December 12, 2019, 01:13:28 am

News:

IonicWind Snippit Manager 2.xx Released!  Install it on a memory stick and take it with you!  With or without IWBasic!


Recent posts

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91
General Questions / Re: Calculating Great Circle B...
Last post by GWS - November 01, 2019, 01:38:46 pm
Hi Egil,

Sounds like you're having fun .. :)

The reason CB is so good at calculations, is that it uses a very simple but ingenious math approach.

All calculations are done to maximum precision, and the results are then rounded to the specified precision.

That's pretty neat :)

Over the years, it's been tested on heavy applications such as seismology, which required 5 dimensional arrays. Hence IonicWind programming systems from CB onwards were developed to be capable of handling arrays of up to 5 dimensions.  Clever stuff .. ;D

Hope you are well ..  :)

Graham
92
General Questions / Re: Calculating Great Circle B...
Last post by Egil - November 01, 2019, 04:11:33 am
Bill,
This morning we made some simulations on the chart machine (Kongsberg) onboard a local trawler. We simulated making a sailing plan for sailing the vessel between here and Tromsoe, along the coast. Then I put the resulting waypoint positions into my own code to see the difference. The legs varied in length from 16 to 128 nautical miles.
The bearings were all exactly the same on both systems, regardless of number of decimals. But the distances varied slightly between the two systems. Then I increased precision with one decimal at the time. From 6 decimals and up, both systems showed exactly the same results.

This was a positive surprise, as I never thought that the CB code was so accurate. Therefore I assume that for more accuracy on longer distances, you have to use more decimals.

In case you want to experiment, I attach the latest Arinc system table. It is transmitted from the mentioned transmitter sites once a year, plus in case any frequency is changed.  This one came when they set up a new transmitter site in Muan, South Korea, ten months ago.
That is where I found the positions, before I converted them into degrees with decimals.
In cas you see  how to improve the calculation routines, please let me know.


Good luck!

Egil
93
General Questions / Re: Calculating Great Circle B...
Last post by billhsln - October 31, 2019, 08:04:10 pm
Interesting.  At least I would assume that the positions given for your transmitter sites won't change, should make things a lot more standard.

Take care,
Bill
94
General Questions / Re: Calculating Great Circle B...
Last post by Egil - October 31, 2019, 04:52:21 pm
Hi Bill,

I've noticed the same thing. And I reckon that where a geo point is set, is more or less up to the people producing maps. The positions I have used in the example, are all the registered positionsm of the Arinc transmitter sites, used for data communications with international flights. And these transmitters are most often located at remote places, far from city centers. But they always use the same name as the nearest city.

When coding the posted example, I set precision to zero, so the rounding errors will in some cases be rather large. But if the positions passed to the distance routine has a greater precision the result will be more accurate.
I have only tested the code with CB, and using ten decimals slowed down the process very much. But for the application I plan to make, I'll only use the code for indicating the course of the decoded flight data, and show it on a map. For this the calculations will be of sufficient accuracy.

But if tanslated to IWB code, the speed should increase noticeably. In fact, that is what I plan to do when I have made all the routines I need, and see that everything works ok.


Egil

95
General Questions / Re: Calculating Great Circle B...
Last post by billhsln - October 31, 2019, 02:37:46 pm
Very interesting.  Have you ever noticed that most sites where you can get Lat and Long seem to differ as to where a city is located.  Looked up Auckland, NZ and your value is different than what I could find from a couple of different sites.  Was wondering how much difference a few points off would make in the distance.

At my work we have a file with info for all the US cities and even it differs from other sites.  I wonder how they determine what they think is the correct value.

Bill
96
General Questions / Calculating Great Circle Beari...
Last post by Egil - October 31, 2019, 07:49:09 am
When I needed formulas for calculating Great circle Bearings and Distances, I first searched the Internet. Just to find that there is a lot of confusion out there about the difference between Great Circle bearings and Rhumb Line bearings. Finally found correct formulas in a book on my own bookshelf! The largest challenge was to get the bearings into the correct quadrants.
And finally, the Atan2 function was posted by GWS (Thanks Graham!). It is slightly rearranged before using it here.


Egil

PS almost forgot to say that the code includes calculations for b3earing and distance f4rom my home to places around the world.
97
User Offerings / Re: IWB key word converter
Last post by LarryMc - October 30, 2019, 07:09:39 am
MessageBox Builder and the ColorPicker tools are built in tools and don't use the tools folder.
The tools folder is only for user added tools.

The reason you found 2 different sets of folders is because to installed IWB 2 different ways which is explained in the TOOLS section of the help file.
98
User Offerings / Re: IWB key word converter
Last post by billhsln - October 29, 2019, 09:18:04 pm
This is very strange, I have 4 IWBdev.ini files, 3 of which say:

help=C:\IWBDev3\help
tools=C:\IWBDev3\tools
help2=C:\IWBDev3\help2

However, when I look under C:\IWBDev3, there is no help, tools or help2 subdirectories.

The other IWBDev3 shows:

help=C:\IWBDev3\help
tools=C:\Users\Bill\AppData\Local\IonicWind\IWBasic3\tools
help2=C:\Users\Bill\AppData\Local\IonicWind\IWBasic3\help2

tools and help2 doesn't exist there either.  Very weird.

Tools do work, tried the MessageBox Builder and the ColorPicker both come up with no problems.  Not sure where their tools exist.

I wonder, are those directories normally blank?  The reason I ask is I ran a program to delete blank directories, which could be why they don't exist?

Bill
99
User Offerings / Re: IWB key word converter
Last post by Andy - October 29, 2019, 04:12:07 am
Bill,

LarryMc is correct, this might help you.

Screenshot 1, locate your IWBDev.ini file.
Where this is, you should see some folders called:

examples
help
templates
tools <------------- this is the folder you want.

In the tools folder (screenshot 2), I have two .inct files:
Constants search.inct
IWB key word case converter.inct <------ this is the entry you need.

I opened it with notepad (screenshot 3).

Code Select
'*NAME|IWB key word case converter
'*USERTOOL|c:\test\subtest\convertkeywords.exe,IWB key word case converter

I renamed it to something else and it disappeared from the tools menu, changed it back and it shows up.

Hope this helps!
Andy.
 :)
100
User Offerings / Re: IWB key word converter
Last post by billhsln - October 28, 2019, 02:33:15 pm
I think I did both, 1 is stored in:

"C:\Program Files (x86)\IWBDev3\bin\IWBDev.exe" - Work version

and the other is in:

C:\IWBDev3\bin\IWBDev.exe - Home version

Looked for an .inct file, don't have any.  What filename should I be looking for.

Thanks,
Bill
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