Welsh, D.J.A. and Powell, M.B. (1967) An Upper Bound for the Chromatic Number of a Graph and Its Application to Timetabling Problems. 《The Computer Journal》, 10, 85-86. 《The Computer Journal》 1 图着色算法概述
1967年,Welsh和Powell算法引入了…
矩阵变元素,变列向量 W1(Z1 < Z2) nan; % Z1,Z2 all matrix,Only plot points where Z1 > Z2;Z1 < Z2位置值填为NaNx x(:); % Now x is a 30-by-1 vector; matrix变列vector技巧3D表面图 hand figure; % Handle to the figure, for more plotting later…
rank() over, dense_rank() over, row_number() over的区别
--ROW_NUMBER() OVER 不需要考虑并列,即使查询出来的数值相同也会进行连续排名
SELECT NAME, STUNO, SUBJECT, SCORE, ROW_NUMBER() OVER(PARTITION BY SUBJECT ORDER BY SCORE DESC) TO_RANK FROM SCOTT…