K杩戦偦绠楁硶1.浠€涔堟槸k杩戦偦绠楁硶锛熷鏋滃ぇ澶氭暟瀹炰緥灞炰簬鏌愪釜绫伙紝鍒欏皢杈撳叆瀹炰緥褰掑叆姝ょ被銆傚涓嬪浘鎵€绀猴細杈撳叆涓€涓柊鐨勨潛鐐癸紝鍒ゆ柇鏄睘浜巆lassA杩樻槸classB銆傞偅涔堥棶棰樺氨鏉ヤ簡k杩戦偦绠楁硶銆傚浣曞垽鏂渶杩戦偦锛熻绠楄窛绂伙紒濡備綍璁＄畻璺濈2锛岃窛绂绘祴搴?锛屾姘忚窛绂?$d(x,y)=\sqrt{\displaystyle\sum_{i=1}^{n}(y_i-x_i)^2}$$3锛屾浖鍝堥】璺濈$$d(x,y)=(\displaystyle\sum_{i=0}^{n}{|y_i-x_i|})$$4,闂靛彲澶柉鍩鸿窛绂?$闂靛彲澶柉鍩鸿窛绂?(\displaystyle\sum_{i=0}^{n}{|y_i-x_i|})^\frac{1}{p}$$鐜板湪鎴戜滑鐭ラ亾濡備綍纭畾璺濈浜嗭紝浣嗘槸闂鍙堟潵浜嗭紝鎴戜滑搴旇濡備綍瀹氫箟鎴戜滑鐨凨鍊煎憿锛?銆乲鍊肩殑閫夋嫨濡傛灉閫夋嫨杈冨皬鐨刱鍊硷紝鐩稿綋浜庝娇鐢ㄨ緝灏忛偦鍩熷唴鐨勮缁冩牱渚嬭繘琛岄娴嬶紝鈥滃涔犫€濈殑閫艰繎璇樊浼氬噺灏忋€傦紙鐩镐技锛夎缁冩牱渚嬩細瀵归娴嬬粨鏋滀骇鐢熷奖鍝嶃€備絾缂虹偣鏄€滃涔犫€濈殑浼拌璇樊浼氬澶э紝棰勬祴缁撴灉瀵归偦灞呯殑瀹炰緥鐐归潪甯告晱鎰熴€傚鏋滅浉閭诲疄渚嬬偣鎭板ソ鏄櫔澹帮紝鍒欓娴嬪皢鏄敊璇殑銆備篃灏辨槸璇达紝k鍊肩殑闄嶄綆鎰忓懗鐫€鏁翠綋妯″瀷鍙樺緱澶嶆潅锛屽鏄撳嚭鐜拌繃鎷熷悎銆傞€夋嫨杈冨ぇ鐨刱鍊肩浉褰撲簬浣跨敤杈冨ぇ閭诲煙涓殑璁粌瀹炰緥杩涜棰勬祴銆傚畠鐨勪紭鐐规槸鍙互鍑忓皯瀛︿範鐨勪及璁¤宸紝缂虹偣鏄細澧炲姞瀛︿範鐨勮繎浼艰宸€傝繖鏃讹紝涓庤緭鍏ュ疄渚嬬浉璺濊緝杩滐紙涓嶇浉浼硷級鐨勮缁冨疄渚嬩篃浼氬棰勬祴浜х敓褰卞搷锛岄€犳垚棰勬祴閿欒銆俴鍊肩殑澧炲姞鎰忓懗鐫€鏁翠釜妯″瀷鍙樺緱鏇寸畝鍗曘€傚鏋渒=N锛岄偅涔堟棤璁鸿緭鍏ュ疄渚嬫槸浠€涔堬紝瀹冮兘灏嗚绠€鍗曞湴棰勬祴涓哄睘浜庤缁冨疄渚嬩腑浠ｈ〃鏈€澶氱殑绫诲埆銆傛鏃舵ā鍨嬭繃浜庣畝鍗曪紝瀹屽叏蹇界暐浜嗚缁冩牱渚嬩腑鐨勫ぇ閲忔湁鐢ㄤ俊鎭紝杩欐槸涓嶅彲鍙栫殑銆傚湪搴旂敤涓紝k鐨勫彇鍊间竴鑸彇杈冨皬鐨勫€笺€傞€氬父锛屼氦鍙夐獙璇佹柟娉曠敤浜庨€夋嫨鏈€浼榢鍊笺€傚洓銆佺畻娉曡繃绋嬶紙python锛夌涓€姝ワ細纭畾KNN绠楁硶闇€瑕佺‘瀹氱殑鍙傛暟锛?銆佽緭鍏ュ緟鍒嗙被鍙橀噺锛堣缁冮泦锛夛紱2銆並鍊硷紱3.璺濈鐨勮绠楁柟娉曪紱4.璁粌闆嗘暟鎹紱4.銆佽缁冮泦鏍囩鐨勭浜屾锛氳绠楄窛绂伙紝KNN绠楁硶鐨勬牳蹇冩槸璁＄畻姣忎釜鍙橀噺鐨勮窛绂伙紝鐒跺悗閫夋嫨鏈€鍓嶉潰鐨凨涓€傛墍浠ユ垜浠湁鏃跺€欓渶瑕佸杈撳叆鏁版嵁杩涜鎵╃淮浣垮叾涓庢祴璇曢泦鐨勫舰鐘剁浉鍚屻€傛楠?锛氬垽鏂璌NN鐨勫噯纭€?.KNN璇勪及浼樺娍鏄撲簬瀹炴柦锛氶壌浜庣畻娉曠殑绠€鍗曟€у拰鍑嗙‘鎬э紝瀹冩槸鏂版暟鎹瀛﹀灏嗗涔犵殑绗竴鎵瑰垎绫诲櫒涔嬩竴閫傚簲鎬э細闅忕潃鏂拌缁冩牱鏈殑澧炲姞锛岀畻娉曢€傚簲浠讳綍鏂版暟鎹紝鍥犱负鎵€鏈夎缁冩暟鎹兘瀛樺偍鍦ㄥ唴瀛樹腑寰堝皯鐨勮秴鍙傛暟锛欿NN鍙渶瑕乲鍊煎拰璺濈搴﹂噺锛屼笌鍏朵粬鏈哄櫒瀛︿範绠楁硶鐩告瘮闇€瑕佸緢灏戠殑瓒呭弬鏁扮己鐐逛笉鑳藉緢濂藉湴鎵╁睍锛氱敱浜嶬NN鏄竴绉嶆儼鎬х畻娉曪紝瀹冩瘮鍏朵粬鍒嗙被鍣ㄤ娇鐢ㄦ洿澶氱殑鍐呭瓨鍜屾暟鎹瓨鍌ㄣ€備粠鏃堕棿鍜岄噾閽辩殑瑙掑害鏉ョ湅锛岃繖鍙兘鏄槀璐电殑銆傛洿澶氱殑鍐呭瓨鍜屽瓨鍌ㄤ細澧炲姞涓氬姟寮€鏀紝鏇村鐨勬暟鎹彲鑳介渶瑕佹洿闀跨殑鏃堕棿鏉ヨ绠椼€傚敖绠″凡缁忓垱寤轰簡涓嶅悓鐨勬暟鎹粨鏋勶紙渚嬪Ball-Tree锛夋潵瑙ｅ喅璁＄畻鏁堢巼浣庝笅鐨勯棶棰橈紝浣嗗垎绫诲櫒鏄惁鐞嗘兂鍙兘鍙栧喅浜庝笟鍔￠棶棰樼殑缁存暟鐏鹃毦锛欿NN绠楁硶瀹规槗鎴愪负curseofdimensionality锛岃繖鎰忓懗鐫€瀹冨湪楂樼淮鏁版嵁杈撳叆涓婅〃鐜颁笉浣炽€傝繖鏈夋椂琚О涓哄嘲鍖栫幇璞★紝鍦ㄧ畻娉曡揪鍒版渶浣崇壒寰佹暟閲忓悗锛岄澶栫殑鐗瑰緛浼氬鍔犲垎绫婚敊璇殑鏁伴噺锛岀壒鍒槸褰撴牱鏈噺杈冨皬鏃讹紝寰堝鏄撹繃鎷熷悎锛氱敱浜庘€滅淮鏁扮伨闅锯€?锛孠NN涔熸洿瀹规槗杩囨嫙鍚堛€傝櫧鐒朵娇鐢ㄤ簡鐗瑰緛閫夋嫨鍜岄檷缁存妧鏈潵闃叉杩欑鎯呭喌鐨勫彂鐢熷叚銆乸ython浠ｇ爜瀹炵幇锛堟墜鍐欏瓧浣撹瘑鍒級闇€瑕佽皟鐢ㄥ寘锛堝彲浠ュ皾璇曚娇鐢╬ytorch鎻愰珮璁＄畻閫熷害锛屽師鐞嗕篃寰堢畝鍗昿ytorch鍙互涓巒umpy鍑犱箮鏃犵紳瀵规帴)importtorchimportnumpyasnpiportoperatorfromosimportlistdir鏍稿績浠ｇ爜defKNN(inx,dataset,labels,k,distances_way):"""inx:杈撳叆寰呭垎绫绘暟datset:杈撳叆鏍锋湰璁粌闆嗘爣绛?labelvectork:閫夋嫨鏈€杩戠殑閭诲眳涓暟锛屽叾涓璴abel涓暟涓庣煩闃礵ataset鐨勮鏁扮浉鍚宒istance:璁＄畻璺濈鐨勬柟寮?""#calculatethedistancedatasize_h=dataset.shape[0]inx=np.tile(inx,(datasize_h,1))#灏唅nx缁村害灞曞紑涓轰笌鏁版嵁闆嗗舰鐘剁浉鍚岀殑鐭╅樀ifdistances_way==str('o'):#娆ф皬璺濈diffmat=inx-鏁版嵁闆唖q_diffmat=diffmat**2sq_distances=sq_diffmat.sum(axis=1)distance=sq_distances**0.5elifdistances_way==str('man'):#鏇煎搱椤胯窛绂籨iffmat=inx-鏁版嵁闆哸bs_diffmat=abs(diffmat)distance=abs_diffmat.sum(axis=1)elifdistances_way==str('min'):#Minkowskidistancep=int(input('inputpvalue:'))diffmat=inx-datasetsq_diffmat=diffmat**2sq_distances=sq_diffmat.sum(axis=1)distance=sq_distances**(1/p)distance_sort=distance.argsort()#鎸夌収璺濈浠庡皬鍒板ぇ鎺掑簭#returndistance_sort#灏嗘帓搴忓悗鐨勮窛绂诲搴斿埌鎴戜滑鐨刲abel涓婏紝浣跨敤鍝堝笇琛╠ic={}foriinrange(k):diff_label=labels[distance_sort[i]]dic[diff_label]=dic.get(diff_label,0)+1dic_sort=sorted(dic.items(),key=operator.itemgetter(1),reverse=True)returndic_sort[0][0]鎵嬪啓瀛椾綋璇嗗埆锛堝垪瀛愭潵鑷€婃満鍣ㄥ涔犲疄鎴樸€嬶紝鑷繁鍋氫簡涓€浜涙敼鍔級#灏?2*32杞寲涓?*1024鐨勭煩闃碉紝涔熷彲浠ヨ浆鍖栧彉鎴愪竴涓?2*32鐨勭煩闃礵efdata_read(path):data=open(path)data_use=np.zeros((1,1024))foriinrange(32):data_line=data.readline()#璇诲彇姣忎竴琛宖orjinrange(32):data_use[0,32*i+j]=int(data_line[j])returndata_use#Convertthe32*32textfileintoa32*32matrix#defdata_read(path):#data=open(path)#data_use=np.zeros([32,32])#data_narry=np.array(data)#forjinrange(len(a)):#foriinrange(len(a)):#data_use[i][j]=a[i][j]#returndata_usedefhandwritingClassTest():"""hwLabels:鎵嬪啓鏁板瓧鐨勭湡瀹炲€糾:璁粌闆嗙殑鏂囦欢鏁癿Tset:娴嬭瘯闆嗙殑鏂囦欢鏁皌rainingMat:瀛樺偍璁粌闆嗙殑鎵€鏈変竴缁存暟鎹?""hwLabels=[]trainingFileList=listdir('D:/Github-code/python-gogogo/鏈哄櫒瀛︿範/鍒嗙被闂/K杩戦偦绠楁硶/鎵嬪啓鏁版嵁鏂囦欢/training_handwriting')m=len(trainingFileList)#m=1934trainingMat=np.zeros((m,1024))foriinrange(m):#鎷嗗垎鏂囦欢鍚?-->寮€濮嬪彧鍙栨枃浠跺悕鐨勭涓€涓瓧绗︼紙瀵瑰簲瀹炴暟锛塮ileNameStr=trainingFileList[i]#鑾峰彇鎵€鏈夋枃浠跺悕StringfileStr=fileNameStr.split('.')[0]classNumStr=int(fileStr.split('_')[0])hwLabels.append(classNumStr)#鎷嗗垎鏂囦欢鍚?-->endtrainingMat[i,:]=data_read('D:/Github-code/python-gogogo/鏈哄櫒瀛︿範/鍒嗙被闂/K杩戦偦绠楁硶/鎵嬪啓鏁版嵁鏂囦欢/training_handwriting/%s'%fileNameStr)#returntrainingMattestFileList=listdir('D:/Github-code/python-gogogo/鏈哄櫒瀛︿範/鍒嗙被闂/K杩戦偦绠楁硶/鎵嬪啓鏁版嵁鏂囦欢/test_handwriting')errorCount=0.0mTest=len(testFileList)fori鍦ㄨ寖鍥村唴锛坢Test锛夛細fileNameStr=testFileList[i]fileStr=fileNameStr.split('.')[0]classNumStr=int(fileStr.split('_')[0])vectorUnderTest=data_read('D:/Github-code/python-gogogo/鏈哄櫒瀛︿範/鍒嗙被闂/K杩戦偦绠楁硶/鎵嬪啓鏁版嵁鏂囦欢/test_handwriting/%s'%fileNameStr)print(vectorUnderTest.shape)classifierResult=KNN(vectorUnderTest,trainingMat,hwLabels,3,'o')print("KNN鍒嗙被缁撴灉锛?d锛屽疄闄呯粨鏋滐細%d"%(classifierResult,classNumStr))if(classifierResult!=classNumStr):errorCount+=1.0print("\n閿欒鏁颁釜鏁帮細%d"%errorCount)print("\n閿欒鐜囷細%f"%(errorCount/float(mTest)))7.涓汉鎬濊€冩棦鐒惰繃绋嬩腑娑夊強鍒皃ytorch锛岃€屾垜浠仛鐨勬槸鈥滄墜鍐欏瓧浣撹瘑鍒€濓紝閭ｄ箞涓嶅Θ灏濊瘯浣跨敤涓€涓嬭嚜宸辨媿涓€寮犵収鐗囷紝鐒跺悗璇嗗埆鑷繁鐨勬墜鍐欏瓧浣擄紙鍥剧墖浜屽€煎寲锛屾垜鏆傛椂鎯冲埌杩欎釜锛屽洜涓烘繁搴﹀涔犳湰韬笉鏄お鎳傦級锛屽鏋渆鐢ㄧ殑鏄疜NN绠楁硶锛屾晥鐜囧彲鑳芥病鏈塁NN绠楁硶楂橈紝杩欓噷闈㈠彲鑳借繕娑夊強鍒颁簡opencv搴撶殑浣跨敤濡傛灉澶у鍦ㄨ瘎璁哄尯鏈変粈涔堟兂娉曪紝杩樹笉濡傝涪鎴戝搱鍝堝搱鍝堛€傪煒€馃榾鏂囩珷鏈変笉瓒充箣澶勮鐣欒█銆傚弬鑰?.https://www.ibm.com/cn-zh/topics/knn#:~:text=k%2D%E6%9C%80%E8...,%E6%9C%80%E5%B8%B8%E8%A1%A8%E7%A4%BA%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