This is the command wzip that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
wzip - lossy data compression and denoising
SYNOPSIS
wzip [ -c | -d | -dn | -hdn ] num sf
DESCRIPTION
This manual page documents the wzip command.
wzip is a program that can be used for LOSSY data compression and denoising. It reads
from STDIN and writes to STDOUT. In compression mode the input is a sequence of ascii
floating-point values. num is the number of these data values. The output is a sequence
of small integers, most of them zero in typical application. This is ready for effective
compression with a standard loss-less compression program like gzip.
The program can also be used for denoising. In this case both input and output are
sequences of ascii floating-point values.
The scale factor sf determines the strength of compression or denoising. A higher scale
factor means heavier compression and stronger denoising. Four times the standard
deviation of the noise content is a good start. Otherwise 5 percent of the overall signal
amplitude might be used as a first estimation of a suitable scale factor.
If the noise content of the input data is strongly non-Gaussian-distributed, like Poisson
noise. The input data should be transformed to approximate Gaussian-distributed noise. If
the input values are Poisson-distributed, that means for example raw counts per channel in
EDX or XPD, they can be transformed to approximate Gaussian-distributed noise by
transformation of each data point with y:=2.0*sqrt(x+0.25109). Back transformation is done
with y:=(x/2)^2. The summand 0.25109 compensates for the bias caused by the asymmetry of
the Poisson-distribution.
Invoking the program without any options writes examples of the use of the program to
STDERR.
OPTIONS
There must be given exactly one option.
-c Compression, reads num ascii floating-point values from STDIN and writes a sequence
of integers with high redundancy to STDOUT.
-d Decompression, reads from STDIN and writes a sequence of num ascii floating-point
values to STDOUT. These are more or less similar to the original data.
-dn Denoising, reads num ascii floating-point values from STDIN and writes a sequence
of num ascii floating-point values to STDOUT. These are more or less similar to the
original data.
-hdn Denoising with hard thresholding instead of wavelet shrinkage. Single untouched
noise peaks may be visible with this mode. On the other hand, there is much less
impact on the signal slope.
Use wzip online using onworks.net services
