fitgcp(1) fit mixtures of probability distributions to genome coverage profiles


fitgcp [options] NAME


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.


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