{"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":43573,"title":"Extract part elements of matrix into one new matrix","description":"Given a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\r\n\r\nFor example, for the input:\r\n\r\n a = [0 1 0; 1 0 2; 4 3 -5]\r\n\r\nthe output should be:\r\n\r\n [1 1 2; 4 3 -5]\r\n","description_html":"\u003cp\u003eGiven a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\u003c/p\u003e\u003cp\u003eFor example, for the input:\u003c/p\u003e\u003cpre\u003e a = [0 1 0; 1 0 2; 4 3 -5]\u003c/pre\u003e\u003cp\u003ethe output should be:\u003c/p\u003e\u003cpre\u003e [1 1 2; 4 3 -5]\u003c/pre\u003e","function_template":"function y = your_fcn_name(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = [0 1 0; 1 0 2; 4 3 -5];\r\ny_correct = [1 1 2;4 3 -5];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n%%\r\nx = [0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n712893\t1951\t11\t1\t-1.38\r\n712894\t1951\t11\t2\t-2.56\r\n712895\t1951\t11\t3\t-2.68];\r\ny_correct = [712893\t1951\t11\t1\t-1.38\r\n             712894\t1951\t11\t2\t-2.56\r\n             712895\t1951\t11\t3\t-2.68];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n%%\r\nx = [1 2 3 -13; 0 0 0 0; -5 9 7 6;0 0 0 0];\r\ny_correct = [1 2 3 -13; -5 9 7 6];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":1,"created_by":4570,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":47,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-18T05:43:28.000Z","updated_at":"2026-05-29T01:44:46.000Z","published_at":"2016-10-18T05:48:53.000Z","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\u003eGiven a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\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, for the input:\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[ a = [0 1 0; 1 0 2; 4 3 -5]]]\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\u003ethe output should 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[ [1 1 2; 4 3 -5]]]\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\"}]}"}],"problem_search":{"problems":[{"id":43573,"title":"Extract part elements of matrix into one new matrix","description":"Given a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\r\n\r\nFor example, for the input:\r\n\r\n a = [0 1 0; 1 0 2; 4 3 -5]\r\n\r\nthe output should be:\r\n\r\n [1 1 2; 4 3 -5]\r\n","description_html":"\u003cp\u003eGiven a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\u003c/p\u003e\u003cp\u003eFor example, for the input:\u003c/p\u003e\u003cpre\u003e a = [0 1 0; 1 0 2; 4 3 -5]\u003c/pre\u003e\u003cp\u003ethe output should be:\u003c/p\u003e\u003cpre\u003e [1 1 2; 4 3 -5]\u003c/pre\u003e","function_template":"function y = your_fcn_name(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nx = [0 1 0; 1 0 2; 4 3 -5];\r\ny_correct = [1 1 2;4 3 -5];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n%%\r\nx = [0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n0\t0\t0\t0\t0\r\n712893\t1951\t11\t1\t-1.38\r\n712894\t1951\t11\t2\t-2.56\r\n712895\t1951\t11\t3\t-2.68];\r\ny_correct = [712893\t1951\t11\t1\t-1.38\r\n             712894\t1951\t11\t2\t-2.56\r\n             712895\t1951\t11\t3\t-2.68];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n%%\r\nx = [1 2 3 -13; 0 0 0 0; -5 9 7 6;0 0 0 0];\r\ny_correct = [1 2 3 -13; -5 9 7 6];\r\nassert(isequal(your_fcn_name(x),y_correct))\r\n","published":true,"deleted":false,"likes_count":0,"comments_count":1,"created_by":4570,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":47,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-18T05:43:28.000Z","updated_at":"2026-05-29T01:44:46.000Z","published_at":"2016-10-18T05:48:53.000Z","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\u003eGiven a matrix that includes different nonzero and zero entries, extract the nonzero elements and form a new matrix. The new matrix should maintain the same number of columns.\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, for the input:\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[ a = [0 1 0; 1 0 2; 4 3 -5]]]\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\u003ethe output should 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[ [1 1 2; 4 3 -5]]]\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":"medium","count":1,"selected":false}]],"term":"tag:\"nonzero\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}