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For Teachers


Software Requirements


Android iOS Windows MacOS
with best with Chrome Chrome Chrome Chrome
support full-screen? Yes. Chrome/Opera No. Firefox/ Samsung Internet Not yet Yes Yes
cannot work on some mobile browser that don't understand JavaScript such as.....
cannot work on Internet Explorer 9 and below




end faq







Creating an Interactive Electronic Textbook 


Course Description

Org Agency


Classes Available(Please Click on a Date)

Max Class Size

Course/ Class Fee


Basic how-to and explore the Easy Java/JavaScript Simulations (EjsS) modeling and authoring tool. Create brand new simple mathematical and physics computational model remix existing models in the digital libraries, especially the Singapore Library. create or remix one model based from an existing example in the library export 1 to 2 existing model with supporting text into an epub file as an electronic interactive textbook-chapter.
Preferred Participants:
All Levels of Mathematics and Physics
Other Requisites:

Technologies for Learning, ETD, MOE 

32 Hr(s)


07/11/2016-10/11/2016 (AM & PM Sessions)








Creating Interactive Electronic Textbook Overview: This 4-day workshop provides a bootstrapping experience to ComPADRE Open Source Physics project and the Easy Java/JavaScript Simulations tool. Objective: Basic how to and explore the Easy Java/JavaScript Simulations (EjsS) modeling and authoring tool.
Create brand new simple mathematical and physics computational model
remix existing models in the digital libraries, especially the Singapore Library.
create or remix one model based on an existing example in the library
export 1 to 2 existing model with supporting text into an epub file as an electronic interactive textbook-chapter. Content: Introduction to the workshop
Exploration of the OSP-EJS-ComPADRE Platform
Exploration of EjsS
Independent work and consultations on curriculum design
Creating simple models with EJS
Creating models with EJS part 2
Remixing one model
Exporting as epub
Reflecting/presenting teacher performance task sharing

Target Audience: Level: All Levels Mathematics and Physics Primary, Secondary & JC/CI

SDF: DG: \) 0

Pre-Requisite:   N.A

Date & Venue:   Begin Date/time:End Date/time:Application Closing Date:Venue:07/11/2016 09:00 - 17:3010/11/2016 09:00 - 17:3023/10/2016edulab@AST, Blk J, Level 4, No: 2, Malan Road, Singapore 109433, Academy of Singapore Teachers, Tel: 66641450Frequency:   


Please bring your SSOE Notebooks with fully charged Battery.


Course Administrator: Organising Agency: Name:    Neo Chin Heng Technologies for Learning, ETD, MOE Phone:    66641450   Email:    

Trainer: Training Agency: Prof Francisco, Prof Wolfgang University of Murcia (Spain), Davidson College USA, Educational Technology Division (MOE)

Assessment Mode:   Nil

No. of Applications: Max. Class Size: 3 30



Date: 7-Nov to 10-Nov Title: Creating Interactive Electronic Textbook

Time: 0900 - 1730 hours 

Loo Kang 

University of Murcia, Spain

Davidson College USA

Prof Francisco Esquembre

Prof Wolfgang Christian


Lawrence WEE


Installation and Tools required, Day 0


  • Recommended to bring and use a personal laptop with admin rights to install software, edulab has 18 windows laptop to be shared. Software needed for the workshop include another list from Prof. Wolfgang
  • Windows/Mac Laptop need these
    • EJSS authoring tool Direct Download  recommended official
    • Bluegriffon XHTML and HTML editor for page creation for epub
    • Chrome Browser
      • Readium An ePub 3 reader plugin for Google Chrome. This plugin reads ePub books stored on a local computer
      • Readiator EPUB Reader shenzhuxi Open source EPUB reader with full EPUB3 support works offline
    • Java Development Kit, needed to create apps for the iTunes and Google Play stores. Note that the JDK also installs the latest JRE.
    • No installation required for equation conversion from LaTeX to MathML supported by epub
    • eCanCrusher is a simple drag/drop utility to recompress and decompress EPUB folders/directory structures. It converts the folder into an .epub file and vice versa. Both Mac and Windows versions are available
    • IDPF ePub 3 Validator or download this The International Digital Publishing Forum (IDPF) site to provide validation information for EPUB 2 and 3 documents. Validate your ePub documents before you release them!
  • On your iOS devices need iBook App to open epub
  • On your Android devices need Gitden EPub Reader for Android A good Android reader that supports ePub 3 and JavaScript simulations



Proposed Programme

7 Nov 2016

30 pax Beginners’ Workshop edulab@AST by Loo Kang and Tze Kwang

– provide 30 pax beginners’ workshop (model simple physical systems such as constant speed (maybe day2) spring mass with damping using EjSS) in eduLab@AST>

 09h00 - 10h30: Introduction to the workshop, Create a brand new simulation Step-by-step EJSS tutorial

  1. Unzip the EJSS modeling tool
  2. Open the EJSS modeling tool by double-clicking on the icon EjsConsole.jar depending on where you unzip, typically it could be the D Drive for edulab laptops.
  3. the console appears and shortly the editor appears, accept any pop-up and click through any info like author and email, you can do later in your free time. 
  4. If you don't get this page, go to the console and change Programming language to Javascript as epub only runs with JavaScript 
  5. Close the tool click on top right corner X and relaunch it, it should be open as JavaScript in the future as it remembers your preferences 
  6. to create a simulation go to - Model - Evolution - Click to create a page of ODEs Ordinary Differential Equations, after clicking that area, accept the default name Evol Page, you can change the name later if desired 
  7. By now, the Evolution page will look like this 
  8. to move a simple object coordinate (x,y) move to the right with time with velocities (vx,vy), t and time step dt, double click to edit and key in the variables into the inputs fields as shown 
  9. click the green arrow button to generate the simulation, it will prompt to save, choose the default location and give it name or accept the default name Unnamed.ejss 
  10. after File saved successfully Unnamed.ejss, click on the green run button again, EJSS will prompt there is no HTML view, click OK to create the view
  11. Click to the top radio button, HtmlView and Click on the Left panel to create the VIEW as suggested 
  12. to create a 2D PlottingPanel view, click the icon from the right Interface Compound Element and release the button, move the mouse to the position of the Simulation view to drop the correct layer to the view 
  13. the EJSS will automatically create several displayPanel containing a topPanel with a trail and controlPanel with play, init and reset buttons, time label and a blank input field as a startup kit. 
  14.  to create an object, select the first object and click and release and move the mouse over to the position of the plottingPanel and click again to drop the 2D object into this position 
  15. accept the default name by clicking OK 
  16. observe the shape is inserted into the plotting Panel 
  17. to edit any element, double click and a pop up appear with more details about the element shape can be controlled via variables assigned later. in key the variables x and y, sizex and sizey, shapetype "ellipse for circle" line and fill color for determining properties of the shape
  18. notice the pink color indicates EJSS does not understand what they are, so go to the Variables radio button to create these new variables you define, accept the default names when prompted 
  19. double click on the Name and key in the variables for this simulation, t, dt, x, y, vx, vy etc 
  20. trying to run the simulation and the simulation is still not rendering correctly.
  21. now, key in Initial value for the variables, t = 0, dt = 0.05, x =0, y =0, vx =0.1, vy = 0 for example to create an object to move to the left at velocity vx =0.1 
  22. Time to think, reflect with your neighbor how to make an object move to the 
    1. left but faster 
    2. up  
    3. down 
    4. diagonal across 45 degrees to the right 
  23. test out whether your simulation can do what you discussed, then click on the picture hints to expand the pictures
  24. 10h30 - 11h00 Networking and Tea Break
  25. Controlling the view of the plottingPanel using variables xmin, xmax, ymin, ymax
  26. notice the simulation you may want to control to make the view bigger say xmin = -2, xmax =2, ymin= -2, ymax =2, to do that, create a new tab (for ease of making your work understandable) by right click and declare these variables in the variable page 
  27. in the new tab, create the variables as shown 
  28. click on the radio button HtmlView and double click on the plottingPanel 
  29. the inputs field control the properties of the plottingPanel, key in as shown 
  30. to test your simulation, click green button run to generate the model, the output view should look something like this
  31. Create a trail that shows where the object was before above the object
  32. to move the layering position of elements right click and select the desired move, for this case, select move down 
  33. to create a trail that follows the coordinates (x,y), key in a show and add 
    1. { "stroke-dasharray":"8 8 8 8" } 
  34. that creates a dotted line effect. run the simulation to test the result and it should look something like this
  35. Simulation do not autostart by default
  36. to disable auto , go to Evolution, uncheck the autoplay checkbox 
  37. Create a slider to allow inquiry
  38. go to HtmlView, Interface last tab, first icon for slider, click and release the mouse move your cursor and click on the playPauseButton
  39. the slider should be create above the playPauseButton as show
  40. double click on the slider to edit the input field of the slider to control what variables you have, for example x position or vx velocity etc 
  41. run the simulation to test your changes. so i change the slider, did the simulation behave as you designed?

    vx slider after dragging left and right a few times

  42. Create a checkbox for turning off and on the visual of the trail
  43. goto radio HtmlView Interface 3 tab top, 4 icon checkbox and click to select, release the mouse and move to the position of the slider and click to drop the checkbox, accept the default name 
  44. double click on the checkbox just created and insert the following variable showv and text to show
  45. again, the Checked field is pink suggesting EJSS cannot understand it, so go to the Variables radio button and key in Variable name showv Type is boolean 
  46. run the simulation to test the results 
  47. Creating numbers to show in simulation
  48. one easy way to create numbers to show is Field, goto HtmlView, Interface 4 tab 4 icon and click to select release the mouse and move over to the position to place the Field say after the slider, right click to move down if need 
  49. double click on the just created field, key in the Value vx, Format "0.0" Width 30 , Background "Magenta" and Tooltip "velocity in x direction"
  50. the run of the simulation will be something like this 
  51. Remove messagesLabel
  52. right click on the view element you want to remove, select the option Cut or Remove 

  53. practice removing the timeLabel and timeField as well on your own 
  54. run simulation to check
  55. Calculate velocity from vx and vy
  56. at every time step of the simulation, you want the magnitude of velocity to be computed and displayed, we use the Fixed relations to compute, click to create a page of fixed relations 
  57. type in an equation say 
    • v = Math.sqrt(vx*vx+vy*vy);
  58.  notice EJSS will help you with prompts after the function Math.
  59. completed the equation and trying the compiler will result in an error or not, but goto Variable page to declare v 
  60. Copying
  61. one of best time about EJSS is the ability to copy, so copy the Field and paste it onto the control panel 
  62. paste into the controlPanel, it will go all the way to the bottom
  63. change the properties as shown 
  64. Insert a Label on top of the newly created field2 which is variable v and add text v = 
  65. key in v = into the Text as shown 
  66. run your simulation to check does it look like this? if not, why? 
  67. Insert pictures
  68. it is possible, i will show one best practice way if the simulation is called Unnamed.ejss, locate the workspace and create a folder to store pictures for the simulation, to find out what, look at your console, for me, it is /Users/lookang/Dropbox/Public/lookangEJSworkspace
  69.  using your file explorer or otherwise, create a new folder of the same name as your *.ejss 
  70. it should look like this 
  71. to EJSS know the source file has auxiliary files, go to top right corner click on information and select the folder created and agree OK 
  72. Cyberwellness find creative commons licenses pictures from Google
  73. using chrome, search for pictures you want to add 
  74. download the picture and save it into that folder Unnamed, select png files are better with transparency 

    By Pumbaa80 (Self-published work by Pumbaa80) [GFDL ( or CC BY-SA 3.0 (], via Wikimedia Commons

  75. select the image 2D and drop it onto the desired position on the plottingPanel 
  76. make the image share property of the earlier element shape and in the ImageURL select the path of the picture for example  "./Unnamed/256px-Soccer_ball.svg.png" 
  77. run the simulation to check 
  78. Increase size of Image
  79. go to image and change SizeX and SizeY to say 0.5 for both, 
  80. run the sim 
  81. Preparing for mobile deployment
  82. to maximise the size of the plottingPanel in the code into the plottingPanel 
    • +_view._format(window.innerWidth*0.9,"0")
    • +_view._format(window.innerHeight*0.9,"0")
  83. run to check 
  84. How to make the ball round?
  85. to create a round ball, set the square aspect to true 
  86. run and sim to check 
  87. Enable User Interaction
  88. go to plottingPanel Interaction Enable select True 
  89. go to the image and select EnabledPosition to "ENABLED_ANY" 
  90. run and check 
  91. Axes that always align to XFixedTick, YFixedTick for graphing norms
  92. go to initialization radio button and create a page 
  93. insert the follow code 
    • // double slashes are comments lines that computer will ignore, to help you read and understand
    • //coordinates are absolute that assume xmin=0, xmax=1,ymin=0, ymax=1 
    • // set x axis referencing left corner of x-axis 
    • _view.plottingPanel.getAxisX().setPosition([0,0.5]);  
    • // set position of x-axis title 
    •  _view.plottingPanel.getTitleX().setPosition([0.95,0.5]); 
    • // set y axis referencing left corner of y-axis 
    • _view.plottingPanel.getAxisY().setPosition([0.5,0]); 
    • // set position of y-axis title 
    • _view.plottingPanel.getTitleY().setPosition([0.5,0.95]);
  94. run and check the result 
  95. Removing the gutter/border to increase view
  96. find this screen and insert [0,0,0,0] where the order of the number gutter width is  [left,top,right,bottom] 
  97. run the sim 
  98. Making the axis nicely spaced
  99. go to plottingPanel and key in the values as shown 

  100. run a sim to check 
  101. Insert a picture to fill up the maximum plottingPanel view

  102. to add a new tab and called it picturesize in the Initialization page 
    • orig_listener = _view.plottingPanel.getAxisX().panelChangeListener; _view.plottingPanel.getAxisX().panelChangeListener = function(e) { orig_listener(e); _view.backgroundsoccerfield.setSizeX(_view.plottingPanel.getRealWorldXMax()-_view.plottingPanel.getRealWorldXMin()); _view.backgroundsoccerfield.setSizeY(_view.plottingPanel.getRealWorldYMax()-_view.plottingPanel.getRealWorldYMin()); }
  103. add a picture of into the plottingPlanel using the screenshot as guide
  104. run sim to check  
  105. Creating an goalpost for making the ball stop just at the collision
  106. in simulations, it is a good idea to make object stop at the moment of collision, for very precise calculations, which is difficult to achieve. In EJSS, it is simple.
  107. First create the goalpost by creating an object using the screenshots as a guide, now that you have done this before for the ball call it coordinates (x1, y1), size (0.5, 0.5), shapetype "RECTANGLE", RelativePosition "WEST" FillColor "Yellow"
  108. Declare the variables in the Variable page 
  109. run and see the result 
  110. Disabling codes using Tabs
  111. remember in the view, xmin, xmax ymin, ymax are -2 and 2 respectively but the computer view goes to -4 and 4 for x, because EJSS automatically shows the best view. it is great, but for this example, we want to restrict the view to exactly xmin, xmax ymin, ymax for precise placement of the goalpost so that the background is in sync with the yellow goalpost. EJSS allow very fast testing of codes so go to Initialization right click and choose disable and EJSS will not generate the codes inside this tab called picturesize 
  112. run the sim to check the view 
  113. in any modeling tool, everything needs to be precise if it is not, a lot of funny things can happen
  114. Using Math functions in any part of the simulation
  115. to restrict the simulation view of the plottingPanel, use a mathematical function called Math.min(one,two) that calculates the lower value
    • +_view._format(Math.min(window.innerWidth*0.9,window.innerHeight*0.9),"0")
    • +_view._format(Math.min(window.innerWidth*0.9,window.innerHeight*0.9),"0")
  116. put this line inside the plottingPanel Width and Height 
  117. run and see 
  118. got to Evolution click Events and create a page 
  119. on the Event page, change the zero condition and action as follow 
    •  return x - x1
    • vx = 0;
    • vy = 0; // stop the ball
  120. you may need to change vy =0 to make the ball travel to the goalpost
  121. run and see the result 
  122. Debugging and Seeing the results
  123. one way to quickly see the result is "x ="+_view._format(x,"0.00");
    • "x1 ="+_view._format(x1,"0.00")
    • "x ="+_view._format(x,"0.00")
  124. type this two lines inside plottingPanel Decoration the BRMessage and BLMessage respectively 
  125. run and see 
  126. Disabling to see effects of change
  127. how to know that the changes made is indeed the reason? try to disable that page and see 
  128. run and see 
  129. continuing with the rest of the activity, enable back the event page 
  130. Creativity Practice to add score
  131. you may want to add a score after each successful event. Try it!
  132. hints are below 
    1. score = score+1; // tells the score to add by 1 when this line is executed 
    2. "score ="+_view._format(score,"0")
  133. Practice moving the ball back to the centre after scores, Falding Scaffolds
    • x = 0; 
    • y = 0;
  134. run and see 
  135. FullScreen on browsers using custom function
  136. After googling full screen, you may find this page and wonder how to use the codes there 
  137. go to Custom and add this code to enable fullscreen 
  138. copy this code into the custom page
    •  //
    • // does not work for iOS 
    • /*jslint browser:true */
    • function toggleFullScreen() {
    •   if (!document.fullscreenElement &&    // alternative standard method
    •       !document.mozFullScreenElement && !document.webkitFullscreenElement && !document.msFullscreenElement ) {  // current working methods
    •     if (document.documentElement.requestFullscreen) {
    •       document.documentElement.requestFullscreen();
    •     } else if (document.documentElement.msRequestFullscreen) {
    •       document.documentElement.msRequestFullscreen();
    •     } else if (document.documentElement.mozRequestFullScreen) {
    •       document.documentElement.mozRequestFullScreen();
    •     } else if (document.documentElement.webkitRequestFullscreen) {
    •       document.documentElement.webkitRequestFullscreen();
    •     }
    •   } else {
    •     if (document.exitFullscreen) { //Standard
    •       document.exitFullscreen();
    •     } else if (document.msExitFullscreen) { //Internet Explorer 11
    •       document.msExitFullscreen();
    •     } else if (document.mozCancelFullScreen) { //Gecko (Firefox)
    •       document.mozCancelFullScreen();
    •     } else if (document.webkitExitFullscreen) { //Safari (WebKit)
    •       document.webkitExitFullscreen();
    •     }
    •   }
    • }
  139. download this iconand add to the Unnamed folder 
  140. create the button to toggleFullScreen custom function
  141. add Disabled _isPlaying ImageOnUrl to be "./Unnamed/full_screen.png" OnClick toggleFullScreen() ImageOffUrl "/org/opensourcephysics/resources/controls/images/close.gif" and OffClick toggleFullScreen() 
  142. run and see 
  143. Hitting the left border and stop
  144. to create precise time to stop, EJSS can do this easily using Event instead of FixedRelationship which will overshoot during the time step dt.
  145. goto Event, start a new tab and name it LeftWall 
  146. in this LeftWall, think of a way to what is the condition needed for precise calculation of the event. your code should be something like this 
    1. return x-0.5/2-xmin; //recall 0.5 was diameter of ball
    2. vx = -vx; // give the velocity back but reverse direction
  147. run and check 
  148. Ease of change, name the variable size = 0.5 and add to the LeftWall event
  149. define size as 0.5 
  150. change the LeftWall event
    • return x-size/2-xmin; //recall 0.5 was diameter of ball 
  151. the benefits of variabilization is ease of change later on
  152. continue to work on your simulation to include
    • collision with top ymax 
    • collision with bottom ymin 
    • collision with xmax including the goalpost 
  153. hint is available if need by clicking the images
  154. Creating model and source for sharing online
  155. right click the right package option and choose the first 2 options 
  156. is the simulation, give it to your students, ask them to unzip it and launch the file that looks like the simulation, for example, Unnamed_Simulation.xhtml, test my copy on how it looks 
  157. is the source code for which you want others to edit the simulations
  158. 12h15 - 12h30: Reflection, did we cover most of the EJSS simulation creation in a purposeful, just in time manner? 
    1. Exploration of EjsS,EjsS workspace fundamentals
      Structure of a model in EJS
      Variables and their types.
      Initialization, fixed relations, and custom functions
      Introduction to the ODE editor and the Prelim code page
      Binding model variables to view elements and controls
      How to deploy simulation model and source
  159. lunch until 1400


Day 1 Afternoon

14h00 - 17h30: Load, inspect, and run a JavaScript simulation from within EjsS


Modify a simulation Pendulum 195 chosen to suit O level syllabus (assistance will be given to help with the modifications)

 on OSP@SGExploration of the OSP-EJS-ComPADRE-OSP@SG Platform



ebook creation using OSP tools and Independent work and consultations on curriculum design referencing some of the teachers of eduLab project 40+ simulation in



15h30 - 16h00: Break and Networking


1600-1730 ebook creation using OSP tools What is the UNESCO Singapore ICT mathematical pedagogical innovation about? open this source code to examine that additional codes added for this mathematically modeling approach with if statements.

Updated for Hackathon 2019 

For Teachers








Other Resources


end faq

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