Code covered by the BSD License

# Polar 2

### Daniel Armyr (view profile)

08 Apr 2009 (Updated )

An update to Matlabs built-in polar.m

polar2(varargin)
```function hpol = polar2(varargin)
%POLAR  Polar coordinate plot.
%   POLAR(THETA, RHO) makes a plot using polar coordinates of
%   POLAR(THETA,RHO,R) uses the radial limits specified by the two element
%   vector R. If R is a 4-element vector, the second two elements are
%   angular limits.
%   POLAR(THETA,RHO,S) uses the linestyle specified in string S.
%   See PLOT for a description of legal linestyles.
%   POLAR(THETA,RHO,R,S) uses the linestyle specified in string S and the
%
%   POLAR(AX,...) plots into AX instead of GCA.
%
%   H = POLAR(...) returns a handle to the plotted object in H.
%
%   Example:
%      t = 0:.01:2*pi;
%      polar(t,sin(2*t).*cos(2*t),'--r')
%
%
%   Revised version by Daniel Armyr, 2009. Based on Mathworks original.

%   Copyright 1984-2007 The MathWorks, Inc.
%   \$Revision: 5.22.4.9 \$  \$Date: 2007/08/27 17:06:52 \$

% Parse possible Axes input
[cax,args,nargs] = axescheck(varargin{:});
error(nargchk(1,4,nargs,'struct'));

if nargs < 1 || nargs > 4
error('MATLAB:polar:InvalidInput', 'Requires 2 to 4 data arguments.')
elseif nargs == 2
theta = args{1};
rho = args{2};
if ischar(rho)
line_style = rho;
rho = theta;
[mr,nr] = size(rho);
if mr == 1
theta = 1:nr;
else
th = (1:mr)';
theta = th(:,ones(1,nr));
end
else
line_style = 'auto';
end
elseif nargs == 1
theta = args{1};
line_style = 'auto';
rho = theta;
[mr,nr] = size(rho);
if mr == 1
theta = 1:nr;
else
th = (1:mr)';
theta = th(:,ones(1,nr));
end
elseif nargs == 3
if ( ischar(args{3}) )
[theta,rho,line_style] = deal(args{1:3});
else
line_style = 'auto';
if ( numel(radial_limits) == 2 )
elseif ( ~(numel(radial_limits) == 4) )
error ( 'R must be a 2 element vector' );
end
end
else %nargs == 4
if ( numel(radial_limits) == 2 )
elseif ( ~(numel(radial_limits) == 4) )
error ( 'R must be a 2 element vector' );
end
end

if ischar(theta) || ischar(rho)
error('MATLAB:polar:InvalidInputType', 'Input arguments must be numeric.');
end
if ~isequal(size(theta),size(rho))
error('MATLAB:polar:InvalidInput', 'THETA and RHO must be the same size.');
end

% get hold state
cax = newplot(cax);

next = lower(get(cax,'NextPlot'));
hold_state = ishold(cax);

% get x-axis text color so grid is in same color
tc = get(cax,'xcolor');
ls = get(cax,'gridlinestyle');

% Hold on to current Text defaults, reset them to the
% Axes' font attributes so tick marks use them.
fAngle  = get(cax, 'DefaultTextFontAngle');
fName   = get(cax, 'DefaultTextFontName');
fSize   = get(cax, 'DefaultTextFontSize');
fWeight = get(cax, 'DefaultTextFontWeight');
fUnits  = get(cax, 'DefaultTextUnits');
set(cax, 'DefaultTextFontAngle',  get(cax, 'FontAngle'), ...
'DefaultTextFontName',   get(cax, 'FontName'), ...
'DefaultTextFontSize',   get(cax, 'FontSize'), ...
'DefaultTextFontWeight', get(cax, 'FontWeight'), ...
'DefaultTextUnits','data')

% only do grids if hold is off
if ~hold_state

hold(cax,'on');
set(cax,'dataaspectratio',[1 1 1],'plotboxaspectratiomode','auto')

% ensure that Inf values don't enter into the limit calculation.
arho = abs(rho(:));
maxrho = max(arho(arho ~= Inf));
minrho = 0;
hhh=line([minrho minrho maxrho maxrho],[minrho maxrho maxrho minrho],'parent',cax);
v = [get(cax,'xlim') get(cax,'ylim')];
ticks = numel(get(cax,'ytick'));
delete(hhh);
% check radial limits and ticks
rmin = v(1); rmax = v(4); rticks = max(ticks-1,2);
if rticks > 5   % see if we can reduce the number
if rem(rticks,2) == 0
rticks = rticks/2;
elseif rem(rticks,3) == 0
rticks = rticks/3;
end
end
rinc = (rmax-rmin)/rticks;

else

order = (10^floor(log10(rmax-rmin)));
firstDigit = floor((rmax-rmin)/order);
if ( firstDigit <= 1 )
step = 0.2*order;
elseif ( firstDigit <= 3 )
step = 0.5*order;
elseif ( firstDigit <= 7 )
step = order;
else
step = 2*order;
end
rinc = step;

%Also, make sure to drop any values outside the limits.
if ( rmin == 0 )
subset = rho >= -rmax & rho <= rmax & theta >= thmin & theta <= thmax;
else
subset = rho >= rmin & rho <= rmax & theta >= thmin & theta <= thmax;
end
theta(~subset) = nan;
rho(~subset) = nan;
end

% define a circle
th = 0:pi/50:2*pi;
xunit = cos(th);
yunit = sin(th);
% now really force points on x/y axes to lie on them exactly
inds = 1:(length(th)-1)/4:length(th);
xunit(inds(2:2:4)) = zeros(2,1);
yunit(inds(1:2:5)) = zeros(3,1);
% plot background if necessary
if ~ischar(get(cax,'color')),
patch('xdata',xunit*(rmax-rmin),'ydata',yunit*(rmax-rmin), ...
'edgecolor',tc,'facecolor',get(cax,'color'),...
'handlevisibility','off','parent',cax);
end

c82 = cos(82*pi/180);
s82 = sin(82*pi/180);
for i=(rmin+rinc):rinc:rmax
hhh = line(xunit*(i-rmin),yunit*(i-rmin),'linestyle',ls,'color',tc,'linewidth',1,...
'handlevisibility','off','parent',cax);
text((i-rmin+rinc/20)*c82,(i-rmin+rinc/20)*s82, ...
['  ' num2str(i)],'verticalalignment','bottom',...
'handlevisibility','off','parent',cax)
end
set(hhh,'linestyle','-') % Make outer circle solid

% plot spokes
th = (1:6)*2*pi/12;
cst = cos(th); snt = sin(th);
cs = [-cst; cst];
sn = [-snt; snt];
line((rmax-rmin)*cs,(rmax-rmin)*sn,'linestyle',ls,'color',tc,'linewidth',1,...
'handlevisibility','off','parent',cax)

% annotate spokes in degrees
rt = 1.1*(rmax-rmin);
for i = 1:length(th)
text(rt*cst(i),rt*snt(i),int2str(i*30),...
'horizontalalignment','center',...
'handlevisibility','off','parent',cax);
if i == length(th)
loc = int2str(0);
else
loc = int2str(180+i*30);
end
text(-rt*cst(i),-rt*snt(i),loc,'horizontalalignment','center',...
'handlevisibility','off','parent',cax)
end

% set view to 2-D
view(cax,2);
% set axis limits
axis(cax,(rmax-rmin)*[-1 1 -1.15 1.15]);

setappdata( cax, 'rMin', rmin );

else
%Try to find the inner radius of the current axis.
if ( isappdata ( cax, 'rMin' ) )
rmin = getappdata( cax, 'rMin' );
else
rmin = 0;
end
end

% Reset defaults.
set(cax, 'DefaultTextFontAngle', fAngle , ...
'DefaultTextFontName',   fName , ...
'DefaultTextFontSize',   fSize, ...
'DefaultTextFontWeight', fWeight, ...
'DefaultTextUnits',fUnits );

% transform data to Cartesian coordinates.
xx = (rho - rmin).*cos(theta);
yy = (rho - rmin).*sin(theta);

% plot data on top of grid
if strcmp(line_style,'auto')
q = plot(xx,yy,'parent',cax);
else
q = plot(xx,yy,line_style,'parent',cax);
end

if nargout == 1
hpol = q;
end

if ~hold_state
set(cax,'dataaspectratio',[1 1 1]), axis(cax,'off'); set(cax,'NextPlot',next);
end
set(get(cax,'xlabel'),'visible','on')
set(get(cax,'ylabel'),'visible','on')

if ~isempty(q) && ~isdeployed
makemcode('RegisterHandle',cax,'IgnoreHandle',q,'FunctionName','polar');
end
```