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[1]<- Previous [2]Contents
Icon News
__________________________________________________________________
XTide 2.9.5
XTide 2.9.5 is all portability fixes. A case-sensitive file name clash
was removed, and the command-line client now compiles under Visual
C++. XTide 2.9.5 is available for downloading from
[3]http://www.flaterco.com/xtide/files.html#xtide.
FAQ of the Day: "Are these predictions compliant with the new 2007 Daylight
Savings Time rules for the U.S.?"
XTide relies on [4]the de facto standard time zone database to handle
Daylight Savings Time. XTide's results will obey the new Daylight
Savings Time rules if and only if the version of zoneinfo installed is
sufficiently new. See [5]System Requirements.
Harmgen 3
Harmgen, the package for deriving harmonic constants from water level
observations, has been renovated and its integration with Congen and
Harmbase has been improved. Get it at
[6]http://www.flaterco.com/xtide/files.html#experts.
Congen 1.6
Congen 1.6 is a complete rewrite of the package for generating the
speeds, equilibrium arguments, and node factors of tidal constituents.
In addition to the classic command-line interface provided by Congen
1.5, it now includes a C++ library that can be used directly by other
programs. Get it at
[7]http://www.flaterco.com/xtide/files.html#experts.
tideEditor 1.4.1
Changes in tideEditor 1.4 include the ability to view and edit all
fields in the latest harmonics file and improved error checking. Get
it at [8]http://www.flaterco.com/xtide/files.html#extras.
PHP Special Interest Group
A number of people have expressed interest in getting XTide to work
through PHP. Thus far I have just been introducing them to each other
through e-mail and waiting for cool things to happen. There is now a
[9]WordPress plugin by Mir Rodrguez.
Native OS X port
Lee Ann Rucker has done a nativized port to OS X using [10]Cocoa and
Objective-C. It is available at
[11]http://homepage.mac.com/lrucker/XTide/.
Mailing list
There is a manually-maintained, announce-only mailing list to which I
send notices of each update to XTide or the harmonics data. You can
request to join by e-mailing me at dave@flaterco.com.
__________________________________________________________________
Roadmap to future development
Things worth fixing / TO-DO list
General
* Relicense everything as [12]GPLv3.
* Purge copies of Dstr
Data maintenance
There is great demand for a centrally maintained, royalty-free,
authoritative database of all tide stations in a standardized format.
Such a database does not exist.
It takes a great deal of effort on my part to scrape tide data from
interactive web sites and transform them into a coherent database for
use with XTide. That database is then used by numerous projects, both
open source and commercial, because it is the closest thing to a
centrally maintained, royalty-free, authoritative database that is
available. I do not get paid to do this. It's a huge amount of work
with a steep learning curve attached, and nobody else will do it.
As onerous as it is just to update the data for the U.S. once a year, I
cannot afford to import and maintain any data whose quality is suspect
or where no reliable source for future updates exists; nor can I afford
to engage in activism to try to persuade tide authorities to release
more data.
All of the tools that I use are open source and available for download
from [13]http://www.flaterco.com/xtide/files.html. The Tide
Constituent Database (TCD) library is even public domain. I hope that
someday tide authorities will use it to produce TCD files that they
distribute directly, and then my role in this will become redundant.
* Refresh NOS data when NOS posts 2008 tables
+ Update renamings
+ Do 100% check of reference stations
+ Check Portland, Morrison Street Bridge, Oregon for changes in
behavior
* Either get more German data or regenerate using the old data and
fewer constituents
* Maybe create a currents database using legacy constants + new
offsets, for lack of something better
* Maybe scrape the simplified harmonic constants from the Norwegian
Hydrographic Service--acceptable use TBD
* Lots of inactive Canadian stations might be usable
xtide
* Investigate [14]pcal interoperability problem. Why won't it import
iCal?
libtcd
* Things not to do unless/until a major revision is needed.
+ Get rid of internal state; fix inability to have more than one
database open
+ Remove gratuitous complexity in the encoding of speeds,
equilibrium arguments, and node factors; make speeds 32-bit
unsigned with no offset
+ Possibly permit node factors to be specified for intervals
shorter than 1 year or support apps that use libcongen to
generate the node factors themselves
tcd-utils
* Fix truncation of notes by build_tide_db
* build_tide_db recognize datumkind field name
Harmbase2
* Clean up the code.
* Resolve inconsistent handling of Canada vs. subordinate stations
based on U.S. reference stations.
Suggested XTide features and other etceteras
The following features have been suggested or thought about but did not
make the cut. They could be added in future revisions if there were
sufficient demand.
* There ought to be a way to specify relative dates and times in the
-b and -e fields. Need an applicable standard; ISO 8601 doesn't
support it. Simon Bridger requested -b and -e to recognize
relative specifications like yesterday, today, tomorrow, mon-sun,
sat+7 for next Saturday, "tomorrow 23:59" or "sat 00:00". Others
want to specify a small relative offset from the current time for
-b to change the position of the + mark in graphs.
* Factor out a standalone component library as a favor to developers
who want to reuse XTide's engine but reinvent its wheels.
* Generate maps for xttpd navigation and general illustration,
include in LaTeX form.
* Graeme Rae suggested a line for the current time in text listings,
like "2001-03-19 11:50 AM PST 0.10 feet Falling." This is doable
now that the tide events code has been refactored, but it's not
clear what the settings and behaviors should be to handle the "now"
event consistently across all modes. Graphs and clocks have their
own ways of showing the "now," and it would be inappropriate to
include "now" in a calendar.
* Simon Bridger requested support for multiple -b and -e
specifications.
* Tim Cera notes that Options might be more user-friendly if it was
split into separate menus for "Create new windows" versus "Change
settings."
* Add a real color chooser in control panel. This would come free
with Qt or similar if we ever migrated from Athena widgets.
* Constituent inference was patched in via libtcd and maybe could
have been integrated better. In theory, you might want to control
it on a station-by-station basis like preferred units. But, maybe
it's a non-issue. Nobody has complained yet.
* Generate node factors and equilibrium arguments more than once a
year. Most tide prediction software does it monthly or at least
does it for the middle of your prediction interval. But the legacy
of SP98 is to do it yearly.
* Add support for Doodson style tide prediction as used by Foreman's
IOS package. At this time there seems to be little benefit to be
gained by doing this:
1. No new Doodson data appear to be forthcoming.
2. Most Doodson constituents are approximated fairly well by
Congen now.
3. The ones that aren't approximated well are those that are
drastically affected by latitude. To support
latitude-dependent constituents, node factors and equilibrium
arguments would have to be generated internally to XTide,
which would be a significant architectural change.
4. Casement opined that the latitude-dependent method is bogus
anyway because tides are generated some place in mid-ocean
with a different latitude.
5. If you want IOS, you can find it at
[15]http://www.pac.dfo-mpo.gc.ca/sci/osap/projects/tidpack/tid
pack_e.htm.
* Simon Bridger requested a "weekend warrior" option that lists
today, tomorrow, Saturday, Sunday, and next Saturday.
* Jef Poskanzer long ago asked for a global plot of tide levels to
show how the tides move around. This could be done by color-coding
the dots on the globe, but it would (1) require a true-color
display and (2) be too slow to be the default behavior of the
globe. Hans Bot has seconded this request.
* David Mendez suggests plotting the derivative of the tide as well
as the tide--this is useful for predicting swells.
* Diane Grant wants to be able to execute a query like 'find all days
in this year having a flood greater than 3.0 between 8 AM and 9
AM.'
* xttpd: Change mapping of locations to URLs so that links won't
break when harmonics files are changed. Thought about this but
could not find a better solution than putting the entire location
name in the URL, which is already semi-supported by the exact query
feature.
__________________________________________________________________
[16]<- Previous [17]Contents
References
1. http://www.flaterco.com/xtide/changelog.html
2. http://www.flaterco.com/xtide/xtide.html#contents
3. http://www.flaterco.com/xtide/files.html#xtide
4. ftp://elsie.nci.nih.gov/pub/
5. http://www.flaterco.com/xtide/sysreq.html#TZsysreq
6. http://www.flaterco.com/xtide/files.html#experts
7. http://www.flaterco.com/xtide/files.html#experts
8. http://www.flaterco.com/xtide/files.html#extras
9. http://www.almanaqueazul.org/?p=132
10. http://developer.apple.com/cocoa/
11. http://homepage.mac.com/lrucker/XTide/
12. http://gplv3.fsf.org/
13. http://www.flaterco.com/xtide/files.html
14. http://pcal.sourceforge.net/
15. http://www.pac.dfo-mpo.gc.ca/sci/osap/projects/tidpack/tidpack_e.htm
16. http://www.flaterco.com/xtide/changelog.html
17. http://www.flaterco.com/xtide/xtide.html#contents
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