{"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":2062,"title":"A matrix of introverts","description":"You are given a matrix full of numbers who happen to be very shy.  Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire.  This should include a border of zeros around the outside of the matrix.\r\n\r\nFor example, if your input matrix is magic(3):\r\n\r\n [8 1 6\r\n  3 5 7\r\n  4 9 2]\r\n\r\nyour output will be:\r\n \r\n [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0]\r\n\r\nPlease help them out, but do so quietly; they don't like the attention very much.","description_html":"\u003cp\u003eYou are given a matrix full of numbers who happen to be very shy.  Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire.  This should include a border of zeros around the outside of the matrix.\u003c/p\u003e\u003cp\u003eFor example, if your input matrix is magic(3):\u003c/p\u003e\u003cpre\u003e [8 1 6\r\n  3 5 7\r\n  4 9 2]\u003c/pre\u003e\u003cp\u003eyour output will be:\u003c/p\u003e\u003cpre\u003e [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0]\u003c/pre\u003e\u003cp\u003ePlease help them out, but do so quietly; they don't like the attention very much.\u003c/p\u003e","function_template":"function y = introverts(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = magic(3);\r\ny_correct =  [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=1;\r\ny_correct=[0 0 0 ; 0 1 0 ; 0 0 0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=[1 2 3 ; 4 5 6];\r\ny_correct=[0     0     0     0     0     0     0\r\n     0     1     0     2     0     3     0\r\n     0     0     0     0     0     0     0\r\n     0     4     0     5     0     6     0\r\n     0     0     0     0     0     0     0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=[1:6]';\r\ny_correct=[     0     0     0\r\n     0     1     0\r\n     0     0     0\r\n     0     2     0\r\n     0     0     0\r\n     0     3     0\r\n     0     0     0\r\n     0     4     0\r\n     0     0     0\r\n     0     5     0\r\n     0     0     0\r\n     0     6     0\r\n     0     0     0];\r\nassert(isequal(introverts(x),y_correct));\r\n%%\r\nx=zeros(12);\r\ny_correct=zeros(25);\r\nassert(isequal(introverts(x),y_correct))","published":true,"deleted":false,"likes_count":8,"comments_count":2,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":75,"test_suite_updated_at":"2013-12-18T17:50:24.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2013-12-18T17:47:09.000Z","updated_at":"2026-04-01T02:20:34.000Z","published_at":"2013-12-18T17:50:24.000Z","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 are given a matrix full of numbers who happen to be very shy. Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire. This should include a border of zeros around the outside of the matrix.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor example, if your input matrix is magic(3):\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[ [8 1 6\\n  3 5 7\\n  4 9 2]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eyour output will be:\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[ [0 0 0 0 0 0 0\\n  0 8 0 1 0 6 0\\n  0 0 0 0 0 0 0\\n  0 3 0 5 0 7 0\\n  0 0 0 0 0 0 0\\n  0 4 0 9 0 2 0\\n  0 0 0 0 0 0 0]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease help them out, but do so quietly; they don't like the attention very much.\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\"}]}"}],"problem_search":{"problems":[{"id":2062,"title":"A matrix of introverts","description":"You are given a matrix full of numbers who happen to be very shy.  Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire.  This should include a border of zeros around the outside of the matrix.\r\n\r\nFor example, if your input matrix is magic(3):\r\n\r\n [8 1 6\r\n  3 5 7\r\n  4 9 2]\r\n\r\nyour output will be:\r\n \r\n [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0]\r\n\r\nPlease help them out, but do so quietly; they don't like the attention very much.","description_html":"\u003cp\u003eYou are given a matrix full of numbers who happen to be very shy.  Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire.  This should include a border of zeros around the outside of the matrix.\u003c/p\u003e\u003cp\u003eFor example, if your input matrix is magic(3):\u003c/p\u003e\u003cpre\u003e [8 1 6\r\n  3 5 7\r\n  4 9 2]\u003c/pre\u003e\u003cp\u003eyour output will be:\u003c/p\u003e\u003cpre\u003e [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0]\u003c/pre\u003e\u003cp\u003ePlease help them out, but do so quietly; they don't like the attention very much.\u003c/p\u003e","function_template":"function y = introverts(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = magic(3);\r\ny_correct =  [0 0 0 0 0 0 0\r\n  0 8 0 1 0 6 0\r\n  0 0 0 0 0 0 0\r\n  0 3 0 5 0 7 0\r\n  0 0 0 0 0 0 0\r\n  0 4 0 9 0 2 0\r\n  0 0 0 0 0 0 0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=1;\r\ny_correct=[0 0 0 ; 0 1 0 ; 0 0 0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=[1 2 3 ; 4 5 6];\r\ny_correct=[0     0     0     0     0     0     0\r\n     0     1     0     2     0     3     0\r\n     0     0     0     0     0     0     0\r\n     0     4     0     5     0     6     0\r\n     0     0     0     0     0     0     0];\r\nassert(isequal(introverts(x),y_correct))\r\n%%\r\nx=[1:6]';\r\ny_correct=[     0     0     0\r\n     0     1     0\r\n     0     0     0\r\n     0     2     0\r\n     0     0     0\r\n     0     3     0\r\n     0     0     0\r\n     0     4     0\r\n     0     0     0\r\n     0     5     0\r\n     0     0     0\r\n     0     6     0\r\n     0     0     0];\r\nassert(isequal(introverts(x),y_correct));\r\n%%\r\nx=zeros(12);\r\ny_correct=zeros(25);\r\nassert(isequal(introverts(x),y_correct))","published":true,"deleted":false,"likes_count":8,"comments_count":2,"created_by":1615,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":75,"test_suite_updated_at":"2013-12-18T17:50:24.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2013-12-18T17:47:09.000Z","updated_at":"2026-04-01T02:20:34.000Z","published_at":"2013-12-18T17:50:24.000Z","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 are given a matrix full of numbers who happen to be very shy. Write a MATLAB function that will put a square of zeros around each term in the matrix, thus giving them the privacy and space they desire. This should include a border of zeros around the outside of the matrix.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eFor example, if your input matrix is magic(3):\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[ [8 1 6\\n  3 5 7\\n  4 9 2]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eyour output will be:\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[ [0 0 0 0 0 0 0\\n  0 8 0 1 0 6 0\\n  0 0 0 0 0 0 0\\n  0 3 0 5 0 7 0\\n  0 0 0 0 0 0 0\\n  0 4 0 9 0 2 0\\n  0 0 0 0 0 0 0]]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease help them out, but do so quietly; they don't like the attention very much.\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":"medium","count":1,"selected":false}]],"term":"tag:\"too much narcissism\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}