A highly parallelized utility for analyzing metrics at a per-base level.
If a metric is missing, or performance is lacking. Please file a bug/feature ticket in issues.
Why perbase when so many other tools are out there? perbase leverages Rust's concurrency system to automagically parallelize over your input regions. This leads to orders of magnitude faster runtimes that scale with the compute resources that you have available. Additionally, perbase aims to be more accurate than other tools. E.g.: perbase counts DELs toward depth, bam-readcount does not, perbase does not count REF_SKIPs toward depth, sambamba does.
conda install -c bioconda perbase
# or via the rust toolchain
cargo install perbase* Check version, conda lags behind what you will find in the release page
You can also download a binary from the releases page.
The base-depth tool walks over every position in the BAM/CRAM file and calculates the depth, as well as the number of each nucleotide at the given position. Additionally, it counts the numbers of Ins/Dels at each position.
The output columns are as follows:
| Column | Description |
|---|---|
| REF | The reference sequence name |
| POS | The position on the reference sequence |
| REF_BASE | The reference base at the position, column excluded if no reference was supplied |
| DEPTH | The total depth at the position SUM(A, C, T, G, DEL) |
| A | Total A nucleotides seen at this position |
| C | Total C nucleotides seen at this position |
| G | Total G nucleotides seen at this position |
| T | Total T nucleotides seen at this position |
| N | Total N nucleotides seen at this position |
| INS | Total insertions that start at the base to the right of this position |
| DEL | Total deletions covering this position |
| REF_SKIP | Total reference skip operations covering this position |
| FAIL | Total reads failing filters that covered this position (their bases were not counted toward depth) |
| NEAR_MAX_DEPTH | Flag to indicate if this position came within 1% of the max depth specified |
perbase base-depth ./test/test.bamExample output
REF POS REF_BASE DEPTH A C G T N INS DEL REF_SKIP FAIL NEAR_MAX_DEPTH
chr1 709636 T 16 0 0 0 16 0 0 0 0 0 false
chr1 709637 T 16 0 4 0 12 0 0 0 0 0 false
chr1 709638 A 16 16 0 0 0 0 0 0 0 0 false
chr1 709639 G 16 0 0 16 0 0 0 0 0 0 false
chr1 709640 A 16 16 0 0 0 0 0 0 0 0 false
chr1 709641 A 16 16 0 0 0 0 0 0 0 0 false
chr1 709642 G 16 0 0 16 0 0 0 0 0 0 false
chr1 709643 G 16 0 0 16 0 0 0 0 0 0 false
chr1 709644 T 16 0 0 0 16 0 0 0 0 0 false
chr1 709645 G 16 0 0 16 0 0 0 0 0 0 false
If the --mate-fix flag is passed, each position will first check if there are any mate overlaps and choose the mate with the hightest MAPQ, breaking ties by choosing the first mate that passes filters. Mates that are discarded are not counted toward FAIL or DEPTH.
If the --reference-fasta is supplied, the REF_BASE field will be filled in. The reference must be indexed an match the BAM/CRAM header of the input.
The output can be compressed and indexed as follows:
perbase base-depth ./test/test.bam | bgzip > output.tsv.gz
tabix -S 1 -s 1 -b 2 -e 2 ./output.tsv.gz
# Query all positions overlapping region
tabix output.tsv.gz chr1:5-10Usage:
Calculate the depth at each base, per-nucleotide
USAGE:
perbase base-depth [FLAGS] [OPTIONS] <reads>
FLAGS:
-h, --help Prints help information
-m, --mate-fix Fix overlapping mates counts, see docs for full details
-V, --version Prints version information
-z, --zero-base Output positions as 0-based instead of 1-based
OPTIONS:
-B, --bcf-file <bcf-file> A BCF/VCF file containing positions of interest. If specified, only bases
from the given positions will be reported on
-b, --bed-file <bed-file> A BED file containing regions of interest. If specified, only bases from
the given regions will be reported on
-c, --chunksize <chunksize> The ideal number of basepairs each worker receives. Total bp in memory at
one time is (threads - 2) * chunksize
-F, --exclude-flags <exclude-flags> SAM flags to exclude, recommended 3848 [default: 0]
-f, --include-flags <include-flags> SAM flags to include [default: 0]
-D, --max-depth <max-depth> Set the max depth for a pileup. If a positions depth is within 1% of max-
depth the `NEAR_MAX_DEPTH` output field will be set to true and that
position should be viewed as suspect [default: 100000]
-q, --min-mapq <min-mapq> Minimum MAPQ for a read to count toward depth [default: 0]
-o, --output <output> Output path, defaults to stdout
--ref-cache-size <ref-cache-size> Number of Reference Sequences to hold in memory at one time. Smaller will
decrease mem usage [default: 10]
-r, --ref-fasta <ref-fasta> Indexed reference fasta, set if using CRAM
-t, --threads <threads> The number of threads to use [default: 16]
ARGS:
<reads> Input indexed BAM/CRAM to analyze
The only-depth tool walks over the input BAM/CRAM file and calculates the depth over all positions specified by either a BED file or in the BAM/CRAM header. Adjacent positions that have the same depth will be merged together to form a non-inclusive range (see example output).
There are two distinct modes that only-depth can run in, gated by the --fast-mode flag. When running in fast-mode, only depth over the area a read covers is only determined by the reads start and end postions, and no cigar related info is taken into account. --mate-fix may still be used in this mode, and areas where mates overlap will not be counted twice.
Without the --fast-mode flag, the depth at each position is determined in a manner similar to base-depth where DEL will count toward depth, but REF_SKIP will not. Additionally, any reads that fail the --exclude-flags will not be counted toward depth. Lastly, --mate-fix can be applied to avoid counting regions twice where mates may overlap.
Regarding mate fixes, perbase will make "fixes" based only on the counted regions in a read. For example, if you have a read that goes from "chr1:0-1000" with a CIGAR of "25M974N1M", and the mate aligns nicely at "chr1:45-70" with CIGAR "25M", the mate will count toward the depth over "chr1:45-74". This is in contrast to other tools that will reject the mate even though it overlaps a region of R1 that is not counted toward depth.
For the fastest possible output, use only-depth --fast-mode.
Note that it is possible that two adjacent positions may not merge if they fall at a --chunksize boundary. If this is an issue you can set the --chunksize to the size of the largest contig in question. At a future date this may be fixed or a post processing tool may be provided to fix it. For most use cases this should not be a problem. Additionally, you can pipe into merge-adjcent which will fix it as well. EX: perbase only-depth -m file.bam | perbase merge-adjacent > out.tsv.
Example output of perbase only-depth --mate-fix --zero-base ./test/test.bam:
REF POS END DEPTH
chr2 0 4 1
chr2 4 9 2
chr2 9 12 3
chr2 12 14 2
chr2 14 17 3
chr2 17 19 4
chr2 19 23 5
chr2 23 34 4
chr2 34 39 3
chr2 39 49 1
chr2 49 54 2
chr2 54 64 3
chr2 64 74 4
chr2 74 79 3
chr2 79 84 2
chr2 84 89 1
Usage:
Calculate the only the depth at each base
USAGE:
perbase only-depth [FLAGS] [OPTIONS] <reads>
FLAGS:
-x, --fast-mode Calculate depth based only on read starts/stops, see docs for full details
-h, --help Prints help information
-m, --mate-fix Fix overlapping mates counts, see docs for full details
-n, --no-merge Skip merging adjacent bases that have the same depth
-V, --version Prints version information
-z, --zero-base Output positions as 0-based instead of 1-based
OPTIONS:
-B, --bcf-file <bcf-file> A BCF/VCF file containing positions of interest. If specified, only bases
from the given positions will be reported on. Note that it may be more
efficient to calculate depth over regions if your positions are clustered
tightly together
-b, --bed-file <bed-file> A BED file containing regions of interest. If specified, only bases from the
given regions will be reported on
-c, --chunksize <chunksize> The ideal number of basepairs each worker receives. Total bp in memory at one
time is (threads - 2) * chunksize
-F, --exclude-flags <exclude-flags> SAM flags to exclude, recommended 3848 [default: 0]
-f, --include-flags <include-flags> SAM flags to include [default: 0]
-q, --min-mapq <min-mapq> Minimum MAPQ for a read to count toward depth [default: 0]
-o, --output <output> Output path, defaults to stdout
-r, --ref-fasta <ref-fasta> Indexed reference fasta, set if using CRAM
-t, --threads <threads> The number of threads to use [default: 16]
ARGS:
<reads> Input indexed BAM/CRAM to analyze
e
merge-adjacent is a utility to merge overlapping regions in a BED-like file.
It will take a file with four columns and no header as long as the columns are like:
<contig>\t<start>\t<stop>\t<depth>\n
Or it can take files with three columns with headers that are like
<REF|chrom>\t<POS|chromStart>\t<END|chromEnd>\t<DEPTH|COV>
The END|chromEnd column is optional.
Merge adjacent intervals that have the same depth. Input must be sorted like: `sort -k1,1 -k2,2n in.bed > in.sorted.bed`
Generally accepts any file with no header tha is <chrom>\t<start>\t<stop>\t<depth>. The <stop> is optional. See
documentation for explaination of headers that are accepted.
USAGE:
perbase merge-adjacent [FLAGS] [OPTIONS] [in-file]
FLAGS:
-h, --help
Prints help information
-n, --no-header
Indicate if the input file does not have a header
-V, --version
Prints version information
OPTIONS:
-o, --output <output>
The output location, defaults to STDOUT
ARGS:
<in-file>
Input bed-like file, defaults to STDIN
EX:
perbase only-depth indexed.bam | perbase merge-adjacent > out.tsv