Calculating Change in 1 dimensional array

2014 8 22
3 个回答
回答已采纳
更新时间：2014 8 22
4 次查看（30 天）

0 个投票

Hello! I have a 1 dimensional array of latitude values (which has dimensions of 1 X 224). How would I calculate the change in latitude, aka delta latitude?
Thank you so much!

请先登录，再回答此问题。

 采纳的回答

Star Strider
Star Strider 2014-8-22

1 个投票

If they are decimal values, use the diff function. Otherwise, you will have to convert them into decimal values (from degrees-minutes-seconds) first.

更多回答（2 个）

Image Analyst
Image Analyst 2014-8-22

1 个投票

Subtract the two latitudes you want to calculate the difference between? Or am I missing something?

2 个评论
显示 无 隐藏 无

I need to calculate the difference between all of the latitudes in the array. For instance, I need to subtract the second from the first latitude, the third from the second latitude, and so on. Does that make sense?
Image Analyst
Image Analyst 2014-8-22
That's what diff() does. Just make sure your angles are in decimal degrees or radians and not some kind of funky degrees/minutes/arcseconds form.

请先登录，再进行评论。

0 个投票

I need to calculate the difference between all of the latitudes in the array. For instance, I need to subtract the second from the first latitude, the third from the second latitude, and so on. Does that make sense?

4 个评论
显示 2更早的评论 隐藏 2更早的评论

Star Strider
Star Strider 2014-8-22
编辑：Star Strider 2014-8-22
It does if it makes sense in the context of your problem. The diff function will do that for you. You have to convert your latitudes to decimal degrees first, though. If you don’t already have a function to do that, this anonymous function will do it:
dms2deg = @(d,m,s) d + m/60 + s/3600;
To convert 45°30' to decimal degrees:
dd = dms2deg(45,30,0);
Image Analyst
Image Analyst 2014-8-22
The diff() function does it for adjacent elements in an entire array, though it will also work on an array of length 2. If you have two arbitrary angles - maybe they're two different variables or two non-adjacent elements in some array - then you'd have to subtract them manually or one at a time.
Do you have the mapping toolbox? Maybe there is some function in there that takes angles in degrees and arseconds and converts to decimal degrees or radians.
Great. Thanks. How would I apply that function (used to convert to degrees) to the entire array and not to just one cell?
Star Strider
Star Strider 2014-8-22
编辑：Star Strider 2014-8-22
According to the online documentation, the Mapping Toolbox has the dms2degrees function that does the same thing. I suggest you use it instead of the one I provided. (I don’t have the Mapping Toolbox, so just now thought to look.)

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Lengths and Angles 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by