{"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":733,"title":"Extract Built In Functions and Toolbox Functions from String or Function Handle","description":"Find the Built-In functions and Toolbox functions in either a string or a function handle.\r\n\r\nGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\r\n\r\n*Inputs:*\r\n\r\nfh=@(x)log10(x)+log2(x)+abs(x)\r\n\r\nstr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\r\n\r\n*Outputs:*\r\n\r\n'abs log2 log10'\r\n\r\n'abs filter numel sin filter2 smooth3'\r\n\r\nRelated to \r\n\u003chttp://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer Cody_464\u003e","description_html":"\u003cp\u003eFind the Built-In functions and Toolbox functions in either a string or a function handle.\u003c/p\u003e\u003cp\u003eGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\u003c/p\u003e\u003cp\u003e\u003cb\u003eInputs:\u003c/b\u003e\u003c/p\u003e\u003cp\u003efh=@(x)log10(x)+log2(x)+abs(x)\u003c/p\u003e\u003cp\u003estr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutputs:\u003c/b\u003e\u003c/p\u003e\u003cp\u003e'abs log2 log10'\u003c/p\u003e\u003cp\u003e'abs filter numel sin filter2 smooth3'\u003c/p\u003e\u003cp\u003eRelated to  \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer\"\u003eCody_464\u003c/a\u003e\u003c/p\u003e","function_template":"function functions = find_functions(fh_str)\r\n  functions = '';\r\nend","test_suite":"%%\r\nfh_str='log2(x)+smooth3(x,y)+abs(2)+log10(5)';\r\nexp_str='abs log10 log2 smooth3';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='for k=log10(x):log2(x)+abs(x)';\r\nexp_str='abs for log10 log2';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str=@(x)x^2+sin(x)-cos(x);\r\nexp_str='cos sin';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='@(x)x^2+sin(x)-cos(x)';\r\nexp_str='cos sin';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='filter2(x,A)+filter(x)-cos(x) expm(z)';\r\nexp_str='cos filter expm filter2';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)';\r\nexp_str='abs filter numel sin filter2 smooth3';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n","published":true,"deleted":false,"likes_count":5,"comments_count":6,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":84,"test_suite_updated_at":"2012-07-18T13:18:16.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-01T23:09:01.000Z","updated_at":"2026-05-19T20:09:03.000Z","published_at":"2012-06-02T00:17:41.000Z","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\u003eFind the Built-In functions and Toolbox functions in either a string or a function handle.\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\u003eGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\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:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eInputs:\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\u003efh=@(x)log10(x)+log2(x)+abs(x)\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\u003estr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\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:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eOutputs:\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\u003e'abs log2 log10'\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\u003e'abs filter numel sin filter2 smooth3'\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\u003eRelated to \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=\\\"http://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eCody_464\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\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":733,"title":"Extract Built In Functions and Toolbox Functions from String or Function Handle","description":"Find the Built-In functions and Toolbox functions in either a string or a function handle.\r\n\r\nGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\r\n\r\n*Inputs:*\r\n\r\nfh=@(x)log10(x)+log2(x)+abs(x)\r\n\r\nstr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\r\n\r\n*Outputs:*\r\n\r\n'abs log2 log10'\r\n\r\n'abs filter numel sin filter2 smooth3'\r\n\r\nRelated to \r\n\u003chttp://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer Cody_464\u003e","description_html":"\u003cp\u003eFind the Built-In functions and Toolbox functions in either a string or a function handle.\u003c/p\u003e\u003cp\u003eGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\u003c/p\u003e\u003cp\u003e\u003cb\u003eInputs:\u003c/b\u003e\u003c/p\u003e\u003cp\u003efh=@(x)log10(x)+log2(x)+abs(x)\u003c/p\u003e\u003cp\u003estr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutputs:\u003c/b\u003e\u003c/p\u003e\u003cp\u003e'abs log2 log10'\u003c/p\u003e\u003cp\u003e'abs filter numel sin filter2 smooth3'\u003c/p\u003e\u003cp\u003eRelated to  \u003ca href=\"http://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer\"\u003eCody_464\u003c/a\u003e\u003c/p\u003e","function_template":"function functions = find_functions(fh_str)\r\n  functions = '';\r\nend","test_suite":"%%\r\nfh_str='log2(x)+smooth3(x,y)+abs(2)+log10(5)';\r\nexp_str='abs log10 log2 smooth3';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='for k=log10(x):log2(x)+abs(x)';\r\nexp_str='abs for log10 log2';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str=@(x)x^2+sin(x)-cos(x);\r\nexp_str='cos sin';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='@(x)x^2+sin(x)-cos(x)';\r\nexp_str='cos sin';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='filter2(x,A)+filter(x)-cos(x) expm(z)';\r\nexp_str='cos filter expm filter2';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n%%\r\nfh_str='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)';\r\nexp_str='abs filter numel sin filter2 smooth3';\r\nassert(isequal(find_functions(fh_str),exp_str))\r\n","published":true,"deleted":false,"likes_count":5,"comments_count":6,"created_by":3097,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":84,"test_suite_updated_at":"2012-07-18T13:18:16.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2012-06-01T23:09:01.000Z","updated_at":"2026-05-19T20:09:03.000Z","published_at":"2012-06-02T00:17:41.000Z","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\u003eFind the Built-In functions and Toolbox functions in either a string or a function handle.\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\u003eGenerate a string of alphabetized Built-In functions followed by alphabetized Functions.\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:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eInputs:\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\u003efh=@(x)log10(x)+log2(x)+abs(x)\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\u003estr='smooth3(x,y)-filter(x)+abs(n)+filter2(u)+sin(x)+numel(z)'\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:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003eOutputs:\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\u003e'abs log2 log10'\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\u003e'abs filter numel sin filter2 smooth3'\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\u003eRelated to \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=\\\"http://www.mathworks.com/matlabcentral/cody/problems/464-function-sniffer\\\"\u003e\u003cw:r\u003e\u003cw:t\u003eCody_464\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\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":"Back to Alphabet","count":1,"selected":false},{"value":"Handling Functions","count":1,"selected":false}],[{"value":"hard","count":1,"selected":false}]],"term":"tag:\"isa\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}