ChIP-seq Peak caller MACS index out of range问题解决

使用MACS1.4 进行peak calling的时候发现一个比较奇怪的问题：

我的某些文件无法被MACS1.4 进行peak calling，出现如下的信息：

Traceback (most recent call last):
  File "/usr/local/bin/macs14", line 5, in <module>
    pkg_resources.run_script('MACS==1.4.2', 'macs14')
  File "/Library/Python/2.7/site-packages/distribute-0.6.34-py2.7.egg/pkg_resources.py", line 505, in run_script
    self.require(requires)[0].run_script(script_name, ns)
  File "/Library/Python/2.7/site-packages/distribute-0.6.34-py2.7.egg/pkg_resources.py", line 1252, in run_script
    exec script_code in namespace, namespace
  File "/Library/Python/2.7/site-packages/MACS-1.4.2-py2.7.egg/EGG-INFO/scripts/macs14", line 366, in <module>

  File "/Library/Python/2.7/site-packages/MACS-1.4.2-py2.7.egg/EGG-INFO/scripts/macs14", line 124, in main

  File "build/bdist.macosx-10.7-intel/egg/MACS14/PeakModel.py", line 76, in __init__
  File "build/bdist.macosx-10.7-intel/egg/MACS14/PeakModel.py", line 112, in build
  File "build/bdist.macosx-10.7-intel/egg/MACS14/PeakModel.py", line 172, in __paired_peak_model
IndexError: list index out of range

网上并没有很好的解决办法。最终自己尝试后，发现这可能是程序building model时出错。可以将MACS的peak calling模式改为“--nomodel”，即可得到peak，效果并不差。

macs14 -t chip-seq_experiment -c chip-seq_input --nomodel ...