LibStatGen: FASTQ

Validation Criteria

Sequence Identifier Line

Validation Criteria	Error Message
Every entry in the file should have a unique identifier.	ERROR on Line <current line #>: Repeated Sequence Identifier: <identifier> at Lines <previous line #> <current line #>

Raw Sequence Line

• A base sequence should have non-zero length.
• Validates the base sequences against the characters allowed via configuration.
  • Base Only: A C T G N a c t g n
  • Color Space Only: 0 1 2 3 .(period)
  • Base or Color Space: A C T G N a c t g n 0 1 2 3 .(period)
• Reads should be of a minimum length; many mappers will get into trouble with very short reads.

Quality String Line

• A quality string should be present for every base sequence.
• Paired quality and base sequences should be of the same length.
• Valid quality values should all have ASCII codes > 32.

Additional Features

• Base composition are reported and tracked by position.
• Consumes gzipped and uncompressed text files transparently (see libcsg/InputFile.h).

Additional Wishlist - Not Implemented

• To reduce memory usage, implement a two-pass algorithm that stores only a key for each sequence name (rather than complete sequence names) in memory (suggest a pair of options -1 -> one pass, high memory use, -2 -> two pass lower memory use, default is -1).

How to Use the fastQValidator Executable

Required Parameters:

       -f  :  FastQ filename with path to be prorcessed.

Optional Parameters:

       -l  :  Minimum allowed read length (Defaults to 10).
       -e  :  Maximum number of errors to display before suppressing them(Defaults to 20).
       -b  :  Raw sequence type:  B - ACTGN only (Default)
                                  C - 0123. only
                                 BC - ACTGN or 0123.

Testing only Parameters:

       -t  :  If "ReadOnly" is specified, the fastq will be read but not processed.  This may be used for determining read time.

Usage:

       ./fastQValidator -f <fileName> -l <minReadLen> -e <maxReprotedErrors> -b <rawSeqType>

Examples:

       ../fastQValidator -f testFile.txt
       ../fastQValidator -f testFile.txt -l 10 -b BC -e 100
       ./fastQValidator -f test/testFile.txt -l 10 -b BC -e 100
       time ./fastQValidator -f test/testFile.txt -t ReadOnly

FastQ Validator Output

Coming Soon