根据共同的 2 列正确连接两个文件 [英] properly join two files based on 2 columns in common
问题描述
我有两个文件我正在尝试基于 1 和 2 列加入/合并.它们看起来像这样，file1(58210 行)比 file2(815530 行)短得多，并且我想根据字段 1 和 2 作为索引找到这两个文件的交集:
I have two files I'm trying to join/merge based on columns 1 and 2. They look something like this, with file1 (58210 lines) being much shorter than file2 (815530 lines) and I'd like to find the intersection of these two files based on fields 1 and 2 as an index:
file1:
2L 25753 33158
2L 28813 33158
2L 31003 33158
2L 31077 33161
2L 31279 33161
3L 32124 45339
3L 33256 45339
...
file2:
2L 20242 0.5 0.307692307692308
2L 22141 0.32258064516129 0.692307692307692
2L 24439 0.413793103448276 0.625
2L 24710 0.371428571428571 0.631578947368421
2L 25753 0.967741935483871 0.869565217391304
2L 28813 0.181818181818182 0.692307692307692
2L 31003 0.36 0.666666666666667
2L 31077 0.611111111111111 0.931034482758621
2L 31279 0.75 1
3L 32124 0.558823529411765 0.857142857142857
3L 33256 0.769230769230769 0.90625
...
我一直在使用以下几个命令，但最终得到的行数不同:
I've been using the following couple of commands but end up with different numbers of lines:
awk 'FNR==NR{a[$1$2]=$3;next} {if($1$2 in a) print}' file1 file2 | wc -l
awk 'FNR==NR{a[$1$2]=$3;next} {if($1$2 in a) print}' file2 file1 | wc -l
我不确定为什么会发生这种情况，我已经尝试在比较之前进行排序，以防万一我有重复的行(基于列 1 和 2) 在任何一个文件中，但它似乎没有帮助.(任何有关为什么会这样的见解也值得赞赏)
I'm not sure why this happens, and I've tried sorting prior to comparison, just in case I have duplicate lines (based on columns 1 and 2) in either of the files, but it doesn't seem to help. (Any insights on why this is so are also appreciated)
我怎样才能合并文件，以便只有 file2 的行在 中具有相应的列 被打印出来，加上 1 和 2file1file1 的 3 列，看起来像这样:
How can I just merge the files so that just the lines of file2 that have the corresponding columns 1 and 2 in file1 get printed, with column 3 of file1 added on, to look something like this:
2L 25753 0.967741935483871 0.869565217391304 33158
2L 28813 0.181818181818182 0.692307692307692 33158
2L 31003 0.36 0.666666666666667 33158
2L 31077 0.611111111111111 0.931034482758621 33161
2L 31279 0.75 1 33161
3L 32124 0.558823529411765 0.857142857142857 45339
3L 33256 0.769230769230769 0.90625 45339
推荐答案
awk 'NR==FNR{a[$1,$2]=$3;next} ($1,$2) in a{print $0, a[$1,$2]}' file1 file2
看:
$ cat file1
2L 5753 33158
2L 8813 33158
2L 7885 33159
2L 1279 33159
2L 5095 33158
$
$ cat file2
2L 8813 0.6 1.2
2L 5762 0.4 0.5
2L 1279 0.5 0.9
$
$ awk 'NR==FNR{a[$1,$2]=$3;next} ($1,$2) in a{print $0, a[$1,$2]}' file1 file2
2L 8813 0.6 1.2 33158
2L 1279 0.5 0.9 33159
$
如果这不是您想要的，请澄清并发布一些更具代表性的示例输入/输出.
If that's not what you want, please clarify and perhaps post some more representative sample input/output.
上述代码的注释版本以提供所需的解释:
Commented version of the above code to provide requested explanation:
awk ' # START SCRIPT
# IF the number of records read so far across all files is equal
# to the number of records read so far in the current file, a
# condition which can only be true for the first file read, THEN
NR==FNR {
# populate array "a" such that the value indexed by the first
# 2 fields from this record in file1 is the value of the third
# field from the first file.
a[$1,$2]=$3
# Move on to the next record so we don't do any processing intended
# for records from the second file. This is like an "else" for the
# NR==FNR condition.
next
} # END THEN
# We only reach this part of the code if the above condition is false,
# i.e. if the current record is from file2, not from file1.
# IF the array index constructed from the first 2 fields of the current
# record exist in array a, as would occur if these same values existed
# in file1, THEN
($1,$2) in a {
# print the current record from file2 followed by the value from file1
# that occurred at field 3 of the record that had the same values for
# field 1 and field 2 in file1 as the current record from file2.
print $0, a[$1,$2]
} # END THEN
' file1 file2 # END SCRIPT
希望有所帮助.
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