ANNOUNCE: PyClimate 1.0

Jon Saenz
Mon, 16 Oct 2000 17:45:43 +0200 (MET DST)

					Monday, 10/16/2000
Hello, all.

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

 6) DCDFLIB.C is currently distributed with the package.

 7) has been converted into a general
    purpose which holds the basic operations
    of any linear filter. There are two different subclasses currently, the
    Lanczos filter and the previous Kolmogorov--Zurbenko filter,
    The user can define new filters just by redefining the filter
    coefficients subclassing LinearFilter.

The package also contains (from release 0.0):
IO functions
-ASCII files (simple, but useful) 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 
	      one call.

Time handling routines
* -> 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.
* -> 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.

EOF analysis
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
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 
Kolmogorov-Zurbenko filter

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 

============ (Europe)   (USA)  (USA)

Any feedback from the users of the package will be really appreciated
by the authors.


Jon Saenz,
Juan Zubillaga,
Jesus Fernandez,

<P><A HREF="">PyClimate 1.0</A> - Several routines for the analysis of climate variability. (16-Oct-00)