peaksCon(x)

function [c,ceq] = peaksCon(x)
%PEAKSCON Constraint function for optimization with PEAKSOBJ
%   PEAKSCON(X) is the constraint function for use with PEAKSOBJ.  X is of
%   size M x 2 or 2 x N.
%
%   Sytnax
%      [c,ceq] = peaksCon(x)
%
%   See also peaksobj, peaks

% Check x size to pass data correctly to constraint definition
[m,n] = size(x);
if (m*n) < 2
    error('peaksObj:inputMissing','Not enough inputs');
elseif (m*n) > 2 && (min(m,n) == 1) || (min(m,n) > 2)
    error('peaksObj:inputError','Input must have dimension m x 2');
elseif n ~= 2
    x = x';
end
% Set plot function to plot constraint boundary
try
    mypref = 'peaksNonlinearPlot';
    if ~ispref(mypref)
        addpref(mypref,'doplot',true);
    else
        setpref(mypref,'doplot',true);
    end
catch
end

% Define nonlinear equality constraint
ceq = [];

% Define nonlinear inequality constraint
% x1^2 + x^2 <= 3^2
c = x(:,1).^2 + x(:,2).^2 - 9; 
% fmincon accepted input form is ceq <= 0