这个Matlab程序实现最速下降算法。最速下降法是一种最基本的算法，它在最优化方法中占有重要地位.最速下降法的优点是工作量小，存储变量较少,初始点要求不高；缺点是收敛慢，最速下降法适用于寻优过程的前期迭代或作为间插步骤，当接近极值点时，宜选用别种收敛快的算法.
-Matlab implementation of this procedure steepest descent algorithm.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001086s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.097836s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.000910s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001113s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000982s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003196s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000940s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003865s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.021312s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001058s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 31926 [ RunTime:0.020701s ]
