// Numbas version: exam_results_page_options
{"name": "Variable testing", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Variable testing", "tags": ["demo"], "metadata": {"description": "<p>Use the testing tab in the variables section to make sure the generated variables satisfy a condition</p>", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "<p>$M = \\var{m}$.</p>\n<p>$|M| = \\var{det(m)}$.</p>\n<hr/>\n<p>The discriminant of $\\simplify{ {a}x^2 + {b}x + {c} }$ is $\\var{discriminant}$.</p>\n<hr/>\n<p>Here's some data:</p>\n<p>{join(data, \", \")}</p>\n<p>The mean is {mean}.</p>", "advice": "", "rulesets": {}, "extensions": [], "variables": {"a": {"name": "a", "group": "Ungrouped variables", "definition": "random(-10..10)", "description": "<p>The $a$ in $ax^2 + bx + c$</p>", "templateType": "anything"}, "c": {"name": "c", "group": "Ungrouped variables", "definition": "random(-10..10)", "description": "<p>The $c$ in $ax^2 + bx + c$</p>", "templateType": "anything"}, "b": {"name": "b", "group": "Ungrouped variables", "definition": "random(-10..10)", "description": "<p>The $b$ in $ax^2 + bx + c$</p>", "templateType": "anything"}, "discriminant": {"name": "discriminant", "group": "Ungrouped variables", "definition": "b^2-4*a*c", "description": "<p>The discriminant of the quadratic function. Should not be negative.</p>", "templateType": "anything"}, "m": {"name": "m", "group": "Ungrouped variables", "definition": "matrix(repeat(repeat(random(-5..5),3),3))", "description": "<p>A random matrix.</p>\n<p>We want its determinant to be non-zero</p>", "templateType": "anything"}, "data": {"name": "data", "group": "Ungrouped variables", "definition": "repeat(random(0..30),100)", "description": "<p>A random set of data.</p>\n<p>We want the mean to be greater than 15.</p>", "templateType": "anything"}, "mean": {"name": "mean", "group": "Ungrouped variables", "definition": "sum(data)/len(data)", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "det(m)<>0  // matrix is non-singular\nand\ndiscriminant>=0  // quadratic formula has real roots\nand\nmean>15  // arbitrary condition on random data!", "maxRuns": 100}, "ungrouped_variables": ["a", "b", "c", "data", "discriminant", "m", "mean"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}]}], "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}