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Changes in dlnm 2.0.0 (10 Sept 2013) : further info
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Since version 2.0.0, the dlnm package includes important changes. These changes 
affect the usage of code developed for older versions. In particular, some
default values in the functions crossbasis() and onebasis() are now different, 
and the use of code for versions between 1.5.1 and 2.0.0 can generate different
results with the new version, although a warning is returned. Also, the usage of
versions older than 1.5.1 does not work anymore. 
See below for details.

The function onebasis() is now a wrapper for other existing functions, and also 
its syntax has slightly changed. In particular, the default values for the
arguments are now those of the called functions themselves. The new functions
strata(), poly(), lthr() and integer() are now available, which with ns() and 
bs() in the package splines now offer all the options available earlier. Other
existing or user-defined functions can be applied to extend the framework.

The functions crossbasis() calls onebasis() internally, and the same changes
apply to it. An important change is that the knots for the spline functions or 
cut-offs for strata in the lag dimension are now placed at equally-spaced
percentiles if not specified, differently from the default in previous versions.
This implies that code produced for versions earlier than 2.0.0 generates
different results with the new versions. The new function logknots() has been
added for placing the knots at equally-spaced values in the log scale, the
default previously used.

The syntax for the old versions still works in many other cases, and changes are
included internally when possible. However, results can now be different when
using the default knots placement. The functions do not anymore return any
warning about the new syntax.

An updated version of code published in various articles is available at:
www.ag-myresearch.com

Detailed info on changes are provided in:
file.show(system.file("ChangeLog",package="dlnm"))

These changes have been included for consistency and were unavoidable. The
authors apologize for the inconvenience.
Please report any issue with the new version to:
antonio.gasparrini@lshtm.ac.uk

For general info on the package, type help(dlnm) and vignette('dlnmOverview')