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From: DRG on 1 Mar 2010 14:52
Hey all;

I have a 1 x 360 array of a function I have computed in one degree
increments from a model in the lab. I want to use matlab to display
this in a circular plot to show varying intensity with angular
displacement, however I cannot seem to get my function to work
properly with the polar plot function; I should have one full circle
of values with one every one degree, however polar plot does not seem
to do this at all. I suspect my argument should be in radians instead
of degrees but surely there is a way to get it to display my data in a
circular diagram ? The data has a max of 60.5 and a min of 8.1..

Thanks in advance..
From: Walter Roberson on 1 Mar 2010 14:51
DRG wrote:

> I have a 1 x 360 array of a function I have computed in one degree
> increments from a model in the lab. I want to use matlab to display
> this in a circular plot to show varying intensity with angular
> displacement, however I cannot seem to get my function to work
> properly with the polar plot function; I should have one full circle
> of values with one every one degree, however polar plot does not seem
> to do this at all. I suspect my argument should be in radians instead
> of degrees but surely there is a way to get it to display my data in a
> circular diagram ? The data has a max of 60.5 and a min of 8.1..

Yes, you need to provide radians instead of degrees for the angles for polar
plots. You can use

degreestoradians = linspace(0,2*pi,361);

then provide the polar() function with either degreestoradians(1:end-1) or
degreestoradians(2:end) depending on whether you want your first point to be
at angle 0 degrees (ending at 359) or if you want your first point to be at
angle 1 degree (ending at 360).
From: DRG on 2 Mar 2010 12:08
Thanks Walter.. that still doesn't seem to be working for me though;
It now displays something but not what it should. Surely there should
be a single value at every angular position from 0 - 360 if it's
working right ? It seems to repeat the values a lot and instead of
having single points, it goes over itself and has a spider web effect.
Any ideas?

On Mar 1, 7:51 pm, Walter Roberson <rober...(a)hushmail.com> wrote:
> DRG wrote:
> >  I have a 1 x 360 array of a function I have computed in one degree
> > increments from a model in the lab. I want to use matlab to display
> > this in a circular plot to show varying intensity with angular
> > displacement, however I cannot seem to get my function to work
> > properly with the polar plot function; I should have one full circle
> > of values with one every one degree, however polar plot does not seem
> > to do this at all. I suspect my argument should be in radians instead
> > of degrees but surely there is a way to get it to display my data in a
> > circular diagram ? The data has a max of 60.5 and a min of 8.1..
>
> Yes, you need to provide radians instead of degrees for the angles for polar
> plots. You can use
>
> degreestoradians = linspace(0,2*pi,361);
>
> then provide the polar() function with either degreestoradians(1:end-1) or
> degreestoradians(2:end) depending on whether you want your first point to be
> at angle 0 degrees (ending at 359) or if you want your first point to be at
> angle 1 degree (ending at 360).

From: Lorenzo Guerrasio on 2 Mar 2010 12:23
COuld you provide some lines representing your code?
It is difficoult to understand what it might be wrong,otherwise.

DRG <grimesd2(a)gmail.com> wrote in message <13e90a7d-268f-4ace-81e2-5b8bcec973cb(a)m37g2000yqf.googlegroups.com>...
> Thanks Walter.. that still doesn't seem to be working for me though;
> It now displays something but not what it should. Surely there should
> be a single value at every angular position from 0 - 360 if it's
> working right ? It seems to repeat the values a lot and instead of
> having single points, it goes over itself and has a spider web effect.
> Any ideas?
>
> On Mar 1, 7:51 pm, Walter Roberson <rober...(a)hushmail.com> wrote:
> > DRG wrote:
> > >  I have a 1 x 360 array of a function I have computed in one degree
> > > increments from a model in the lab. I want to use matlab to display
> > > this in a circular plot to show varying intensity with angular
> > > displacement, however I cannot seem to get my function to work
> > > properly with the polar plot function; I should have one full circle
> > > of values with one every one degree, however polar plot does not seem
> > > to do this at all. I suspect my argument should be in radians instead
> > > of degrees but surely there is a way to get it to display my data in a
> > > circular diagram ? The data has a max of 60.5 and a min of 8.1..
> >
> > Yes, you need to provide radians instead of degrees for the angles for polar
> > plots. You can use
> >
> > degreestoradians = linspace(0,2*pi,361);
> >
> > then provide the polar() function with either degreestoradians(1:end-1) or
> > degreestoradians(2:end) depending on whether you want your first point to be
> > at angle 0 degrees (ending at 359) or if you want your first point to be at
> > angle 1 degree (ending at 360).
From: Walter Roberson on 2 Mar 2010 13:13
DRG wrote:
> Thanks Walter.. that still doesn't seem to be working for me though;
> It now displays something but not what it should. Surely there should
> be a single value at every angular position from 0 - 360 if it's
> working right ? It seems to repeat the values a lot and instead of
> having single points, it goes over itself and has a spider web effect.
> Any ideas?

You could get that effect if any of the values to be plotted are
negative or complex, or if you reversed the order of the parameters.

Beyond that... a bit later I'll do a small experiment to verify that my
logic was correct (I'm not by my matlab machine at the moment.)
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