

Recommendation

Not Recommended

Link

Delivery Method

Java Applet

License

Language

German

Author

Andreea Barbu; Marcus Dromowicz; Xia Gao; Matthias Koester; Christian Wolf

Institution

University of Oldenburg

Project

OLLI

Works

Yes

Description

The first link is to the Quicksort applet, that is part of a larger tutorial on Quicksort and bubblesort.

Evaluation

Since I can't read German, I can't evaluate the quality of the tutorial, nor explain why these two particular algorithms are juxtaposed. However, the Quicksort applet itself, while visually quite appealing, is poor pedagogically. The example is tiny (5 values). The index graphics are hard to comprehend. There is poor sense of the array being broken into subarrays. This is a canned animation, with no user interaction.

Canned Data; Animation

Lecture Aid

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

2010-02-08

Last Visited

2010-02-08

Last Updated

2001-02-01

Topic