{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":361,"title":"Energy of a photon","description":"\u0026#9883 \u0026#9762 \u0026#9883 \u0026#9762 \u0026#9883 \u0026#9762 \u0026#9883\r\nGiven the frequency F of a photon in giga hertz.\r\nFind energy E of this photon in giga electron volts.\r\nAssume h, Planck's constant is about 4 femto electron-volt-second.\r\nTo maximize benefits, it may help not looking at the Test Suite before trying any solution!\r\nFor more info: \u003chttps://en.wikipedia.org/wiki/Planck_constant\u003e","description_html":"\u003cdiv style = \"text-align: start; line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 171px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 85.5px; transform-origin: 407px 85.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 187px 8px; transform-origin: 187px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003e\u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 151px 8px; transform-origin: 151px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eGiven the frequency F of a photon in giga hertz.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 158.5px 8px; transform-origin: 158.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eFind energy E of this photon in giga electron volts.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 211px 8px; transform-origin: 211px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eAssume h, Planck's constant is about 4 femto electron-volt-second.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 276.5px 8px; transform-origin: 276.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eTo maximize benefits, it may help not looking at the Test Suite before trying any solution!\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 44.5px 8px; transform-origin: 44.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eFor more info:\u003c/span\u003e\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 2px 8px; transform-origin: 2px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"https://en.wikipedia.org/wiki/Planck_constant\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003e\u0026lt;https://en.wikipedia.org/wiki/Planck_constant\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 4px 8px; transform-origin: 4px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e\u0026gt;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function E = photon_energy(F)\r\n  E=100/F;\r\nend","test_suite":"%%\r\nF = 1;\r\nE_correct = 3/10^15;\r\nassert(photon_energy(F)\u003eE_correct)\r\n%%\r\nF = 100;\r\nE_correct = 500/10^15;\r\nassert(photon_energy(F)\u003cE_correct)\r\n%%\r\nF = 500;\r\nE_correct = 2100/10^15;\r\nassert(photon_energy(F)\u003cE_correct)\r\n%%\r\nF = 420;\r\nE_correct = 1680/10^15;\r\nassert(isequal(photon_energy(F),E_correct))\r\n%%\r\nF = 0.25;\r\nE_correct = 1e-15;\r\nassert(isequal(photon_energy(F),E_correct))","published":true,"deleted":false,"likes_count":16,"comments_count":12,"created_by":166,"edited_by":223089,"edited_at":"2022-12-24T15:16:49.000Z","deleted_by":null,"deleted_at":null,"solvers_count":1471,"test_suite_updated_at":"2022-12-24T15:16:49.000Z","rescore_all_solutions":false,"group_id":34,"created_at":"2012-02-19T23:13:56.000Z","updated_at":"2026-05-08T02:49:03.000Z","published_at":"2017-10-16T01:45:05.000Z","restored_at":null,"restored_by":null,"spam":null,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e\u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the frequency F of a photon in giga hertz.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFind energy E of this photon in giga electron volts.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssume h, Planck's constant is about 4 femto electron-volt-second.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eTo maximize benefits, it may help not looking at the Test Suite before trying any solution!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor more info:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Planck_constant\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://en.wikipedia.org/wiki/Planck_constant\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":44372,"title":"Polarisation","description":"You have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? For more information, see \u003chttps://en.wikipedia.org/wiki/Polarizer Polarizer (Wikipedia)\u003e.\r\n\r\n    \u003e\u003e n = [0, 90];\r\n    \u003e\u003e polarised([0, 90])\r\n\r\n    ans = 0","description_html":"\u003cp\u003eYou have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? For more information, see \u003ca href = \"https://en.wikipedia.org/wiki/Polarizer\"\u003ePolarizer (Wikipedia)\u003c/a\u003e.\u003c/p\u003e\u003cpre\u003e    \u0026gt;\u0026gt; n = [0, 90];\r\n    \u0026gt;\u0026gt; polarised([0, 90])\u003c/pre\u003e\u003cpre\u003e    ans = 0\u003c/pre\u003e","function_template":"function y = polarised(x)\r\n  y = max(x);\r\nend","test_suite":"%%\r\nx = 5;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 180;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 365;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [91, 1];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\na = randi([-360, 360]);\r\nb = 90*(1+2*randi([-3, 3]));\r\nx = [a, a+b];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\na = randi([-360, 360]);\r\nb = 90*(1+2*randi([-3, 3]));\r\nx = [a, a+b];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [0, 22.5];\r\ny_correct = 0.85355339059/2;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [0, -45];\r\ny_correct = 0.25;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [5, 140];\r\ny_correct = 0.25;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 5 + (1:5)*22.5;\r\ny_correct = 0.53079004294/2;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":4,"comments_count":10,"created_by":14358,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":272,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":34,"created_at":"2017-10-10T21:58:52.000Z","updated_at":"2026-05-29T07:47:34.000Z","published_at":"2017-10-16T01:45:10.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? 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line-height: 20.4333px; min-height: 0px; white-space: normal; color: rgb(0, 0, 0); font-family: Menlo, Monaco, Consolas, monospace; font-style: normal; font-size: 14px; font-weight: 400; text-decoration: rgb(0, 0, 0); white-space: normal; \"\u003e\u003cdiv style=\"block-size: 171px; display: block; min-width: 0px; padding-block-start: 0px; padding-top: 0px; perspective-origin: 407px 85.5px; transform-origin: 407px 85.5px; vertical-align: baseline; \"\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 187px 8px; transform-origin: 187px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"font-weight: 700; \"\u003e\u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 151px 8px; transform-origin: 151px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eGiven the frequency F of a photon in giga hertz.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 158.5px 8px; transform-origin: 158.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eFind energy E of this photon in giga electron volts.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 211px 8px; transform-origin: 211px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eAssume h, Planck's constant is about 4 femto electron-volt-second.\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 276.5px 8px; transform-origin: 276.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eTo maximize benefits, it may help not looking at the Test Suite before trying any solution!\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv style=\"block-size: 21px; font-family: Helvetica, Arial, sans-serif; line-height: 21px; margin-block-end: 9px; margin-block-start: 2px; margin-bottom: 9px; margin-inline-end: 10px; margin-inline-start: 4px; margin-left: 4px; margin-right: 10px; margin-top: 2px; perspective-origin: 384px 10.5px; text-align: left; transform-origin: 384px 10.5px; white-space: pre-wrap; margin-left: 4px; margin-top: 2px; margin-bottom: 9px; margin-right: 10px; \"\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 44.5px 8px; transform-origin: 44.5px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003eFor more info:\u003c/span\u003e\u003c/span\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 2px 8px; transform-origin: 2px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e \u003c/span\u003e\u003c/span\u003e\u003ca target='_blank' href = \"https://en.wikipedia.org/wiki/Planck_constant\"\u003e\u003cspan style=\"\"\u003e\u003cspan style=\"\"\u003e\u0026lt;https://en.wikipedia.org/wiki/Planck_constant\u003c/span\u003e\u003c/span\u003e\u003c/a\u003e\u003cspan style=\"block-size: auto; display: inline; margin-block-end: 0px; margin-block-start: 0px; margin-bottom: 0px; margin-inline-end: 0px; margin-inline-start: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; perspective-origin: 4px 8px; transform-origin: 4px 8px; unicode-bidi: normal; \"\u003e\u003cspan style=\"\"\u003e\u0026gt;\u003c/span\u003e\u003c/span\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e","function_template":"function E = photon_energy(F)\r\n  E=100/F;\r\nend","test_suite":"%%\r\nF = 1;\r\nE_correct = 3/10^15;\r\nassert(photon_energy(F)\u003eE_correct)\r\n%%\r\nF = 100;\r\nE_correct = 500/10^15;\r\nassert(photon_energy(F)\u003cE_correct)\r\n%%\r\nF = 500;\r\nE_correct = 2100/10^15;\r\nassert(photon_energy(F)\u003cE_correct)\r\n%%\r\nF = 420;\r\nE_correct = 1680/10^15;\r\nassert(isequal(photon_energy(F),E_correct))\r\n%%\r\nF = 0.25;\r\nE_correct = 1e-15;\r\nassert(isequal(photon_energy(F),E_correct))","published":true,"deleted":false,"likes_count":16,"comments_count":12,"created_by":166,"edited_by":223089,"edited_at":"2022-12-24T15:16:49.000Z","deleted_by":null,"deleted_at":null,"solvers_count":1471,"test_suite_updated_at":"2022-12-24T15:16:49.000Z","rescore_all_solutions":false,"group_id":34,"created_at":"2012-02-19T23:13:56.000Z","updated_at":"2026-05-08T02:49:03.000Z","published_at":"2017-10-16T01:45:05.000Z","restored_at":null,"restored_by":null,"spam":null,"simulink":false,"admin_reviewed":false,"description_opc":"{\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003e\u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883 \u0026amp;#9762 \u0026amp;#9883\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eGiven the frequency F of a photon in giga hertz.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFind energy E of this photon in giga electron volts.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAssume h, Planck's constant is about 4 femto electron-volt-second.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eTo maximize benefits, it may help not looking at the Test Suite before trying any solution!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003cw:jc w:val=\\\"left\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor more info:\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Planck_constant\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://en.wikipedia.org/wiki/Planck_constant\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\",\"relationship\":null}],\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"target\":\"/matlab/document.xml\",\"relationshipId\":\"rId1\"}]}"},{"id":44372,"title":"Polarisation","description":"You have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? For more information, see \u003chttps://en.wikipedia.org/wiki/Polarizer Polarizer (Wikipedia)\u003e.\r\n\r\n    \u003e\u003e n = [0, 90];\r\n    \u003e\u003e polarised([0, 90])\r\n\r\n    ans = 0","description_html":"\u003cp\u003eYou have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? For more information, see \u003ca href = \"https://en.wikipedia.org/wiki/Polarizer\"\u003ePolarizer (Wikipedia)\u003c/a\u003e.\u003c/p\u003e\u003cpre\u003e    \u0026gt;\u0026gt; n = [0, 90];\r\n    \u0026gt;\u0026gt; polarised([0, 90])\u003c/pre\u003e\u003cpre\u003e    ans = 0\u003c/pre\u003e","function_template":"function y = polarised(x)\r\n  y = max(x);\r\nend","test_suite":"%%\r\nx = 5;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 180;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 365;\r\ny_correct = 0.5;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [91, 1];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\na = randi([-360, 360]);\r\nb = 90*(1+2*randi([-3, 3]));\r\nx = [a, a+b];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\na = randi([-360, 360]);\r\nb = 90*(1+2*randi([-3, 3]));\r\nx = [a, a+b];\r\ny_correct = 0;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [0, 22.5];\r\ny_correct = 0.85355339059/2;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [0, -45];\r\ny_correct = 0.25;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = [5, 140];\r\ny_correct = 0.25;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n%%\r\nx = 5 + (1:5)*22.5;\r\ny_correct = 0.53079004294/2;\r\nassert(abs(polarised(x)-y_correct) \u003c 1e-10)\r\n\r\n\r\n\r\n","published":true,"deleted":false,"likes_count":4,"comments_count":10,"created_by":14358,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":272,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":34,"created_at":"2017-10-10T21:58:52.000Z","updated_at":"2026-05-29T07:47:34.000Z","published_at":"2017-10-16T01:45:10.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou have n polarising filters stacked one on top of another, and you know each axis angle. How much light gets passed through the filter bank? For more information, see\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:hyperlink w:docLocation=\\\"https://en.wikipedia.org/wiki/Polarizer\\\"\u003e\u003cw:r\u003e\u003cw:t\u003ePolarizer (Wikipedia)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[    \u003e\u003e n = [0, 90];\\n    \u003e\u003e polarised([0, 90])\\n\\n    ans = 0]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[{"value":"Cody5:Easy","count":2,"selected":false}],[{"value":"medium","count":2,"selected":false}]],"term":"tag:\"quantum\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}