see Spare Matrix wikipedia item, and scipy's documentation on different choices of sparse matrix type sparse matrix storage, only store non-zero entries. there're multiple possible data structures for this, and can be divided into 2 groups support ef…

最近在看<Spark for Data Science>这本书,阅读到<Machine Learning>这一节的时候被稀疏矩阵的存储格式CSC给弄的晕头转向的.所以专门写一篇文章记录一下我对这种格式的理解. 目的 Compressed Sparse Column Format (CSC)的目的是为了压缩矩阵,减少矩阵存储所占用的空间.这很好理解,手法无法就是通过增加一些"元信息"来描述矩阵中的非零元素存储的位置(基于列),然后结合非零元素的值来表示矩阵.这样在…

w https://en.wikipedia.org/wiki/Sparse_matrix 稀疏矩阵存储格式总结+存储效率对比:COO,CSR,DIA,ELL,HYB - Bin的专栏 - 博客园http://www.cnblogs.com/xbinworld/p/4273506.html 稀疏矩阵的存储格式(Sparse Matrix Storage Formats) - Donkey Vision - 博客频道 - CSDN.NEThttp://blog.csdn.net/anshan198…

题目: Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7, 0, 0 ], [ 0, 0, 0 ], [ 0, 0, 1 ] ] | 1 0 0 | | 7 0 0 | | 7 0 0 | AB =…

sparse matrix是用来存储大型稀疏矩阵用得,单细胞表达数据基本都用这个格式来存储,因为单细胞很大部分都是0,用普通文本矩阵存储太占空间. 使用也是相当简单: library("Matrix") readsCount <- read.csv("data/count.csv", header = T, row.names = 1) readsCountSM <- as(as.matrix(readsCount), "dgCMatrix&q…

Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: Input: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7, 0, 0 ], [ 0, 0, 0 ], [ 0, 0, 1 ] ] Output: | 1 0 0 | | 7 0 0 | | 7…

［抄题］: 给定两个 稀疏矩阵 A 和 B,返回AB的结果.您可以假设A的列数等于B的行数. [暴力解法]: 时间分析: 空间分析: ［思维问题］: ［一句话思路］: 如果为零则不相乘,优化常数的复杂度. ［输入量］:空: 正常情况:特大:特小:程序里处理到的特殊情况:异常情况(不合法不合理的输入): ［画图］: ［一刷］: 是ans[i][j] 元素变化来进行具体的加减操作,而不是无参数的ans[][] 用来声明,搞混了 ［二刷］: ［三刷］: ［四刷］: ［五刷］: [五分钟肉眼debug的…

Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7, 0, 0 ], [ 0, 0, 0 ], [ 0, 0, 1 ] ] | 1 0 0 | | 7 0 0 | | 7 0 0 | AB = | -…

Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7, 0, 0 ], [ 0, 0, 0 ], [ 0, 0, 1 ] ] | 1 0 0 | | 7 0 0 | | 7 0 0 | AB = | -…

Problem Description: Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7, 0, 0 ], [ 0, 0, 0 ], [ 0, 0, 1 ] ] | 1 0 0 | | 7 0 0…