[x]
Posted via EE Mobile

Search, ask, and monitor your questions on the go with EE Mobile. Visit Experts Exchange from your mobile device and never be out of touch again.

03/22/2008 at 02:40PM PDT, ID: 23261935
[x]
Attachment Details
[x]
The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

  • The Grade of the Solution
  • The Zone Rank of the Expert Providing the Solution
  • The Number of Author and Expert Comments
  • The Number of Experts Contributing
  • The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!

8.0

Draw an arrow on a sphere.

Asked by PaulCaswell in Math & Science

Hi all,

Got an interesting one.

I want to draw an arrow between two points using kml in Google Earth.

Using planar coordinates the calculation looks right if I do it like this:

Line: (x1,y1),(x2,y2)

w = 0.1 (Width of the shaft of the arrow (for example))
n = 2 (Number of w's the point of the arrow should extend (for example))
x = x2 - x1 (Extent of line in x direction)
y = y2 - y1 (Extent of line in y direction)
d = sqrt((x*x)+(y*y)) (Length of line)
wx = y * wy / x (Extent of shoulder in x direction)
wy = w * x / d (Extent of shoulder in y direction)
nw = n * w (Length of point)
nwx = nw * x / d (Extent of point in x direction)
nwy = y * nwx / x (Extent of point in y direction)

The coordinates of the arrow look like this:

(x1-wx,y1-wy)
(x1+wx,y1+wy)
(x2-nwx+wx,y2+nwy+wy)
(x2-nwx+wx+wx,y2+nwy+wy+wy)
(x2,y2)
(x2-nwx-wx-wx,y2+nwy+wy+wy)
(x2-nwx-wx,y2+nwy+wy)
(x1-wx,y1-wy)

When I place this arrow in google earth it looks 'skewed'. I have attached a sample kml file to look at. Just open Google Earth and paste it from a text editor.

I am guessing I am not taking into account the fact that the coordinates in kml are spherical.

What changes do I need to make to the calculations to make it look better in Google Earth?

Paul
Attachments:
 
KML For an arrow.
 
[+][-]03/26/08 12:40 AM, ID: 21209494

View this solution now by starting your 30-day free trial. Setting up your free trial is quick, easy, and secure. We will return you to this solution, unlocked, when you're done.

 

About this solution

Zone: Math & Science
Sign Up Now!
Solution Provided By: ozo
Participating Experts: 2
Solution Grade: A
 
 
[+][-]03/22/08 02:53 PM, ID: 21187860

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]03/22/08 03:29 PM, ID: 21187952

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]03/23/08 04:20 AM, ID: 21189260

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]03/23/08 05:42 PM, ID: 21191254

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]03/24/08 05:49 AM, ID: 21193165

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]03/24/08 10:38 AM, ID: 21195151

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]03/24/08 11:45 AM, ID: 21195735

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]03/25/08 11:41 PM, ID: 21209285

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]03/26/08 12:10 PM, ID: 21215102

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]08/28/08 02:22 AM, ID: 22332896

Experts Exchange has a courteous staff of administrators who help members get the most out of the website by means of administrative comments like this one.

Start your 30-day free trial to view this Administrative Comment or ask the Experts your question.

 
 
Loading Advertisement...
20091028-EE-VQP-86 / EE_QW_2_20070628