这就是我的数据在文件中的排列方式
c65194_g1_i1 -21.9509530657044 13.2266114245427 1.26719984587427e-44 1.73042474953361e-39
c29053_g1_i1 -21.7830220218917 13.0586642598416 4.05844989803944e-44 2.77100812913388e-39
c63097_g1_i1 -21.4616315169133 12.7372371455793 3.76550367403328e-43 1.71399451402538e-38
c15833_g1_i1 -21.3337075582514 12.6092961895881 9.1390133914486e-43 3.11994493417316e-38
c54104_g1_i1 -20.9476922994263 12.2232194785508 1.32699572263938e-41 3.62415801810041e-37
c72466_g1_i1 -20.7117075903545 11.9871882514396 6.8114568592363e-41 1.55023081902169e-36
c54551_g1_i1 -20.6402597636308 11.9157247731746 1.11763325249107e-40 2.18026298277025e-36
c16812_g1_i1 -19.9803901665057 11.2556673199183 1.0829030885624e-38 1.84844789073297e-34
c52174_g1_i1 -17.3946586876797 11.1994819594618 1.59840414284341e-38 2.42522308584424e-34
c61394_g3_i1 -19.7919324674417 11.0671382066934 3.99837801243703e-38 5.45998509488338e-34
c63720_g1_i1 -19.7442542319924 11.0194403765143 5.56416938462837e-38 6.9074104574357e-34
c52697_g1_i3 -19.7121643690573 10.9873369560405 6.95007628588691e-38 7.42715989045943e-34
c54027_g2_i2 -19.7096756788425 10.9848472017346 7.07063663549284e-38 7.42715989045943e-34
c55424_g1_i2 -14.9238636253627 10.5276723871648 1.67866916859075e-36 1.63736191654935e-32
c53640_g1_i1 -18.9525614294271 10.2273069100634 1.34402113000358e-35 1.22355203605092e-31
c49936_g1_i1 -18.9066537149149 10.1813654615637 1.84747309451501e-35 1.57676055263436e-31
c61346_g1_i2 -14.4532346909692 10.0567336871647 4.37960869176717e-35 3.51798508767215e-31
c52697_g1_i4 -18.637842793771 9.91233394513217 1.19009210093315e-34 9.02850149127368e-31
c53336_g2_i1 -18.5076080431514 9.78197660837233 2.93451761200646e-34 2.10906869740812e-30
c13587_g1_i1 -18.4719269225614 9.74625992614394 3.75786641185474e-34 2.56577723935412e-30
c48254_g1_i1 -18.4479382811535 9.72224687735655 4.43827627976478e-34 2.88604198753943e-30
c53513_g1_i1 -18.3774595626302 9.65169405756151 7.23348927630069e-34 4.48985967329655e-30
c52353_g2_i1 -18.3691781540535 9.64340370193521 7.6593042463829e-34 4.54746213636877e-30
c56356_g1_i3 -18.2534296819214 9.5275246522986 1.70868862762047e-33 9.72208231436306e-30
c41529_g2_i1 -18.1994639286288 9.47349434618108 2.48348881197431e-33 1.35653125887661e-29
是否可以使用Perl将这些数字提取到.001以下？所有以e - （随机值）结尾的否定和数字都在.001之下。我还没有找到解决问题的解决方案。请指教。
答案 0 :(得分：5)
不需要正则表达式：
use Modern::Perl;
while(<DATA>) {
chomp;
my @nums = split;
shift @nums;
for (@nums) {
say $_ if $_ < 0.001;
}
}
__DATA__
c65194_g1_i1 -21.9509530657044 13.2266114245427 1.26719984587427e-44 1.73042474953361e-39
c29053_g1_i1 -21.7830220218917 13.0586642598416 4.05844989803944e-44 2.77100812913388e-39
c63097_g1_i1 -21.4616315169133 12.7372371455793 3.76550367403328e-43 1.71399451402538e-38
<强>输出：
-21.9509530657044
1.26719984587427e-44
1.73042474953361e-39
-21.7830220218917
4.05844989803944e-44
2.77100812913388e-39
-21.4616315169133
3.76550367403328e-43
1.71399451402538e-38
答案 1 :(得分：1)
-\d+(?:\.\d+)?\b|\b\d+\.\d*e-\d+\b|\b\.000\d+\b
你可以试试这样的东西，虽然通过数学比较应该很容易。参见演示。
答案 2 :(得分：1)
这实际上会告诉您出现这些值的行和列：
#!/usr/bin/env perl
use strict;
use warnings;
while (my $obs = <DATA>) {
next unless $obs =~ /\S/;
my ($id, @vals) = split ' ', $obs;
my @small = grep $vals[$_] < 0.001, 0 .. $#vals;
for my $i (@small) {
print "${id}[$i]: $vals[$i]\n";
}
}
__DATA__
c65194_g1_i1 -21.9509530657044 13.2266114245427 1.26719984587427e-44 1.73042474953361e-39
c29053_g1_i1 -21.7830220218917 13.0586642598416 4.05844989803944e-44 2.77100812913388e-39
c63097_g1_i1 -21.4616315169133 12.7372371455793 3.76550367403328e-43 1.71399451402538e-38
c15833_g1_i1 -21.3337075582514 12.6092961895881 9.1390133914486e-43 3.11994493417316e-38
c54104_g1_i1 -20.9476922994263 12.2232194785508 1.32699572263938e-41 3.62415801810041e-37
c72466_g1_i1 -20.7117075903545 11.9871882514396 6.8114568592363e-41 1.55023081902169e-36
c54551_g1_i1 -20.6402597636308 11.9157247731746 1.11763325249107e-40 2.18026298277025e-36
c16812_g1_i1 -19.9803901665057 11.2556673199183 1.0829030885624e-38 1.84844789073297e-34
c52174_g1_i1 -17.3946586876797 11.1994819594618 1.59840414284341e-38 2.42522308584424e-34
c61394_g3_i1 -19.7919324674417 11.0671382066934 3.99837801243703e-38 5.45998509488338e-34
c63720_g1_i1 -19.7442542319924 11.0194403765143 5.56416938462837e-38 6.9074104574357e-34
c52697_g1_i3 -19.7121643690573 10.9873369560405 6.95007628588691e-38 7.42715989045943e-34
c54027_g2_i2 -19.7096756788425 10.9848472017346 7.07063663549284e-38 7.42715989045943e-34
c55424_g1_i2 -14.9238636253627 10.5276723871648 1.67866916859075e-36 1.63736191654935e-32
c53640_g1_i1 -18.9525614294271 10.2273069100634 1.34402113000358e-35 1.22355203605092e-31
c49936_g1_i1 -18.9066537149149 10.1813654615637 1.84747309451501e-35 1.57676055263436e-31
c61346_g1_i2 -14.4532346909692 10.0567336871647 4.37960869176717e-35 3.51798508767215e-31
c52697_g1_i4 -18.637842793771 9.91233394513217 1.19009210093315e-34 9.02850149127368e-31
c53336_g2_i1 -18.5076080431514 9.78197660837233 2.93451761200646e-34 2.10906869740812e-30
c13587_g1_i1 -18.4719269225614 9.74625992614394 3.75786641185474e-34 2.56577723935412e-30
c48254_g1_i1 -18.4479382811535 9.72224687735655 4.43827627976478e-34 2.88604198753943e-30
c53513_g1_i1 -18.3774595626302 9.65169405756151 7.23348927630069e-34 4.48985967329655e-30
c52353_g2_i1 -18.3691781540535 9.64340370193521 7.6593042463829e-34 4.54746213636877e-30
c56356_g1_i3 -18.2534296819214 9.5275246522986 1.70868862762047e-33 9.72208231436306e-30
c41529_g2_i1 -18.1994639286288 9.47349434618108 2.48348881197431e-33 1.35653125887661e-29
输出：
c65194_g1_i1[0]: -21.9509530657044 c65194_g1_i1[2]: 1.26719984587427e-44 c65194_g1_i1[3]: 1.73042474953361e-39 c29053_g1_i1[0]: -21.7830220218917 c29053_g1_i1[2]: 4.05844989803944e-44 c29053_g1_i1[3]: 2.77100812913388e-39 c63097_g1_i1[0]: -21.4616315169133 c63097_g1_i1[2]: 3.76550367403328e-43 c63097_g1_i1[3]: 1.71399451402538e-38 c15833_g1_i1[0]: -21.3337075582514 c15833_g1_i1[2]: 9.1390133914486e-43 c15833_g1_i1[3]: 3.11994493417316e-38 c54104_g1_i1[0]: -20.9476922994263 c54104_g1_i1[2]: 1.32699572263938e-41 c54104_g1_i1[3]: 3.62415801810041e-37 c72466_g1_i1[0]: -20.7117075903545 c72466_g1_i1[2]: 6.8114568592363e-41 c72466_g1_i1[3]: 1.55023081902169e-36 c54551_g1_i1[0]: -20.6402597636308 c54551_g1_i1[2]: 1.11763325249107e-40 c54551_g1_i1[3]: 2.18026298277025e-36 c16812_g1_i1[0]: -19.9803901665057 c16812_g1_i1[2]: 1.0829030885624e-38 c16812_g1_i1[3]: 1.84844789073297e-34 c52174_g1_i1[0]: -17.3946586876797 c52174_g1_i1[2]: 1.59840414284341e-38 c52174_g1_i1[3]: 2.42522308584424e-34 c61394_g3_i1[0]: -19.7919324674417 c61394_g3_i1[2]: 3.99837801243703e-38 c61394_g3_i1[3]: 5.45998509488338e-34 c63720_g1_i1[0]: -19.7442542319924 c63720_g1_i1[2]: 5.56416938462837e-38 c63720_g1_i1[3]: 6.9074104574357e-34 c52697_g1_i3[0]: -19.7121643690573 c52697_g1_i3[2]: 6.95007628588691e-38 c52697_g1_i3[3]: 7.42715989045943e-34 c54027_g2_i2[0]: -19.7096756788425 c54027_g2_i2[2]: 7.07063663549284e-38 c54027_g2_i2[3]: 7.42715989045943e-34 c55424_g1_i2[0]: -14.9238636253627 c55424_g1_i2[2]: 1.67866916859075e-36 c55424_g1_i2[3]: 1.63736191654935e-32 c53640_g1_i1[0]: -18.9525614294271 c53640_g1_i1[2]: 1.34402113000358e-35 c53640_g1_i1[3]: 1.22355203605092e-31 c49936_g1_i1[0]: -18.9066537149149 c49936_g1_i1[2]: 1.84747309451501e-35 c49936_g1_i1[3]: 1.57676055263436e-31 c61346_g1_i2[0]: -14.4532346909692 c61346_g1_i2[2]: 4.37960869176717e-35 c61346_g1_i2[3]: 3.51798508767215e-31 c52697_g1_i4[0]: -18.637842793771 c52697_g1_i4[2]: 1.19009210093315e-34 c52697_g1_i4[3]: 9.02850149127368e-31 c53336_g2_i1[0]: -18.5076080431514 c53336_g2_i1[2]: 2.93451761200646e-34 c53336_g2_i1[3]: 2.10906869740812e-30 c13587_g1_i1[0]: -18.4719269225614 c13587_g1_i1[2]: 3.75786641185474e-34 c13587_g1_i1[3]: 2.56577723935412e-30 c48254_g1_i1[0]: -18.4479382811535 c48254_g1_i1[2]: 4.43827627976478e-34 c48254_g1_i1[3]: 2.88604198753943e-30 c53513_g1_i1[0]: -18.3774595626302 c53513_g1_i1[2]: 7.23348927630069e-34 c53513_g1_i1[3]: 4.48985967329655e-30 c52353_g2_i1[0]: -18.3691781540535 c52353_g2_i1[2]: 7.6593042463829e-34 c52353_g2_i1[3]: 4.54746213636877e-30 c56356_g1_i3[0]: -18.2534296819214 c56356_g1_i3[2]: 1.70868862762047e-33 c56356_g1_i3[3]: 9.72208231436306e-30 c41529_g2_i1[0]: -18.1994639286288 c41529_g2_i1[2]: 2.48348881197431e-33 c41529_g2_i1[3]: 1.35653125887661e-29