{"id":243,"date":"2014-09-04T06:40:29","date_gmt":"2014-09-03T21:40:29","guid":{"rendered":"https:\/\/www.dogrow.net\/python\/?p=243"},"modified":"2019-10-29T09:23:52","modified_gmt":"2019-10-29T00:23:52","slug":"blog57","status":"publish","type":"post","link":"https:\/\/www.dogrow.net\/python\/blog57\/","title":{"rendered":"(57) numpy\u3067\u5185\u7a4d"},"content":{"rendered":"

\u4ee5\u4e0b\u306e\u306a\u3059\u89d245\u5ea6\u306e\u4e8c\u3064\u306e\u30d9\u30af\u30c8\u30eb\u306e\u5185\u7a4d\u3092\u6c42\u3081\u308b\u3002
\na = ( 3 , 3 )
\nb = ( 5 , 0 )<\/p>\n

\r\n>>> import numpy as np\r\n>>> a = np.array([3, 3])\r\n>>> a\r\narray([3, 3])\r\n>>> b = np.array([5, 0])\r\n>>> b\r\narray([5, 0])\r\n<\/pre>\n
numpy\u3067\u306f\u3001\u30d9\u30af\u30c8\u30eb\u306e\u5185\u7a4d\u3092 numpy.dot<\/span> \u3067\u6c42\u3081\u3089\u308c\u308b\u3002<\/p>\n
\r\n>>> np.dot(a, b)<\/span>\r\n15\r\n<\/span><\/pre>\n
\u691c\u7b97\u306e\u305f\u3081\u3001\u3053\u308c\u3092 |a||b|cos(\u0398)<\/span> \u3067\u6c42\u3081\u3066\u307f\u308b\u3002<\/p>\n
\r\n>>> da = np.linalg.norm(a)\r\n>>> da\r\n4.2426406871192848\r\n>>> db = np.linalg.norm(b)\r\n>>> db\r\n5.0\r\n>>> rad = np.pi * 45 \/ 180\r\n>>> rad\r\n0.7853981633974483\r\n>>>\r\n>>> da * db * np.cos(rad)\r\n14.999999999999998\r\n<\/span><\/pre>\n
\u3061\u306a\u307f\u306b numpy.linalg.norm<\/span> \u306f\u30d9\u30af\u30c8\u30eb\u9577\u3092\u6c42\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002<\/p>\n
\r\n>>> v = np.array((1,1))\r\n>>> np.linalg.norm(v)<\/span>\r\n1.4142135623730951\r\n<\/pre>\n
\u884c\u5217\u306e\u7a4d\u3082 numpy.dot<\/span> \u3067\u6c42\u3081\u3089\u308c\u308b\u3002<\/p>\n
\r\n>>> a=np.array([[1,2,3],[4,5,6]])\r\n>>> a\r\narray([[1, 2, 3],\r\n       [4, 5, 6]])\r\n>>> b=np.array([[1,3,5,7],[2,4,6,8],[4,5,6,7]])\r\n>>> b\r\narray([[1, 3, 5, 7],\r\n       [2, 4, 6, 8],\r\n       [4, 5, 6, 7]])\r\n>>> np.dot(a,b)\r\narray([[ 17,  26,  35,  44],\r\n       [ 38,  62,  86, 110]])\r\n<\/pre>\n
\n","protected":false},"excerpt":{"rendered":"
\u4ee5\u4e0b\u306e\u306a\u3059\u89d245\u5ea6\u306e\u4e8c\u3064\u306e\u30d9\u30af\u30c8\u30eb\u306e\u5185\u7a4d\u3092\u6c42\u3081\u308b\u3002 a = ( 3 , 3 ) b = ( 5 , 0 ) >>> import numpy as np >>> a = np.arra\u2026 \u7d9a\u304d\u3092\u8aad\u3080 »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-243","post","type-post","status-publish","format-standard","hentry","category-numpy"],"views":18011,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/posts\/243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/comments?post=243"}],"version-history":[{"count":14,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/posts\/243\/revisions"}],"predecessor-version":[{"id":2772,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/posts\/243\/revisions\/2772"}],"wp:attachment":[{"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/media?parent=243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/categories?post=243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dogrow.net\/python\/wp-json\/wp\/v2\/tags?post=243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}