How do you convert SAM to BAM?
To convert SAM to BAM, we use the samtools view command. We must specify that our input is in SAM format (by default it expects BAM) using the -S option. We must also say that we want the output to be BAM (by default it produces BAM) with the -b option.
How is BAM file coverage calculated?
If you want to get the average coverage: add up the product of bases per coverage [2* 4+3* 28+4* 10+…] and divide by the total number of bases [137928].
What is SAMtools index?
DESCRIPTION. Samtools is a set of utilities that manipulate alignments in the SAM (Sequence Alignment/Map), BAM, and CRAM formats. It converts between the formats, does sorting, merging and indexing, and can retrieve reads in any regions swiftly. Samtools is designed to work on a stream.
What does SAMtools collate do?
A faster alternative to a full query name sort, collate ensures that reads of the same name are grouped together in contiguous groups, but doesn’t make any guarantees about the order of read names between groups.
Are BAM files smaller than SAM?
For almost any application that requires SAM input, this can be created on the fly from a BAM file (using ‘samtools view reads. bam |’). BAM files take up much less space than SAM files. For archiving purposes, keep only the BAM file.
What is BAM coverage?
This tool takes an alignment of reads or fragments as input (BAM file) and generates a coverage track (bigWig or bedGraph) as output. The coverage is calculated as the number of reads per bin, where bins are short consecutive counting windows of a defined size.
How long does SAMtools sort take?
We compared the sorting speed of a 25Gb unsorted BAM file with SAMtools and sambamba. Our results show that sambamba was 2x faster than SAMtools. The following violin plot shows that SAMtools took 20 minutes while sambamba could sort the same file in 10 minutes.
What is the difference between SAM BAM and CRAM?
SAM files are human-readable text files, and BAM files are simply their binary equivalent, whilst CRAM files are a restructured column-oriented binary container format. BAM files are typically compressed and more efficient for software to work with than SAM.
What is the difference between a SAM and BAM file?
BAM files contain the same information as SAM files, except they are in binary file format which is not readable by humans. On the other hand, BAM files are smaller and more efficient for software to work with than SAM files, saving time and reducing costs of computation and storage.
How do I check my BAM index?
For viewing BAM files, an index file must be found in the same directory as the BAM file. The index should be named by appending “. bai” to the BAM file name. If there is no index file, you can use SAMTools to create one (please download SAMTools from http://samtools.sourceforge.net and install locally).
How long does samtools view take?
For instance, samtools view on a 40GB bam file and ~5000 regions from various contigs takes 12 min to run, while the equivalent command launched from Rsamtools (which uses the bam index) takes 13 s.
Are BAM files smaller than SAM files?
BAM files take up much less space than SAM files.
How do I convert Sam to BAM in SAMtools?
More on that later. To convert SAM to BAM, we use the samtools view command. We must specify that our input is in SAM format (by default it expects BAM) using the -S option. We must also say that we want the output to be BAM (by default it produces BAM) with the -b option.
What is the goal of the SAMtools project?
Our goal is to work through examples that demonstrate how to explore, process and manipulate SAM and BAM files with the samtools software package. For future reference, use the samtools documentation.
What is the difference between SAMtools and BedTools?
SAMtools discards unmapped reads, secondary alignments and duplicates. To consider also secondary alignments, BEDtools could be an alternative.