hamstring 1.1

[](https://travis-ci.org/mdshw5/hamstring)
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This python module generates, checks, and corrects quaternary Hamming barcodes. The theory for generating quaternary (DNA) Hamming barcodes comes from the publication [Bystrykh, L. V. (2012). Generalized DNA Barcode Design Based on Hamming Codes. PLoS ONE](http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036852). Currently, the `hamstring` module only works with Hamming7,4 encoding, but may be generalized to other sizes of data and parity bits.

[](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0036852#pone-0036852-g001)

## Usage

**Generate Hamming DNA barcodes**

generateBarcodes.py [-h] out

arguments:
out output barcode file name
-h, --help show this help message and exit
-p PARITY, --parity PARITY
length of the parity bit e.g. 4 for Hamming8,4.
default=3

example output:

index base4 nucleotide gc
0 0000000 AAAAAAA 0.0
1 3303001 TTATAAC 0.14
2 2202002 GGAGAAG 0.57
3 1101003 CCACAAT 0.43
4 0303010 ATATACA 0.14

**Checksum a list of Hamming DNA barcodes**

checkBarcodes.py [-h] list

arguments:
list list of barcodes to check, one per line
-h, --help show this help message and exit
-p PARITY, --parity PARITY
length of the parity bit e.g. 4 for Hamming8,4.
default=3

example output:

in fixed checksum
CATAACT CAAAACT A > T at pos 3
AGAGAGA AGAGAGA ok
TCACAGC TCACAGC ok
GAACAGG GAAAAGG A > C at pos 4
CTATAGT CTATAGT ok
TTTAAAN NNNNNNN bad
NNNNNNN NNNNNNN bad

**Tag fastq reads with a barcode (for generating a simulated dataset)**

tagReads.py [-h] -e nb fastq out

arguments:
nb number of barcodes to generate
fastq fastq file to process
out name for new fastq file
-e, --erate error rate for single barcode base errors. default=0.05
-p PARITY, --parity PARITY
length of the parity bit e.g. 4 for Hamming8,4.
default=3
-h, --help show this help message and exit

example input:

@HWI-EAS179_0001:5:1:7:119#0/1
CAGGGCGCGAATGNTTTGAGAGGGANATTGGAAANNNNNGATAGANNGGNCTATNNTGNNNNNNNNNNNNNNNNNN
+
HIHHHGHHHFDHH#EHHH?HHHDH>#DGGG@7@?##########################################

example output:

@HWI-EAS179_0001:5:1:7:119#0/1
CCATGGCCAGGGCGCGAATGNTTTGAGAGGGANATTGGAAANNNNNGATAGANNGGNCTATNNTGNNNNNNNNNNNNNNNNNN
+
HHHHHHHHIHHHGHHHFDHH#EHHH?HHHDH>#DGGG@7@?##########################################

**Check and fix barcodes in fastq file**

fixFastq.py [-h] [-s] list fastq out

arguments:
list list of barcodes used in experiment, one per line
fastq fastq file to process
out name for new fastq file
-s, --strict change all barcodes not in list to 'N'
-h, --help show this help message and exit

example input:

@HWI-EAS179_0001:5:1:7:119#0/1
GCATGGCCAGGGCGCGAATGNTTTGAGAGGGANATTGGAAANNNNNGATAGANNGGNCTATNNTGNNNNNNNNNNNNNNNNNN
+
HHHHHHHHIHHHGHHHFDHH#EHHH?HHHDH>#DGGG@7@?##########################################

example output:

@HWI-EAS179_0001:5:1:7:119#0/1
CCATGGCCAGGGCGCGAATGNTTTGAGAGGGANATTGGAAANNNNNGATAGANNGGNCTATNNTGNNNNNNNNNNNNNNNNNN
+
HHHHHHHHIHHHGHHHFDHH#EHHH?HHHDH>#DGGG@7@?##########################################

## Requirements

- Python 2.7 or Python 3.2+

## Hamstring Module

The core hamstring module has no external module dependencies and should run under any OS.

`base4Encode(n,d)` is used to convert decimal notation *n* to quaternary notation with *d* leading digits. *example*:

hamstring.base4Encode(22, 4)
[0, 1, 1, 2]

`generateHamming(data,parity)` is used to generate DNA quaternary Hamming codes from list of quaternary digits *data* with *parity* number of parity bits.
*example*:

```python
>>> generateHamming([0,1,1,2], 3)
Barcode(base4='1100112', nucleotide='CCAACCG', gc=0.71)

>>> generateHamming([0,1,1,2], 4)
Barcode(base4='11001122', nucleotide='CCAACCGG', gc=0.75)
```

`decodeHamming(barcode,parity)` is used to decode *barcode* nucleotide Hamming string with *parity* number of parity bits, and perform error correction if needed.
*example*:

```python
>>> decodeHamming('CCAACCG', 3)
CheckedBarcode(nucleotide='CCAACCG', chksum='ok')

>>> decodeHamming('CCAACCGG', 4)
CheckedBarcode(nucleotide='CCAACCGG', chksum='ok')

>>> decodeHamming('CCATCCG', 3)
CheckedBarcode(nucleotide='CCAACCG', chksum='A > T at pos 4')

>>> decodeHamming('CCATCCGG', 4)
CheckedBarcode(nucleotide='CCAACCGG', chksum='A > T at pos 4')

>>> decodeHamming('TCATCCGG', 4)
CheckedBarcode(nucleotide='NNNNNNNN', chksum='bad')
```

## Author

Matt Shirley - mdshw5'at'gmail'.'com - [http://mattshirley.com](http://mattshirley.com)