ANNOUNCE: PyClimate 1.0
Mon, 16 Oct 2000 17:45:43 +0200 (MET DST)
We are making the first announce of the first stable release (1.0) of
our package pyclimate, which presents some tools used for climate
variability analysis and which make extensive use of Numerical Python
and C. It is released under the GNU Public License.
Changes from the previous release
Version 1.0--October, 2000.
1) Improved tests. They are more accurate, reliable, informative,
comprehensive and use less disk space.
2) The package compiles using distutils.
This feature has been checked on FreeBSD, Linux and OSF platforms.
3) Some minor typos corrected in the documentation.
4) Added KPDF.c, a extension module to estimate univariate
and multivariate kernel--based probability density functions.
5) Added a class to compute the vertical component
of the curl of a vectorial field in diffoperators.py.
6) DCDFLIB.C is currently distributed with the package.
7) KZFilter.py has been converted into a general
purpose LinearFilter.py which holds the basic operations
of any linear filter. There are two different subclasses currently, the
Lanczos filter and the previous Kolmogorov--Zurbenko filter, KZFilter.py.
The user can define new filters just by redefining the filter
coefficients subclassing LinearFilter.
The package also contains (from release 0.0):
-ASCII files (simple, but useful)
-ncstruct.py: netCDF structure copier. From a COARDS compliant netCDF
file, this module creates a COARDS compliant file,
copying the needed attributes, comments, and so on in
Time handling routines
* JDTime.py -> Some C/Python functions to convert from date to Scaliger's
Julian Day and from Julian Day to date. We are not trying to
replace mxDate, but addressing a different problem.
In particular, this module contains a routine
especially suited to handling monthly time steps
for climatological use.
* JDTimeHandler.py -> Python module which parses the units
attribute of the time variable in a COARDS
file and which offsets and scales adequately
the time values to read/save date fields.
Interface to DCDFLIB.C
A C/Python interface to the free DCDFLIB.C library is provided. This library
allows direct and inverse computations of parameters for several
probability distribution functions like Chi^2, normal, binomial, F,
noncentral F, and many many more.
Empirical Orthogonal Function analysis based on the SVD decomposition of
the data matrix and related functions to test the reliability/degeneracy
of eigenvalues (truncation rules). Monte Carlo test of the stability
of eigenvectors to temporal subsampling.
SVD decomposition of the correlation matrix of two datasets, functions
to compute the expansion coefficients, the squared cumulative covariance
fraction and the homogeneous and heterogeneous correlation maps.
Monte Carlo test of the stability of singular vectors to temporal
Multivariate digital filter
Multivariate digital filter (high and low pass) based on the
Differential operators on the sphere
Some classes to compute differential operators (gradient and divergence)
on a regular latitude/longitude grid.
GNU General Public License Version 2.
To be able to use it, you will need:
1. Python ;-)
2. netCDF library 3.4 or later
3. Scientific Python, by Konrad Hinsen
IF AND ONLY IF you really want to change the C code (JDTime.[hc] and
pycdf.[hc]), then, you will also need SWIG.
Now, we use distutils. The installation is simpler.
Postscript and PDF versions of the manual are included in the
distribution. We are preparing an even better version of the
Any feedback from the users of the package will be really appreciated
by the authors.
Jon Saenz, firstname.lastname@example.org
Juan Zubillaga, email@example.com
Jesus Fernandez, firstname.lastname@example.org
<P><A HREF="http://starship.python.net/crew/jsaenz/pyclimate">PyClimate 1.0</A> - Several routines for the analysis of climate variability. (16-Oct-00)