*PLOT FIELD VECTOR*
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(sin(4*x+8*y),cos(4*x+8*y),0)
16 Comments
Image Analyst
on 19 Dec 2011
Yeah, so? How about you explain something in English rather than just display a bunch of code? If there's a problem with quiver or inline, have you tried to figure it out by looking up the arguments and examples in the help? If you got an error, why didn't you post the error???
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
I misread the original code; sub2ind() was not an appropriate solution.
What error message did you get originally? The sizes look okay to me when I work them through mentally.
Naz
on 19 Dec 2011
I used the code you posted and did not get any errors
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
It would save time if you were to post the error message that *you* encountered, or at least describe what the difference was between the output you got and the output you expected?
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
You want to find the surface area of a quiver plot??
What exactly are you asking us in this question? Are you encountering an error in the code you posted?
If you were asking us about how to find the area surface limit x,y,z then your code would have to have z in it somewhere. The closest you show is your F, which is only 2D, and "surface area" is not a phrase that is applied to a 2D object (the 2D term is just "area")
Do not just post code and expect us to know what you want to do!
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
Okay, so you have defined an x, y, and z, and you have indicated that you need to use quiver(). You have not, though, indicated what is to be done. quiver() requires an x and y (but not a z), and it requires two vector fields, u and v. You do not have enough variables defined, not unless you want to use quiver(x,y) with the x and the y acting as u and v matrices.
http://www.mathworks.com/help/techdoc/ref/quiver.html
Are you certain that you want to write the value sin(4*x+8*y) over top of x? And then to use the new x in calculating cos(4*x+8*y) that you then write over the old y ?
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
I see you have edited your code, but you have not yet indicated what is to be done. What is the relationship between the F matrix and the quivers to be drawn? For the quiver() call you need an "x", a "y", a "u" and a "v" parameter: do the "x" and "y" parameters you wish to use correspond to your "x" and "y" variables?
justin Taylor
on 19 Dec 2011
Naz
on 19 Dec 2011
Can you edit your question and provide all information that is given to you as well as requirements?
justin Taylor
on 19 Dec 2011
Walter Roberson
on 19 Dec 2011
You removed all the useful information from your question...
Accepted Answer
Walter Roberson
on 21 Dec 2011
>> t = linspace(0,4*pi,100);
>> [x,y] = ndgrid(t,t);
>> u = sin(4*x+8*y);
>> v = cos(4*x+8*y);
>> quiver(x,y,u,v)
4 Comments
justin Taylor
on 22 Dec 2011
Walter Roberson
on 22 Dec 2011
I spend so much time working that I reserve my facebook account for communication that has nothing to do with work, such as chatting with my large number of cousins.
justin Taylor
on 22 Dec 2011
justin Taylor
on 24 Dec 2011
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on 19 Dec 2011
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