// Numbas version: exam_results_page_options
{"name": "Draw a 3d plot with vis.js", "extensions": ["visjs", "stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Draw a 3d plot with vis.js", "parts": [], "extensions": ["stats", "visjs"], "functions": {"listsum": {"parameters": [["lists", "list"]], "language": "jme", "type": "number", "definition": "if(len(lists)>0,lists[0]+listsum(lists[1..len(lists)]),[])"}, "sample_peak": {"parameters": [["x_mean", "number"], ["x_sd", "number"], ["y_mean", "number"], ["y_sd", "number"]], "language": "jme", "type": "number", "definition": "// generate a load of samples from a 2D normal distribution\nrepeat(\n    [round(normalsample(x_mean,x_sd)),round(normalsample(y_mean,y_sd))],\n    10000\n  )"}, "gatherpoints": {"parameters": [["data", "list"]], "language": "javascript", "type": "list", "definition": "// count the number of points at each coordinate\n// takes a list of [x,y] coordinates representing points\n// returns a list of data of the form [x,y,count]\n\ndata = data.sort(function(a,b){return a[0]<b[0] ? -1 : a[0]>b[0] ? 1 : a[1]<b[1] ? -1 : a[1]>b[1] ? 1 : 0});\nvar out = [];\nfor(var i=0;i<data.length;i++) {\n  var x = data[i][0];\n  var y = data[i][1];\n  var t = 0;\n  while(i<data.length && data[i][0]==x && data[i][1]==y) {\n    t += 1;\n    i += 1;\n  }\n  out.push([x,y,t]);\n}\nreturn out;"}}, "ungrouped_variables": ["data", "centres"], "advice": "", "statement": "<h4>A plot of a function</h4>\n<p>\\[ \\simplify{sin(x/50)*cos(x/50)*50+50} \\]</p>\n<p>{plot3dfunction(sin(x/50) * cos(y/50) * 50 + 50,x,0..300#6,y,0..300#6)}</p>\n<h4>Some random data</h4>\n<p>{plot3dpoints(data)}</p>\n<h4>Boxes instead of a surface</h4>\n<div id=\"boxes\">Boxes go here</div>", "rulesets": {}, "variables": {"centres": {"name": "centres", "templateType": "anything", "description": "", "definition": "repeat(let(d,random(2..4),[random(-5..5),d,random(-5..5),d]),3)", "group": "Ungrouped variables"}, "data": {"name": "data", "templateType": "anything", "description": "<p>Some interesting-looking data: sum a few 2D normal distributions with different centres.</p>", "definition": "gatherpoints(listsum(map(sample_peak(c[0],c[1],c[2],c[3]),c,centres)))", "group": "Ungrouped variables"}}, "tags": [], "preamble": {"css": "", "js": "question.onHTMLAttached(function() {\n  var expr = Numbas.jme.compile('x*x-y*y');\n  var xvals = (new Numbas.jme.types.range([-5,5,1])).value.slice(3);\n  var yvals = (new Numbas.jme.types.range([-5,5,1])).value.slice(3);\n  var options = {\n    verticalRatio: 0.5,\n    style: 'bar-size'\n  }\n  var graph = Numbas.extensions.visjs.plot3dfunction(expr,question.scope,'x',xvals,'y',yvals,options);\n  $(question.display.html).find('#boxes').html(graph.containerElement);\n})"}, "variable_groups": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>This question uses the vis.js library to&nbsp;plot 3D functions and data sets.</p>\n<p>As well as JME functions to make plots, you can use javascript functions to get more control over how the&nbsp;plots are rendered.</p>"}, "type": "question", "contributors": [{"name": "Hina Ahmed", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1160/"}]}]}], "contributors": [{"name": "Hina Ahmed", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1160/"}]}