BamUtil: validate
Status
The initial version of a SAM/BAM Validator is complete, but does not yet validate all fields or produce all desired statistics.
Download
Click the link to download the tar of the source code: bam_0.0.2.tar
This version is recommended for Unix users with access to the GNU C++ compiler.
To install the BAM Library and the BAM Validator, unpack the downloaded file (tar xvf) and type make. The BAM Validator is found in pipeline/bam and is called bam (pipeline/bam/bam).
Purpose
The BamValidator processes the specified SAM/BAM file:
- to determine if it has any syntactic or format violations.
- to generate basic statistics.
The user can then decide if they want to use the file for future processing based on whether it passed syntactic/format validation and based on the statistics that were reported.
Valid SAM/BAM File Requirements
A valid SAM/BAM file meets the validation criteria specified in SAM Validation Criteria.
Statistic Generation
The statistics only reflect alignments that were successfully read from the BAM file. Alignments that failed to parse from the file are not reflected in the statistics, but alignments that are invalid for other reasons may show up in the statistics.
The following Statistics are generated by the BAM Validator if the --disableStatistics
option is not set:
Statistic | Description |
---|---|
TotalReads | Total number of alignments that were successfully read from the file. |
MappedReads | Total number of alignments that were successfully read from the file with FLAG bit 0x004 set to 0 (not unmapped). |
PairedReads | Total number of alignments that were successfully read from the file with FLAG bit 0x001 set to 1 (paired). |
ProperPair | Total number of alignments that were successfully read from the file with FLAG bits 0x001 set to 1 (paired) AND 0x002 (proper pair). |
DuplicateReads | Total number of alignments that were successfully read from the file with FLAG bit 0x400 set to 1 (PCR or optical duplicate). |
QCFailureReads | Total number of alignments that were successfully read from the file with FLAG bit 0x200 set to 1 (failed quality checks). |
Statistic | Description |
---|---|
MappingRate(%) | 100 * MappedReads/TotalReads |
PairedReads(%) | 100 * PairedReads/TotalReads |
ProperPair(%) | 100 * ProperPair/TotalReads |
DupRate(%) | 100 * DuplicateReads/TotalReads |
QCFailRate(%) | 100 * QCFailureReads/TotalReads |
Statistic | Description |
---|---|
TotalBases | Sum of the SEQ lengths for all alignments that were successfully read from the file. |
BasesInMappedReads | Sum of the SEQ lengths for all alignments that were successfully read from the file with FLAG bit 0x004 set to 0 (not unmapped). |
NOTE: If the TotalReads is greater than 10^6, then the Read Counts and Base Counts specify the total counts divided by 10^6. This is indicated in the output with a (e6) appended to the field name.
How to Use the Bam Validator Executable
Parameters
Required Parameters: --in : the SAM/BAM file to be validated Optional Parameters: --noeof : do not expect an EOF block on a bam file. --so_flag : validate the file is sorted based on the header's @HD SO flag. --so_coord : validate the file is sorted based on the coordinate. --so_query : validate the file is sorted based on the query name. --maxErrors : Number of records with errors/invalids to allow before quiting. -1 (default) indicates to not quit until the entire file is validated. 0 indicates not to read/validate anything. --verbose : Print specific error details rather than just a summary --printableErrors : Maximum number of records with errors to print the details of before suppressing them when in verbose (defaults to 100) --disableStatistics : Turn off statistic generation
Usage
./bam validate --in <inputFile> [--noeof] [--so_flag|--so_coord|--so_query] [--maxErrors <numErrors>] [--verbose] [--printableErrors <numReportedErrors>] [--disableStatistics]
Recommended Usage
If you don't want the file statistics, use --disableStatistics.
If you want to validate that the file is sorted, use the appropriate sorting flag. If you trust the @HD SO flag, use so_flag
, otherwise if you want to check that it is sorted by coordinate, use --so_coord
.
If you want to see the error details, use --verbose, but if you want to limit the number of errors displayed, use --printableErrors.
If you just want to know if the file is validly formatted or not, use --maxErrors 1
The following will give the most information (without validating that the file is sorted):
./bam validate --in <inputFile> --verbose
Return Value
- 0: all records are successfully read, are valid, and are properly sorted.
- non-0: at least one record was not successfully read, not valid, or not properly sorted.
Example Outputs
Valid File
./bam validate --in ~/data/bamExample/37mer_alt.bwa.bam The following parameters are available. Ones with "[]" are in effect: Input Parameters --in [/home/mktrost/data/bamExample/37mer_alt.bwa.bam], --noeof, --maxErrors [-1], --verbose, --printableErrors [100], --disableStatistics SortOrder : --so_flag, --so_coord, --so_query ' Number of records read = 18900000 Number of valid records = 18900000 TotalReads(e6) 18.90 MappedReads(e6) 14.77 PairedReads(e6) 18.90 ProperPair(e6) 11.28 DuplicateReads(e6) 0.00 QCFailureReads(e6) 0.00 MappingRate(%) 78.17 PairedReads(%) 100.00 ProperPair(%) 59.68 DupRate(%) 0.00 QCFailRate(%) 0.00 TotalBases(e6) 699.30 BasesInMappedReads(e6) 546.67 Returning: 0 (SUCCESS)
Invalid File
./bam validate --in test/testFiles/testInvalid.sam The following parameters are available. Ones with "[]" are in effect: Input Parameters --in [test/testFiles/testInvalid.sam], --noeof, --maxErrors [-1], --verbose, --printableErrors [100], --disableStatistics SortOrder : --so_flag, --so_coord, --so_query Number of records read = 32 Number of valid records = 2 Error Counts: FAIL_PARSE: 17 INVALID: 1 INVALID_QNAME: 3 INVALID_RNAME: 8 INVALID_POS: 2 INVALID_CIGAR: 2 INVALID_QUAL: 2 TotalReads 14.00 MappedReads 14.00 PairedReads 6.00 ProperPair 0.00 DuplicateReads 0.00 QCFailureReads 0.00 MappingRate(%) 100.00 PairedReads(%) 42.86 ProperPair(%) 0.00 DupRate(%) 0.00 QCFailRate(%) 0.00 TotalBases 47.00 BasesInMappedReads 47.00 Returning: 7 (INVALID)
Invalid File with Verbose
Printable errors is specified to produce a smaller example that does not print all the errors since that would take up more space.
./bam validate --in test/testFiles/testInvalid.sam --verbose --printableErrors 5 The following parameters are available. Ones with "[]" are in effect: Input Parameters --in [test/testFiles/testInvalid.sam], --noeof, --maxErrors [-1], --verbose [ON], --printableErrors [5], --disableStatistics SortOrder : --so_flag, --so_coord, --so_query Record 1 INVALID_QNAME (ERROR) : Invalid Query Name - the string length (256) does not match the specified query name length (0). INVALID_QNAME (WARNING) : Invalid Query Name (QNAME) length: 256. Length with the terminating null must be between 2 & 255. Record 2 INVALID: 0 length Query Name. Record 3 INVALID_QNAME (WARNING) : Invalid character in the Query Name (QNAME): ' ' at position 2. Record 4 FAIL_PARSE: flag, 29M5I3M:F:295, is not an integer. FAIL_PARSE: Invalid Tag Format: *, should be cc:c:x*. Record 5 FAIL_PARSE: Too few columns (1) in the Record, expected at least 11. Number of records read = 32 Number of valid records = 2 Error Counts: FAIL_PARSE: 17 INVALID: 1 INVALID_QNAME: 3 INVALID_RNAME: 8 INVALID_POS: 2 INVALID_CIGAR: 2 INVALID_QUAL: 2 TotalReads 14.00 MappedReads 14.00 PairedReads 6.00 ProperPair 0.00 DuplicateReads 0.00 QCFailureReads 0.00 MappingRate(%) 100.00 PairedReads(%) 42.86 ProperPair(%) 0.00 DupRate(%) 0.00 QCFailRate(%) 0.00 TotalBases 47.00 BasesInMappedReads 47.00 Returning: 7 (INVALID)