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¦b MATLAB ¹Bºâ¹Lµ{¡A¥i¥HÀH®É§ïÅܨC¤@­Ó¯x°}ªººû«×¡A¥H®e¯Ç·sªº¸ê®Æ¡C¦ý¬O¨C¤@¦¸¼W¤j¯x°}ªº®e¶q®É¡AMATLAB´N¥²¶·­n¦V¹q¸£ªº§@·~¨t²Î¯Á¨ú°O¾ÐÅé¡A¦]¦¹·|³y¦¨µ{¦¡°õ¦æ®Ä²vªº­°§C¡A¦Ó¥B³y¦¨°O¾ÐÅé¨Ï¥Îªº¤À´²²{¶H¡]Memory Segmentation¡^¡A¦¹ºØ¥Ñ©ó°O¾ÐÅ骺°ÊºA°t¸m¦Ó³y¦¨ªº¤À´²¨Ï¥Î²{¶H¡A¥i¯à¾É­P¡u¹ê»ÚÁö¤´¦³¥R¨¬ªº°O¾ÐÅé¡A¦ý«o¥¼¦³³sÄòªÅ¶¡¥H³B²z¸û¤j¯x°}¡vªº²{¶H¡C

°ò©ó¥H¤WºØºØ­ì¦]¡A­Y¹w¥ýª¾¹D¨Ï¥Î¯x°}ªººû«×¤j¤p¡A«h³Ì¦n¹ê¬I¯x°}ªº¹w¥ý°t¸m¡]Pre-allocation¡^¡A¥i¥Îªº«ü¥O¦³ zeros¡Bones¡Bcell¡]¥Î©ó²§­È°}¦Cªº¹w¥ý°t¸m¡^¤Î struct¡]¥Î©óµ²ºc°}¦Cªº¹w¥ý°t¸m¡^µ¥¡C¨Ò¦p¡A±ý­pºâ¯x°} x ªº¨C¤@­Ó¤¸¯Àªº¥­¤è­È¨Ã±N¤§Àx¦s©ó¯x°} y¡A¦³¨âºØ§@ªk¡A¦p¤U¡G

Example 1: 02-µ{¦¡½X»P°O¾ÐÅ餧³Ì¨Î¤Æ/preAllocate01.mn = 1000000; clear y1; % ²M°£ÅÜ¼Æ y1 tic for i = 1:n y1(i) = i^2; end time1=toc; y2 = zeros(1, n); % ¹w¥ý°t¸m©Ò¶·¯x°} y2 tic for i = 1:n y2(i) = i^2; end time2=toc; fprintf('time1 = %g, time2 = %g, time1/time2 = %g\n', time1, time2, time1/time2);time1 = 0.248923, time2 = 0.00902574, time1/time2 = 27.5793

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