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Old 07-09-2013, 14:17   #16
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Re: WxRouting- QtVlm or the plugin.

In trying to find the "Comp.7z" file and the Polar that Cagney used for his test
WxRouting- QtVlm or the plugin.

I checked my downloads directory, found "Comp.7z" and polar file "boat_Mono650.csv" I discovered that that file is as follows:
Quote:
<?xml version="1.0" encoding="utf-8" ?>
<OCPNWeatherRoutingBoat version="0.8" creator="Opencpn Weather Routing plugin">
<BoatCharacteristics displacement_tons="4" lwl_ft="24" loa_ft="27" beam_ft="8" />
<BoatDrag frictional_drag="0.0000" wake_drag="0.0000" />
<Plan Name="Initial Plan" computed="1" eta="0.2500" luff_angle="15.0000" />
</OCPNWeatherRoutingBoat>
I believe this downloaded file named "Mono_650" is for a 27' Bristol (Sean's boat) it is the same as the default file used by Weather_routing_pi VPP polar generator. Since this file was provided by Cagney, via download, and I believe it does not correspond with the "Mono_650" in qtVlm, it seems to be readily apparent that we are not comparing apples to apples. Therefore I believe that previous runs are not comparable. This may be the reason Cagney was noticing trouble getting a polar that goes up to 7-8 knots (above).

Note:
I've been noticing that Weather_routing does not retain the settings for polars, so they have to be reloaded. Also I believe the plugin does not "save" polars properly, because "saved" polars do not seem to open without an error.
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Old 07-09-2013, 14:52   #17
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Re: WxRouting- QtVlm or the plugin.

Find the boat_Mono650.csv Polar here Index of /Polaires

Tracker Bug Report for the WeatherFax plugin.

FS#117 - Fix saving and loading polar files and Boat VPP Specs. We also need to know what file is being used, so that should appear somewhere I think, and know it is not changed or overwritten inadvertantly without us intitiating it.
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Old 07-09-2013, 16:06   #18
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Re: WxRouting- QtVlm or the plugin.

Yes that's correct. The Mono_650.csv was corrupt on my computer. It was copied from qtVlm, but changed somehow along the way ....
I can't do a new test, for the moment, as the plugin/OpenCPN crashes when I'm trying to load a new copy of the polars. Clearly, more comparing tests are needed.

Thomas
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Old 07-09-2013, 18:56   #19
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Re: WxRouting- QtVlm or the plugin.

Weather_routing has a lot of nooks and crannies I have not explored and do not fullly understand. However it is becoming apparent we need to get a handle on Polars to run some tests. ... to that end.


Tracker above is FS#1117.
I've been messing about with the settings under Configuration > Edit "Boat" Edit button. There aree 5 tabs:
Plot Details, Polar File, VMG, Hull, Sail Plan, Statistics
Each of these tabs is packed with settings and information.

Plot Details Tab - has file save, save as, open & close (it would be helpful if the path was remembered). Selection of boat, apparent & true. Wind Knots adjustment, and Signif Wave Ht & Wave period. When you set these settings and Save as, then bring it back in with Open, the wind knots do not change, just the Boat, Apparent, True.
I a still not quite sure what these XML files are supposed to do, they have this form:
OCPNWeatherRoutingBoat
BoatCharacteristics () Boatcharacteristics
BostDrag () BoatDrag
Plan () Plan
OCPNWehaterRoutingBoat

Polar File Tab


When I bring is a well formatted polar from qtVlm called boat_Mono650.csv It loads fine and the polar seems to be ok. When I save it out to a new name and then Open that file, all the polar curves are gone. This is a bug.

VMG Tab


I don't understand what Optimize Tacking does. It seems to affect the areas directly upwind in unrealistic ways.

Hull Tab
Type of hull - disp tons lwl ft.
These settings can be saved I think.
Drag frictional wake then recompute Info
The info tab is helpful.

Sail Plan Tab
We could use another Info tab here explaining.
I think Eta is some factor for sailing efficiency, no boat is 100% efficient, it is a way of matching reality (seaweed, barnacles, seaway, waves, sail set, etc. to the polar) When Eta goes down the speed goes up.
There is also a Max point angle setting for the boat, and New and Edit buttons. I belive Ocpn bombs when I hit these two buttons. I have sent several crash messages so far.

Statistics Tab
Has beam, loa feet with resulting hull speed, capsize, comfort, etc. When the window is closed the Beam number is NOT saved and always has to be redone!! This is a bit of a pain.

---
Comment about
VPP Polars from Boat data VS Opening a Polar File.
When we open a polar file, should we NOT touch anything else or the file is changed? Should we stay out of the VPP tabs so things are not changed and rewrittten? I think this needs to become clearer to the user and perhaps structurally built into the program.
One side is opening a polar, the other side is calc polar from the boat data.
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Old 09-09-2013, 06:31   #20
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Re: WxRouting- QtVlm or the plugin.

Maitai reports qtVlm Version 3.4.1 has been released.

Please note that qtVlm download site has moved to QtVlm Download

Apart from many small and not-so-small bug fixes, it mainly has:

-An improved routing module
-An option for calculating automatically several routing at different dates/hours, in order to find the best departure date/time
-An option to compare several routes
-An option for displaying day/night zones
-A new skinable dashboard (VLM mode only)
-Support for Sarana, RTOFS and COAMP grib files
-Grib color values are now configurable
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