Thread Subject: attaching datapoints to plot of circle

Hi,

I'm trying to draw a plot of gene promoters along a genome.
These are circular plots, so I've plotted a circle but can't
seem to attach my positions along the circumference. I have
a vector of values that correspond to the position of the
promoters along the genome (from 0 to 2943703) and need a
small tickmark for each of the 387 points, with a bigger
mark for 0 to show the start/end of the genome.

I'm not sure if I'm even going about this the right way or
if I can plot the points along a line using line and set,
etc and then turn the line into a circle somehow?

Any help would be much appreciated....

Colm

Are you drawing a circle as a function of just as a
drawing?
If it's a function, a plot with (x,y) values, you can use
datatips to mark specific regions on the plot.

Here's the thread of the help that I got on doing that
programatically. Thanks again helper!
http://www.mathworks.com/matlabcentral/newsreader/view_thre
ad/168983#431434

Hope this at least gives you a starting point...

Daphne





"Colm " <c.oshea4@nuigalway.ie> wrote in message
<g0hg0a$f4q$1@fred.mathworks.com>...
> Hi,
>
> I'm trying to draw a plot of gene promoters along a
genome.
> These are circular plots, so I've plotted a circle but
can't
> seem to attach my positions along the circumference. I
have
> a vector of values that correspond to the position of the
> promoters along the genome (from 0 to 2943703) and need a
> small tickmark for each of the 387 points, with a bigger
> mark for 0 to show the start/end of the genome.
>
> I'm not sure if I'm even going about this the right way
or
> if I can plot the points along a line using line and set,
> etc and then turn the line into a circle somehow?
>
> Any help would be much appreciated....
>
> Colm

On May 15, 4:49=A0pm, "Daphne " <daphnew_too_nos...@yahoo.com> wrote:
> Are you drawing a circle as a function of just as a
> drawing?
> If it's a function, a plot with (x,y) values, you can use
> datatips to mark specific regions on the plot.
>
> Here's the thread of the help that I got on doing that
> programatically. Thanks again helper!http://www.mathworks.com/matlabcentra=
l/newsreader/view_thre
> ad/168983#431434
>
> Hope this at least gives you a starting point...
>
> Daphne
>
> "Colm " <c.osh...@nuigalway.ie> wrote in message
>
> <g0hg0a$f4...@fred.mathworks.com>...
>
> > Hi,
>
> > I'm trying to draw a plot of gene promoters along a
> genome.
> > These are circular plots, so I've plotted a circle but
> can't
> > seem to attach my positions along the circumference. I
> have
> > a vector of values that correspond to the position of the
> > promoters along the genome (from 0 to 2943703) and need a
> > small tickmark for each of the 387 points, with a bigger
> > mark for 0 to show the start/end of the genome.
>
> > I'm not sure if I'm even going about this the right way
> or
> > if I can plot the points along a line using line and set,
> > etc and then turn the line into a circle somehow?
>
> > Any help would be much appreciated....
>
> > Colm

All the points on the circle can be said as "Points which are r
distance away from the centre" where r is the radius of circle you
have drawn. Now you have mentioned 387 points which according to my
understanding all are on the circle and r distance away from centre.
All you need to know is angle which can be obtained from x and y
coordinates and then you can find a grid point which satisfies angle
and radius pair.
As you said the points range from 0 to 2943703. This range might be
helpful in deciding on angle, size of point.
You might have to explain a little bit of background for these 387
points and is there any other information about them. Might be time
you got the value or they are in sequence starting with 0 degree and
going to 360 with some interval.

"Colm " <c.oshea4@nuigalway.ie> wrote in message <g0hg0a$f4q
$1@fred.mathworks.com>...
> Hi,
>
> I'm trying to draw a plot of gene promoters along a genome.
> These are circular plots, so I've plotted a circle but can't
> seem to attach my positions along the circumference. I have
> a vector of values that correspond to the position of the
> promoters along the genome (from 0 to 2943703) and need a
> small tickmark for each of the 387 points, with a bigger
> mark for 0 to show the start/end of the genome.
>
> I'm not sure if I'm even going about this the right way or
> if I can plot the points along a line using line and set,
> etc and then turn the line into a circle somehow?
>
> Any help would be much appreciated....
>
> Colm
----------
  I am guessing this is what you want. Let v be the vector of 387 values that
range from 0 to 2943703.

 a = v/2943704*2*pi;
 x = cos(a); y = sin(a);
 t = linspace(0,2*pi,1000)
 X = cos(t); Y = sin(t);
 plot(X,Y,'y-',x,y,'r*')

The asterisks will appear on the circle's positions that correspond to the
positions of your promoters.

  You will have one problem. The number of asterisks, 387, is rather large to
be depicted meaningfully on a single circular screen plot. I would think you
would want to show them in something like a raster-like arrangement that
could give more meaning to their individual positions. If there were, say, 80
lines across, then each line would have only 5 promoters on average.

Roger Stafford