小编use*_*112的帖子

我有一个像1,1,2,1,...的列,我想得到1和2的频率,我做了

SELECT count(column)
FROM table
WHERE column = 1;

SELECT count(column)
FROM table
WHERE column = 2;

但是,我能以更直接的方式采用频率吗？

我有一个按制表符分隔的数据集,所以我想将以下数据集转换为矩阵

CATGGGGAAAACTGA
CCTCTCGATCACCGA
CCTATAGATCACCGA
CCGATTGATCACCGA
CCTTGTGCAGACCGA

我以前用过

rbind(strsplit("CATGGGGAAAACTGA","")[[1]],
        strsplit("CCTCTCGATCACCGA","")[[1]],
        strsplit("CCTCTCGATCACCGA","")[[1]],
        strsplit("CCTATAGATCACCGA","")[[1]],
        strsplit("CCGATTGATCACCGA","")[[1]],
        strsplit("CCTTGTGCAGACCGA","")[[1]])

这会产生:

[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14] [,15]
[1,] "C"  "A"  "T"  "G"  "G"  "G"  "G"  "A"  "A"  "A"   "A"   "C"   "T"   "G"   "A"  
[2,] "C"  "C"  "T"  "C"  "T"  "C"  "G"  "A"  "T"  "C"   "A"   "C"   "C"   "G"   "A"  
[3,] "C"  "C"  "T"  "C"  "T"  "C"  "G"  "A"  "T"  "C"   "A"   "C"   "C"   "G"   "A"  
[4,] "C"  "C" …