{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-04-16T00:12:35.000Z","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":"2026-04-16T00:00:00.000Z","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":24,"title":"Function Iterator","description":"Given a handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u003e= 1, return a  handle fh2 to a function which applies the given function n times.\n\nExamples:\n\n \u003e\u003e addOne = @(x)x+1;\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\n \u003e\u003e addTen(3)\n ans =\n     13\n\n \u003e\u003e squarer = @(a) a^2;\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\n \u003e\u003e fh2(3)\n ans =\n         6561\n\n % Golden Ratio\n \u003e\u003e fh = @(y)sqrt(y+1);\n \u003e\u003e fh2 = iterate_fcn(fh,30);\n \u003e\u003e fh2(1)\n ans =\n     1.6180\n","description_html":"\u003cp\u003eGiven a handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u003e= 1, return a  handle fh2 to a function which applies the given function n times.\u003c/p\u003e\u003cp\u003eExamples:\u003c/p\u003e\u003cpre\u003e \u003e\u003e addOne = @(x)x+1;\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\n \u003e\u003e addTen(3)\n ans =\n     13\u003c/pre\u003e\u003cpre\u003e \u003e\u003e squarer = @(a) a^2;\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\n \u003e\u003e fh2(3)\n ans =\n         6561\u003c/pre\u003e\u003cpre\u003e % Golden Ratio\n \u003e\u003e fh = @(y)sqrt(y+1);\n \u003e\u003e fh2 = iterate_fcn(fh,30);\n \u003e\u003e fh2(1)\n ans =\n     1.6180\u003c/pre\u003e","function_template":"function fh2 = iterate_fcn(fh, n)\nfh2 = fh;\nend","test_suite":"%%\nnoOp = @(x)x;\nfh2 = iterate_fcn(noOp, 50);\nassert(isequal(fh2(pi),pi));\n\n\n%%\naddOne = @(x)x+1;\naddTen = iterate_fcn(addOne, 10);\nassert(isequal(addTen(3),13));\n\n%%\naddOne = @(x)x+1;\naddOne2 = iterate_fcn(addOne, 1);\nassert(isequal(addOne2(3),4));\n\n%%\nsquarer = @(a) a^2;\nfh2 = iterate_fcn(squarer, 3);\nassert(isequal(fh2(3),6561));\n\n%%\nfh = @(y)sqrt(y+1);\nfh2 = iterate_fcn(fh,30);\nassert(abs(fh2(1) - (1+sqrt(5))/2) \u003c 100*eps);","published":true,"deleted":false,"likes_count":61,"comments_count":27,"created_by":1,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":2245,"test_suite_updated_at":"2012-01-18T01:00:20.000Z","rescore_all_solutions":false,"group_id":2,"created_at":"2012-01-18T01:00:20.000Z","updated_at":"2026-04-08T14:15:06.000Z","published_at":"2012-01-18T01:00:20.000Z","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 handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u0026gt;= 1, return a handle fh2 to a function which applies the given function n times.\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\u003eExamples:\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 addOne = @(x)x+1;\\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\\n \u003e\u003e addTen(3)\\n ans =\\n     13\\n\\n \u003e\u003e squarer = @(a) a^2;\\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\\n \u003e\u003e fh2(3)\\n ans =\\n         6561\\n\\n % Golden Ratio\\n \u003e\u003e fh = @(y)sqrt(y+1);\\n \u003e\u003e fh2 = iterate_fcn(fh,30);\\n \u003e\u003e fh2(1)\\n ans =\\n     1.6180]]\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":{"errors":[],"problems":[{"id":24,"title":"Function Iterator","description":"Given a handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u003e= 1, return a  handle fh2 to a function which applies the given function n times.\n\nExamples:\n\n \u003e\u003e addOne = @(x)x+1;\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\n \u003e\u003e addTen(3)\n ans =\n     13\n\n \u003e\u003e squarer = @(a) a^2;\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\n \u003e\u003e fh2(3)\n ans =\n         6561\n\n % Golden Ratio\n \u003e\u003e fh = @(y)sqrt(y+1);\n \u003e\u003e fh2 = iterate_fcn(fh,30);\n \u003e\u003e fh2(1)\n ans =\n     1.6180\n","description_html":"\u003cp\u003eGiven a handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u003e= 1, return a  handle fh2 to a function which applies the given function n times.\u003c/p\u003e\u003cp\u003eExamples:\u003c/p\u003e\u003cpre\u003e \u003e\u003e addOne = @(x)x+1;\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\n \u003e\u003e addTen(3)\n ans =\n     13\u003c/pre\u003e\u003cpre\u003e \u003e\u003e squarer = @(a) a^2;\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\n \u003e\u003e fh2(3)\n ans =\n         6561\u003c/pre\u003e\u003cpre\u003e % Golden Ratio\n \u003e\u003e fh = @(y)sqrt(y+1);\n \u003e\u003e fh2 = iterate_fcn(fh,30);\n \u003e\u003e fh2(1)\n ans =\n     1.6180\u003c/pre\u003e","function_template":"function fh2 = iterate_fcn(fh, n)\nfh2 = fh;\nend","test_suite":"%%\nnoOp = @(x)x;\nfh2 = iterate_fcn(noOp, 50);\nassert(isequal(fh2(pi),pi));\n\n\n%%\naddOne = @(x)x+1;\naddTen = iterate_fcn(addOne, 10);\nassert(isequal(addTen(3),13));\n\n%%\naddOne = @(x)x+1;\naddOne2 = iterate_fcn(addOne, 1);\nassert(isequal(addOne2(3),4));\n\n%%\nsquarer = @(a) a^2;\nfh2 = iterate_fcn(squarer, 3);\nassert(isequal(fh2(3),6561));\n\n%%\nfh = @(y)sqrt(y+1);\nfh2 = iterate_fcn(fh,30);\nassert(abs(fh2(1) - (1+sqrt(5))/2) \u003c 100*eps);","published":true,"deleted":false,"likes_count":61,"comments_count":27,"created_by":1,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":2245,"test_suite_updated_at":"2012-01-18T01:00:20.000Z","rescore_all_solutions":false,"group_id":2,"created_at":"2012-01-18T01:00:20.000Z","updated_at":"2026-04-08T14:15:06.000Z","published_at":"2012-01-18T01:00:20.000Z","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 handle fh to a function which takes a scalar input and returns a scalar output and an integer n \u0026gt;= 1, return a handle fh2 to a function which applies the given function n times.\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\u003eExamples:\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 addOne = @(x)x+1;\\n \u003e\u003e addTen = iterate_fcn(addOne, 10);\\n \u003e\u003e addTen(3)\\n ans =\\n     13\\n\\n \u003e\u003e squarer = @(a) a^2;\\n \u003e\u003e fh2 = iterate_fcn(squarer, 3);\\n \u003e\u003e fh2(3)\\n ans =\\n         6561\\n\\n % Golden Ratio\\n \u003e\u003e fh = @(y)sqrt(y+1);\\n \u003e\u003e fh2 = iterate_fcn(fh,30);\\n \u003e\u003e fh2(1)\\n ans =\\n     1.6180]]\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\"}]}"}],"term":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\"","current_player_id":null,"fields":[{"name":"page","type":"integer","callback":null,"default":1,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"per_page","type":"integer","callback":null,"default":50,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"sort","type":"string","callback":null,"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":null,"prepend":true},{"name":"body","type":"text","callback":null,"default":"*:*","directive":null,"facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":false},{"name":"group","type":"string","callback":null,"default":null,"directive":"group","facet":true,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"difficulty_rating_bin","type":"string","callback":null,"default":null,"directive":"difficulty_rating_bin","facet":true,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"id","type":"integer","callback":null,"default":null,"directive":"id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"tag","type":"string","callback":null,"default":null,"directive":"tag","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"product","type":"string","callback":null,"default":null,"directive":"product","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"created_at","type":"timeframe","callback":{},"default":null,"directive":"created_at","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"profile_id","type":"integer","callback":null,"default":null,"directive":"author_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"created_by","type":"string","callback":null,"default":null,"directive":"author","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"player_id","type":"integer","callback":null,"default":null,"directive":"solver_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"player","type":"string","callback":null,"default":null,"directive":"solver","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"solvers_count","type":"integer","callback":null,"default":null,"directive":"solvers_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"comments_count","type":"integer","callback":null,"default":null,"directive":"comments_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"likes_count","type":"integer","callback":null,"default":null,"directive":"likes_count","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"leader_id","type":"integer","callback":null,"default":null,"directive":"leader_id","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true},{"name":"leading_solution","type":"integer","callback":null,"default":null,"directive":"leading_solution","facet":null,"facet_method":"and","operator":null,"param":"term","static":null,"prepend":true}],"filters":[{"name":"asset_type","type":"string","callback":null,"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":null,"static":"\"cody:problem\"","prepend":true},{"name":"profile_id","type":"integer","callback":{},"default":null,"directive":null,"facet":null,"facet_method":"and","operator":null,"param":"author_id","static":null,"prepend":true}],"query":{"params":{"per_page":50,"term":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\"","current_player":null,"sort":"map(difficulty_value,0,0,999) asc"},"parser":"MathWorks::Search::Solr::QueryParser","directives":{"term":{"directives":{"group":[["group:\"Handling Functions\"","","\"","Handling Functions","\""],["group:\"Cody Challenge\"","","\"","Cody Challenge","\""]],"difficulty_rating_bin":[["difficulty_rating_bin:medium","","","medium",""]]}}},"facets":{"#\u003cMathWorks::Search::Field:0x00007f17c2664578\u003e":["Handling Functions","Cody Challenge"],"#\u003cMathWorks::Search::Field:0x00007f17c26644d8\u003e":["medium"]},"filters":{"#\u003cMathWorks::Search::Field:0x00007f17c2663c18\u003e":"\"cody:problem\""},"fields":{"#\u003cMathWorks::Search::Field:0x00007f17c26647f8\u003e":1,"#\u003cMathWorks::Search::Field:0x00007f17c2664758\u003e":50,"#\u003cMathWorks::Search::Field:0x00007f17c26646b8\u003e":"map(difficulty_value,0,0,999) asc","#\u003cMathWorks::Search::Field:0x00007f17c2664618\u003e":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\""},"user_query":{"#\u003cMathWorks::Search::Field:0x00007f17c2664618\u003e":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\""},"queried_facets":{"#\u003cMathWorks::Search::Field:0x00007f17c2664578\u003e":["Handling Functions","Cody Challenge"],"#\u003cMathWorks::Search::Field:0x00007f17c26644d8\u003e":["medium"]}},"query_backend":{"connection":{"configuration":{"index_url":"http://index-op-v2/solr/","query_url":"http://search-op-v2/solr/","direct_access_index_urls":["http://index-op-v2/solr/"],"direct_access_query_urls":["http://search-op-v2/solr/"],"timeout":10,"vhost":"search","exchange":"search.topic","heartbeat":30,"pre_index_mode":false,"host":"rabbitmq-eks","port":5672,"username":"cody-search","password":"78X075ddcV44","virtual_host":"search","indexer":"amqp","http_logging":"true","core":"cody"},"query_connection":{"uri":"http://search-op-v2/solr/cody/","proxy":null,"connection":{"parallel_manager":null,"headers":{"User-Agent":"Faraday v1.0.1"},"params":{},"options":{"params_encoder":"Faraday::FlatParamsEncoder","proxy":null,"bind":null,"timeout":null,"open_timeout":null,"read_timeout":null,"write_timeout":null,"boundary":null,"oauth":null,"context":null,"on_data":null},"ssl":{"verify":true,"ca_file":null,"ca_path":null,"verify_mode":null,"cert_store":null,"client_cert":null,"client_key":null,"certificate":null,"private_key":null,"verify_depth":null,"version":null,"min_version":null,"max_version":null},"default_parallel_manager":null,"builder":{"adapter":{"name":"Faraday::Adapter::NetHttp","args":[],"block":null},"handlers":[{"name":"Faraday::Response::RaiseError","args":[],"block":null}],"app":{"app":{"ssl_cert_store":{"verify_callback":null,"error":null,"error_string":null,"chain":null,"time":null},"app":{},"connection_options":{},"config_block":null}}},"url_prefix":"http://search-op-v2/solr/cody/","manual_proxy":false,"proxy":null},"update_format":"RSolr::JSON::Generator","update_path":"update","options":{"url":"http://search-op-v2/solr/cody"}}},"query":{"params":{"per_page":50,"term":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\"","current_player":null,"sort":"map(difficulty_value,0,0,999) asc"},"parser":"MathWorks::Search::Solr::QueryParser","directives":{"term":{"directives":{"group":[["group:\"Handling Functions\"","","\"","Handling Functions","\""],["group:\"Cody Challenge\"","","\"","Cody Challenge","\""]],"difficulty_rating_bin":[["difficulty_rating_bin:medium","","","medium",""]]}}},"facets":{"#\u003cMathWorks::Search::Field:0x00007f17c2664578\u003e":["Handling Functions","Cody Challenge"],"#\u003cMathWorks::Search::Field:0x00007f17c26644d8\u003e":["medium"]},"filters":{"#\u003cMathWorks::Search::Field:0x00007f17c2663c18\u003e":"\"cody:problem\""},"fields":{"#\u003cMathWorks::Search::Field:0x00007f17c26647f8\u003e":1,"#\u003cMathWorks::Search::Field:0x00007f17c2664758\u003e":50,"#\u003cMathWorks::Search::Field:0x00007f17c26646b8\u003e":"map(difficulty_value,0,0,999) asc","#\u003cMathWorks::Search::Field:0x00007f17c2664618\u003e":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\""},"user_query":{"#\u003cMathWorks::Search::Field:0x00007f17c2664618\u003e":"group:\"Handling Functions\" difficulty_rating_bin:medium group:\"Cody Challenge\""},"queried_facets":{"#\u003cMathWorks::Search::Field:0x00007f17c2664578\u003e":["Handling Functions","Cody Challenge"],"#\u003cMathWorks::Search::Field:0x00007f17c26644d8\u003e":["medium"]}},"options":{"fields":["id","difficulty_rating"]},"join":" "},"results":[{"id":24,"difficulty_rating":"medium"}]}}