function h = surf(varargin)

%SURF   3-D colored surface.

%   SURF(X,Y,Z,C) plots the colored parametric surface defined by

%   four matrix arguments.  The view point is specified by VIEW.

%   The axis labels are determined by the range of X, Y and Z,

%   or by the current setting of AXIS.  The color scaling is determined

%   by the range of C, or by the current setting of CAXIS.  The scaled

%   color values are used as indices into the current COLORMAP.

%   The shading model is set by SHADING.

%

%   SURF(X,Y,Z) uses C = Z, so color is proportional to surface height.

%

%   SURF(x,y,Z) and SURF(x,y,Z,C), with two vector arguments replacing

%   the first two matrix arguments, must have length(x) = n and

%   length(y) = m where [m,n] = size(Z).  In this case, the vertices

%   of the surface patches are the triples (x(j), y(i), Z(i,j)).

%   Note that x corresponds to the columns of Z and y corresponds to

%   the rows.

%

%   SURF(Z) and SURF(Z,C) use x = 1:n and y = 1:m.  In this case,

%   the height, Z, is a single-valued function, defined over a

%   geometrically rectangular grid.

%

%   SURF(...,'PropertyName',PropertyValue,...) sets the value of the

%   specified surface property.  Multiple property values can be set

%   with a single statement.

%

%   SURF(AX,...) plots into AX instead of GCA.

%

%   SURF returns a handle to a surface plot object.

%

%   AXIS, CAXIS, COLORMAP, HOLD, SHADING and VIEW set figure, axes, and

%   surface properties which affect the display of the surface.

%

%   See also SURFC, SURFL, MESH, SHADING.

%-------------------------------

%   Additional details:

%

%   If the NextPlot axis property is REPLACE (HOLD is off), SURF resets

%   all axis properties, except Position, to their default values

%   and deletes all axis children (line, patch, surf, image, and

%   text objects).

%   Copyright 1984-2017 The MathWorks, Inc.

%   J.N. Little 1-5-92

narginchk(1,inf) 

[~, cax, args] = parseplotapi(varargin{:},'-mfilename',mfilename); 

nargs = length(args); 

args = matlab.graphics.internal.convertStringToCharArgs(args); 

hadParentAsPVPair = false; 

if nargs > 1 

    % try to fetch axes handle from input args,

    % and allow it to override the possible input "cax"

    for i = 1:length(args) 

        isValid = ~isempty(args{i}) && matlab.graphics.internal.isCharOrString(args{i}); 

        hasParentArg = strncmpi(args{i}, 'parent', length(args{i})); 

        if isValid && hasParentArg && nargs > i 

            cax = args{i+1};

            hadParentAsPVPair = true;

            break;

        end 

    end 

end 

% do input checking

dataargs = parseparams(args); 

error(surfchk(dataargs{:})); 

% use nextplot unless user specified an axes handle in pv pairs

% required for backwards compatibility

if isempty(cax) || ~hadParentAsPVPair 

    if ~isempty(cax) && ~ishghandle(cax,'Axes') 

        parax = cax;

        cax = ancestor(cax,'Axes');

        nextPlot = 'add';

    else 

        showInteractionInfoPanel = isempty(get(groot,'CurrentFigure')); 

        res = matlab.ui.internal.webGraphicsStateManager; 

        cax = newplot(cax); 

        parax = cax; 

        nextPlot = cax.NextPlot; 

        if showInteractionInfoPanel 

            % Maybe open the Interaction Info Panel

            matlab.graphics.internal.InteractionInfoPanel.maybeShow(cax);

        end 

    end 

else

    cax = newplot(cax);

    parax = cax;

    nextPlot = cax.NextPlot;

end 

% We need to separate out convenience arguments from P/V pairs:

% First, determine the number of numeric data arguments:

len = length(args); 

n = 1; 

while n<=len && isplottable(args{n}) 

    n = n+1; 

end 

n = n-1; 

% Determine the appropriate syntax:

params = {}; 

switch(n) 

    case 1 

        % SURF(Z,...)

        z = args{1};

        matlab.graphics.internal.configureAxes(cax,[],[],z);

        [~,~,z] = matlab.graphics.internal.makeNumeric(cax,[],[],z);

        params = {'ZData',z};

        args = args(2:end);

    case 2 

        % SURF(Z,C,...)

        z = args{1};

        matlab.graphics.internal.configureAxes(cax,[],[],z);

        [~,~,z] = matlab.graphics.internal.makeNumeric(cax,[],[],z);

        params = {'ZData',z,'CData',args{2}};

        args = args(3:end);

    case 3 

        % SURF(X,Y,Z,...)

        x = args{1}; 

        y = args{2}; 

        z = args{3}; 

        matlab.graphics.internal.configureAxes(cax,x,y,z); 

        [x,y,z] = matlab.graphics.internal.makeNumeric(cax,x,y,z); 

        params = {'XData',x,'YData',y,'ZData',z}; 

        args = args(4:end); 

    case 4

        % SURF(X,Y,Z,C,...)

        x = args{1};

        y = args{2};

        z = args{3};

        matlab.graphics.internal.configureAxes(cax,x,y,z);

        [x,y,z] = matlab.graphics.internal.makeNumeric(cax,x,y,z);

        params = {'XData',x,'YData',y,'ZData',z,'CData',args{4}};

        args = args(5:end);

end 

%Place parenting arguments first so that parent-sensitive properties 

%eg. UIContextMenu are set after surface is parented.

allargs = [params, {'Parent',parax}, args];  

hh = matlab.graphics.chart.primitive.Surface(allargs{:}); 

switch nextPlot 

    case {'replaceall','replace'} 

        view(cax,3); 

        grid(cax,'on'); 

    case {'replacechildren'}

        view(cax,3);

end 

if nargout == 1 

    h = hh;

end