NAME¶fitgcp - fit mixtures of probability distributions to genome coverage profiles
SYNOPSIS¶fitgcp [options] NAME
DESCRIPTION¶Fits mixtures of probability distributions to genome coverage profiles using an EM-like iterative algorithm.
The script uses a SAM file as input and parses the mapping information and creates a Genome Coverage Profile (GCP). The GCP is written to a file, such that this step can be skipped the next time. The user provides a mixture model that is fitted to the GCP. Furthermore, the user may specify initial parameters for each model.
As output, the script generates a text file containing the final set of fit parameters and additional information about the fitting process. A log file contains the the current set of parameters in each step of the iteration. If requested, a plot of the GCP and the fitted distributions can be created.
OPTIONS¶NAME: Name of SAM file to analyze.
- -h, --help
- show this help message and exit
- -d DIST, --distributions=DIST
- Distributions to fit. z->zero; n: nbinom (MOM); N: nbinom (MLE); p:binom; t: tail. Default: zn
- -i STEPS, --iterations=STEPS
- Maximum number of iterations. Default: 50
- -t THR, --threshold=THR
- Set the convergence threshold for the iteration. Stop if the change between two iterations is less than THR. Default: 0.01
- -c CUTOFF, --cutoff=CUTOFF
- Specifies a coverage cutoff quantile such that only coverage values below this quantile are considered. Default: 0.95
- -p, --plot
- Create a plot of the fitted mixture model. Default: False
- -m MEAN, --means=MEAN
- Specifies the initial values for the mean of each Poisson or Negative Binomial distribution. Usage: -m 12.4 -m 16.1 will specify the means for the first two non-zero/tail distributions. The default is calculated from the data.
- -a ALPHA, --alpha=ALPHA
- Specifies the initial values for the proportion alpha of each distribution. Usage: For three distributions -a 0.3 -a 0.3 specifies the proportions 0.3, 0.3 and 0.4. The default is equal proportions for all distributions.
- -l, --log
- Enable logging. Default: False
- Only view the GCP. Do not fit any distribution. Respects cutoff (-c). Default: False
|February 2014||fitgcp 2013-04-18|