annotation in polarplot

I searched to annotate the polar plot, which needs normalized figure units. For Cartesian, we have a nice solution. This is the best solutio

clc; clear all;

% Dr Kaluri V Ranga Rao life senior member IEEE princeton [e-mail]

close all;

theta = linspace(0,360,180);

max = 1;

r = linspace(max,0.2,180);

s = 60; e = 20;

ra = [r(s) r(e)];

th = [theta(s) theta(e)];

h = polarplot(theta*pi/180,r,'.-r',th*pi/180,ra,'ob');

for k=1:180

[xaf,yaf] = polarDS2nfu([theta(k) theta(k)]*pi/180,[r(k)*0.5 r(k)]);

hT = annotation('arrow',xaf,yaf);

pause(0.5);

end

function varargout = polarDS2nfu(varargin)

% polarDS2nfu Convert data space polar units into normalized figure units.

%

% [Xf, Yf] = DS2NFU(X, Y) converts X,Y are theta,r polar coordinates from

% data space to normalized figure units, using the current axes. This is

% useful as input for ANNOTATION.

%

% POSf = DS2NFU(POS) converts 4-element position vector, POS from

% data space to normalized figure units, using the current axes. The

% position vector has the form [Xo Yo Width Height], as defined here:

%

% web(['jar:file:D:/Applications/MATLAB/R2006a/help/techdoc/' ...

% 'help.jar!/creating_plots/axes_pr4.html'], '-helpbrowser')

%

% [Xf, Yf] = DS2NFU(HAX, X, Y) converts X,Y coordinates from

% data space to normalized figure units, on specified axes HAX.

%

% POSf = DS2NFU(HAX, POS) converts 4-element position vector, POS from

% data space to normalized figure units, using the current axes.

%

% Ex.

% % Create some data

% t = 0:.1:4*pi;

% s = sin(t);

%

% % Add an annotation requiring (x,y) coordinate vectors

% plot(t,s);ylim([-1.2 1.2])

% xa = [1.6 2]*pi;

% ya = [0 0];

% [xaf,yaf] = ds2nfu(xa,ya);

% annotation('arrow',xaf,yaf)

%

% % Add an annotation requiring a position vector

% pose = [4*pi/2 .9 pi .2];

% posef = ds2nfu(pose);

% annotation('ellipse',posef)

%

% % Add annotations on a figure with multiple axes

% figure;

% hAx1 = subplot(211);

% plot(t,s);ylim([-1.2 1.2])

% hAx2 = subplot(212);

% plot(t,-s);ylim([-1.2 1.2])

% [xaf,yaf] = ds2nfu(hAx1,xa,ya);

% annotation('arrow',xaf,yaf)

% pose = [4*pi/2 -1.1 pi .2];

% posef = ds2nfu(hAx2,pose);

% annotation('ellipse',posef)

% Michelle Hirsch

% [e-mail]

% Copyright 2006-2014 The MathWorks, Inc

% updated for polar [e-mail]

%% Process inputs

error(nargchk(1, 3, nargin))

aspectRatio = 1.15;

XaspectRatio = 0.69;

% Determine if axes handle is specified

if length(varargin{1})== 1 && ishandle(varargin{1}) && strcmp(get(varargin{1},'type'),'axes')

hAx = varargin{1};

varargin = varargin(2:end);

else

hAx = gca;

end;

errmsg = ['Invalid input. Coordinates must be specified as 1 four-element \n' ...

'position vector or 2 equal length (x,y) vectors.'];

% Proceed with remaining inputs

if length(varargin)==1 % Must be 4 elt POS vector

pos = varargin{1};

if length(pos) ~=4,

error(errmsg);

end;

else

[th,r] = deal(varargin{:});

[x y] = pol2cart([th(1) th(2)],[r(1) r(2)]*aspectRatio);

x = x*XaspectRatio;

if length(x) ~= length(y)

error(errmsg)

end

end

%% Get limits

axun = get(hAx,'Units');

set(hAx,'Units','normalized');

axpos = get(hAx,'Position');

ax = axis(hAx);

axlim =[-ax(4) ax(4) -ax(4)*aspectRatio ax(4)*aspectRatio];

axwidth = diff(axlim(1:2));

axheight = diff(axlim(3:4));

%% Transform data

if exist('x','var')

varargout{1} = (x-axlim(1))*axpos(3)/axwidth + axpos(1);

varargout{2} = (y-axlim(3))*axpos(4)/axheight + axpos(2);

else

pos(1) = (pos(1)-axlim(1))/axwidth*axpos(3) + axpos(1);

pos(2) = (pos(2)-axlim(3))/axheight*axpos(4) + axpos(2);

pos(3) = pos(3)*axpos(3)/axwidth;

pos(4) = pos(4)*axpos(4)/axheight;

varargout{1} = pos;

end

%% Restore axes units

set(hAx,'Units',axun)