heatmap.m

function [hImage, hText, hXText] = heatmap(mat, xlab, ylab, textmat, varargin)
% HEATMAP displays a matrix as a heatmap image
%
% USAGE:
% [hImage, hText, hTick] = heatmap(matrix, xlabels, ylabels, textmatrix, 'param', value, ...)
%
% INPUTS:
% * HEATMAP displays "matrix" as an image whose color intensities reflect
%   the magnitude of the values in "matrix". 
%
% * "xlabels" (and "ylabels") can be either a numeric vector or cell array
%   of strings that represent the columns (or rows) of the matrix. If either
%   is not specified or empty, no labels will be drawn. 
%
% * "textmat" can either be: 1 (or true), in which case the "matrix" values will be
%   displayed in each square, a format string, in which case the matrix
%   values will be displayed formatted according to the string specified, a numeric
%   matrix the size of "matrix", in which case those values will be displayed as
%   strings or a cell matrix of strings the size of "matrix", in which case each
%   string will be displayed. If not specified or empty, no text will be
%   displayed on the image
%
% OTHER PARAMETERS (passed as parameter-value pairs)
% * 'Colormap': Either a matrix of size numLevels-by-3 representing the
%   colormap to be used or a string or function handle representing a
%   function that returns a colormap, example, 'jet', 'hsv' or @cool.
%   Non-standard colormaps available within HEATMAP include 'money' and 'red'.
%   By default, the current figure's colormap is used.
%
% * 'ColorLevels': The number of distinct levels in the colormap (default:
%   64). If more levels are specified than are present in the colormap, the
%   levels in the colormap are interpolated. If fewer are specified the
%   colormap is downsampled.
%
% * 'UseLogColormap': A true/false value which, if true, specifies that the
%   intensities displayed should match the log of the "matrix" values. Use
%   this if the data is naturally on a logarithmic scale (default: false)
%
% * 'UseFigureColormap': Specifies whether the figure's colormap should be
%   used. If false, the color intensities after applying the
%   specified/default colormap will be hardcoded, so that the image will be
%   independent of the figures colormap. If this option is true, the figure
%   colormap in the end will be replaced by specified/default colormap.
%   (default = true)
%
% * 'Parent': Handle to an axes object
%
% * 'TextColor': Either a color specification of all the text displayed on
%   the image or a string 'xor' which sets the EraseMode property of the text
%   objects to 'xor'. This will display all the text labels in a color that
%   contrasts its background.
%
% * 'FontSize': The initial fontSize of the text labels on the image. As
%   the image size is scaled the fontSize is shrunk appropriately.
%
% * 'ColorBar': Display colorbar. The corresponding value parameter should
%   be either logical 1 or 0 or a cell array of any additional parameters
%   you wish to pass to the colorbar function (such as location)
%
% * 'GridLines': Draw grid lines separating adjacent sections of the
%   heatmap. The value of the parameter is a LineStyle specification, for example,
%   :, -, -. or --. By default, no grid lines are drawn.
%
% * 'TickAngle': Angle of rotation of tick labels on x-axis. (Default: 0)
%
% * 'ShowAllTicks': Set to 1 or true to force all ticks and labels to be
%   drawn. This can make the axes labels look crowded. (Default: false)
%
% * 'TickFontSize': Font size of the X and Y tick labels. Default value is
%   the default axes font size, usually 10. Set to a lower value if many
%   tick labels are being displayed
%
% OUTPUTS:
% * hImage: handle to the image object
% * hText : handle to the text objects (empty if no text labels are drawn)
% * hTick : handle to the X-tick label text objects if tick angle is not 0
%           (empty otherwise)
%
% Notes:
% * The 'money' colormap displays a colormap where 0 values are mapped to
%   white, negative values displayed in varying shades of red and positive
%   values in varying shades of green
% * The 'red' colormap maps 0 values to white and higher values to red
%
% EXAMPLES:
% data = reshape(sort(randi(100,10)),10,10)-50;
% heatmap(data, cellstr(('A':'J')'), mean(data,2), '%0.0f%%',...
%         'Colormap', 'money', 'Colorbar', true, 'GridLines', ':',...
%         'TextColor', 'b')
% For detailed examples, see the associated document heatmap_examples.m

% Handle missing inputs
if nargin < 1, error('Heatmap requires at least one input argument'); end
if nargin < 2, xlab = []; end
if nargin < 3, ylab = []; end
if nargin < 4, textmat = []; end

% Parse parameter/value inputs
p = parseInputs(varargin{:});

% Calculate the colormap based on inputs
p = calculateColormap(p, mat);

% Create heatmap image
p = plotHeatmap(p, mat); % New properties hImage and cdata added

% Generate grid lines if selected
generateGridLines(p);

% Set axes labels
[p, xlab, ylab, hXText] = setAxesLabels(p, xlab, ylab);

% Set text labels
[p, displayText, fontScaleFactor] = setTextLabels(p, mat, textmat);

% Add colorbar if selected
addColorbar(p, mat, textmat)

% Store heatmap properties in axes for callbacks
axesInfo = struct('Type', 'heatmap', 'Parameters', p, 'FontScaleFactor', ...
                   fontScaleFactor, 'mat', mat, 'hXText', hXText);
axesInfo.xlab = xlab;
axesInfo.ylab = ylab;
axesInfo.displayText = displayText;

set(p.hAxes, 'UserData', axesInfo);

% Define callbacks
dObj = datacursormode(p.hFig);
set(dObj, 'Updatefcn', @cursorFun);

zObj = zoom(p.hFig);
set(zObj, 'ActionPostCallback', @(obj,evd)updateLabels(evd.Axes,true));

pObj = pan(p.hFig);
% set(pObj, 'ActionPreCallback',  @prePan);
set(pObj, 'ActionPostCallback', @(obj,evd)updateLabels(evd.Axes,true));

set(p.hFig, 'ResizeFcn', @resize)

% Set outputs
hImage = p.hImage;
hText = p.hText;

end

% ---------------------- Heatmap Creation Functions ----------------------

% Parse PV inputs & return structure of parameters
function param = parseInputs(varargin) 

p = inputParser;
p.addParamValue('Colormap',[]);
p.addParamValue('ColorLevels',[]);
p.addParamValue('TextColor',[0 0 0]);
p.addParamValue('UseFigureColormap',true);
p.addParamValue('UseLogColormap',false);
p.addParamValue('Parent',gca);
p.addParamValue('FontSize',[]);
p.addParamValue('Colorbar',[]);
p.addParamValue('GridLines','none');
p.addParamValue('TickAngle',0);
p.addParamValue('ShowAllTicks',false);
p.addParamValue('TickFontSize',[]);
p.parse(varargin{:});

param = p.Results;

% Add a few other parameters
param.hAxes = param.Parent;
param.hFig = get(param.hAxes, 'Parent');

end

% Visualize heatmap image
function p = plotHeatmap(p, mat)
p.cdata = [];
if p.UseLogColormap
    p.Colormap = resamplecmap(p.Colormap, p.ColorLevels, ...
                           logspace(0,log10(p.ColorLevels),p.ColorLevels));
end
if p.UseFigureColormap 
    % Use scaled image plot to let the figure's colormap automatically
    % convert from the matrix to color data
    set(p.hFig,'Colormap',p.Colormap);
    cla(p.hAxes);
    p.hImage = imagesc(mat, 'Parent', p.hAxes);
else
    % Calculate the color data explicitly and then display it as an image.
    n = min(mat(:));
    x = max(mat(:));
    if x == n, x = n+1; end
    p.cdata = round((mat-n)/(x-n)*(p.ColorLevels-1)+1);
    %p.cdata = ceil((mat-n)/(x-n)*p.ColorLevels);
    p.cdata = reshape(p.Colormap(p.cdata(:),:),[size(p.cdata) 3]);
    p.hImage = image(p.cdata, 'Parent', p.hAxes);
end
end

% Generate grid lines
function generateGridLines(p)
if ~strcmp(p.GridLines,'none')
    xlim = get(p.hAxes,'XLim');
    ylim = get(p.hAxes,'YLim');
    for i = 1:diff(xlim)-1
        line('Parent',p.hAxes,'XData',[i i]+.5, 'YData', ylim, 'LineStyle', p.GridLines);
    end
    for i = 1:diff(ylim)-1
        line('Parent',p.hAxes,'XData',xlim, 'YData', [i i]+.5, 'LineStyle', p.GridLines);
    end
end
end

% Add color bar
function addColorbar(p, mat, textmat)

if isempty(p.Colorbar)
    return;
elseif iscell(p.Colorbar)
    c = colorbar(p.Colorbar{:});
else
    c = colorbar;
end
ticks = get(c,'YTick');
if isempty(ticks)
    ticks = get(c,'XTick');
    tickAxis = 'X';
else
    tickAxis = 'Y';
end
    
if ~p.UseFigureColormap
    d = findobj(get(c,'Children'),'Tag','TMW_COLORBAR'); % Image
    %cdata = get(d,'Cdata');
    %ytick = get(d,'YTick');
    %ytl = get(g,'YTickLabel');
    set(d,'CData',reshape(p.Colormap,[p.ColorLevels 1 3]))
    set(c,'YLim',[1 p.ColorLevels]);
    n = min(mat(:));
    x = max(mat(:));
    if x == n, x = n+1; end
    ticks = (ticks-1)*(x-n)/(p.ColorLevels-1)+n;
end
if ~isempty(ticks)
    
    if ischar(textmat) % If format string, format colorbar ticks in the same way
        ticklabels = arrayfun(@(x){sprintf(textmat,x)},ticks);
    else
        ticklabels = num2str(ticks(:));
    end
    set(c, [tickAxis 'TickLabel'], ticklabels);
end


end


% ------------------------- Tick Label Functions -------------------------

% Set axes labels
function [p, xlab, ylab, hXText] = setAxesLabels(p, xlab, ylab)

if isempty(p.TickFontSize)
    p.TickFontSize = get(p.hAxes, 'FontSize');
else
    set(p.hAxes, 'FontSize', p.TickFontSize);
end

if isempty(ylab) % No ticks or labels
    set(p.hAxes,'YTick',[],'YTickLabel','');
else
    if isnumeric(ylab) % Numeric tick labels
        ylab = arrayfun(@(x){num2str(x)},ylab);
    end
    if p.ShowAllTicks
        ytick = 1:length(ylab);
    else
        ytick = get(p.hAxes, 'YTick');
    end
    set(p.hAxes,'YTick',ytick,'YTickLabel',ylab(ytick));
end
% Xlabels are trickier because they could have a TickAngle
hXText = []; % Default value
if isempty(xlab)
    set(p.hAxes,'XTick',[],'XTickLabel','');
else
    if isnumeric(xlab)
        xlab = arrayfun(@(x){num2str(x)},xlab);
    end
    if p.ShowAllTicks
        xtick = 1:length(xlab);
    else
        xtick = get(p.hAxes, 'XTick');
    end
    if p.TickAngle == 0
        set(p.hAxes,'XTick',xtick,'XTickLabel',xlab(xtick));
    else
        hXText = createXTicks(p.hAxes, p.TickAngle, xtick, xlab(xtick));
        adjustAxesToAccommodateTickLabels(p.hAxes, hXText);
    end
end



end

% Create Rotated X Tick Labels
function hXText = createXTicks(hAxes, tickAngle, xticks, xticklabels)

    axXLim = get(hAxes, 'XLim');
    [xPos, yPos] = calculateTextTickPositions(hAxes, axXLim, xticks);
            
    hXText = text(xPos, yPos, cellstr(xticklabels), 'Units', 'normalized', ...
                  'Parent', hAxes, 'FontSize', get(hAxes,'FontSize'), ...
                  'HorizontalAlignment', 'right', 'Rotation', tickAngle,...
                  'Interpreter', 'none');
                
    set(hAxes, 'XTick', xticks, 'XTickLabel', '');

end

% Calculate positions of X tick text objects in normalized units
function [xPos, yPos] = calculateTextTickPositions(hAxes, xlim, ticks)
oldunits = get(hAxes,'Units');
set(hAxes,'units','pixels');
axPos = get(hAxes,'position');
set(hAxes,'units',oldunits);

xPos = (ticks - xlim(1))/diff(xlim);
%yPos = -.08 * ones(size(xPos));
yPos = -7.82/axPos(4) * ones(size(xPos));
end

% Adjust axes and tick positions so that everything fits well on screen
function adjustAxesToAccommodateTickLabels(hAxes, hXText)
% The challenge here is that the axes container, especially in a subplot is
% not well defined. The outer position property does not fully span or
% contain the x tick text objects. So here we just shrink the axes height
% just a little so that the axes and tick labels take the same room as the
% axes would have without the ticks.

[axPosP, axPosN, axOPP, axOPN, coPosP, textPosP]  = ...
    getGraphicsObjectsPositions(hAxes, hXText); %#ok<ASGLU>

header = axOPP(4) + axOPP(2) - axPosP(4) - axPosP(2); % Distance between top of axes and container in pixels; 
delta = 5; % To adjust for overlap between area designated for regular ticks and area occupied by rotated ticks
axHeightP = axOPP(4) - header - delta - textPosP(4);

% Fudge axis position if labels are taking up too much room
if textPosP(4)/(textPosP(4)+axHeightP) > .7 % It's taking up more than 70% of total height
    axHeightP = (1/.7-1) * textPosP(4); % Minimum axis 
end
axHeightN = max(0.0001, axHeightP / coPosP(4));

axPosN = axPosN + [0 axPosN(4)-axHeightN 0 axHeightN-axPosN(4)];
set(hAxes,'Position', axPosN)

end

% Calculate graphics objects positions in pixels and normalized units
function [axPosP, axPosN, axOPP, axOPN, coPosP, textPosP, textPosN] =...
         getGraphicsObjectsPositions(hAxes, hXText)

axPosN = get(hAxes, 'Position'); axOPN = get(hAxes, 'OuterPosition');
set(hAxes,'Units','Pixels');
axPosP = get(hAxes, 'Position'); axOPP = get(hAxes, 'OuterPosition');
set(hAxes,'Units','Normalized');

hContainer = get(hAxes,'Parent');
units = get(hContainer,'Units');
set(hContainer,'Units','Pixels');
coPosP = get(hContainer,'Position');
set(hContainer,'Units',units);

set(hXText,'Units','pixels'); % Measure height in pixels
extents = get(hXText,'Extent'); % Get heights for all text objects
extents = vertcat(extents{:}); % Collect heights in one matrix
textPosP = [min(extents(:,1)) min(extents(:,2)) ...
    max(extents(:,3)+extents(:,1))-min(extents(:,1)) ...
    max(extents(:,4))]; % Find dimensions of text label block
set(hXText,'Units','normalized'); % Restore previous behavior
extents = get(hXText,'Extent'); % Get heights for all text objects
extents = vertcat(extents{:}); % Collect heights in one matrix
textPosN = [min(extents(:,1)) min(extents(:,2)) ...
    max(extents(:,3)+extents(:,1))-min(extents(:,1)) ...
    max(extents(:,4))]; % Find dimensions of text label block

end


% -------------------------- Callback Functions --------------------------

% Update x-, y- and text-labels with respect to axes limits
function updateLabels(hAxes, axesLimitsChanged)

axInfo = getHeatmapAxesInfo(hAxes);
if isempty(axInfo), return; end
p = axInfo.Parameters;

% Update text font size to fill the square
if ~isempty(p.hText) && ishandle(p.hText(1))
    fs = axInfo.FontScaleFactor * getBestFontSize(hAxes);
    if fs > 0
        set(p.hText,'fontsize',fs,'visible','on');
    else
        set(p.hText,'visible','off');
    end
end

if axesLimitsChanged && ~isempty(axInfo.displayText) % If limits change & text labels are displayed
    % Get positions of text objects
    textPos = get(p.hText,'Position');
    textPos = vertcat(textPos{:});
    % Get axes limits
    axXLim = get(hAxes, 'XLim');
    axYLim = get(hAxes, 'YLim');
    % Find text objects within axes limit
    ind = textPos(:,1) > axXLim(1) & textPos(:,1) < axXLim(2) & ...
        textPos(:,2) > axYLim(1) & textPos(:,2) < axYLim(2);
    set(p.hText(ind), 'Visible', 'on');
    set(p.hText(~ind), 'Visible', 'off');
end
    
% Modify Y Tick Labels

if ~isempty(axInfo.ylab)
    axYLim = get(hAxes, 'YLim');
    if p.ShowAllTicks
        yticks = ceil(axYLim(1)):floor(axYLim(2));
    else
        set(hAxes, 'YTickMode', 'auto');
        yticks = get(hAxes, 'YTick');
        yticks = yticks( yticks == floor(yticks) );
    end
    ylabels = repmat({''},1,max(yticks));
    ylabels(1:length(axInfo.ylab)) = axInfo.ylab;
    set(hAxes, 'YTick', yticks, 'YTickLabel', ylabels(yticks));
end
    
if ~isempty(axInfo.xlab)    
    
    axXLim = get(hAxes, 'XLim');

    if p.ShowAllTicks
        xticks = ceil(axXLim(1)):floor(axXLim(2));
    else
        set(hAxes, 'XTickMode', 'auto');
        xticks = get(hAxes, 'XTick');
        xticks = xticks( xticks == floor(xticks) );
    end
    xlabels = repmat({''},1,max(xticks));
    xlabels(1:length(axInfo.xlab)) = axInfo.xlab;
    
    if ~isempty(axInfo.hXText) % Rotated X tick labels exist
        try delete(axInfo.hXText); end %#ok<TRYNC>
        axInfo.hXText = createXTicks(hAxes, p.TickAngle, xticks, xlabels(xticks));
        set(hAxes, 'UserData', axInfo);
    else
        set(hAxes, 'XTick', xticks, 'XTickLabel', xlabels(xticks));
    end
    
    %adjustAxesToAccommodateTickLabels(hAxes, axInfo.hXText)
end

end

% Callback for data cursor
function output_txt = cursorFun(obj, eventdata)
hAxes = ancestor(eventdata.Target, 'axes');
axInfo = getHeatmapAxesInfo(hAxes);

pos = eventdata.Position;

if ~isempty(axInfo)
    
    try
        val = axInfo.displayText{pos(2), pos(1)};
    catch %#ok<CTCH>
        val = num2str(axInfo.mat(pos(2), pos(1)));
    end
    if isempty(axInfo.xlab), i = int2str(pos(1)); else i = axInfo.xlab{pos(1)}; end
    if isempty(axInfo.ylab), j = int2str(pos(2)); else j = axInfo.ylab{pos(2)}; end
    output_txt = sprintf('X: %s\nY: %s\nVal: %s', i, j, val);
    
else
    if length(pos) == 2
        output_txt = sprintf('X: %0.4g\nY: %0.4g', pos(1), pos(2));
    else
        output_txt = sprintf('X: %0.4g\nY: %0.4g\nZ: %0.4g', pos(1), pos(2), pos(3));
    end
end
end

% Callback for resize event
function resize(obj, evd)
hAxes = findobj(obj, 'type', 'axes');
for i = 1:length(hAxes)
    updateLabels(hAxes(i), false); 
end
end

% Extract heatmap parameters for callback
function axInfo = getHeatmapAxesInfo(axH)
axInfo = get(axH, 'UserData');
try
    if ~strcmp(axInfo.Type, 'heatmap')
        axInfo = [];
    end
catch %#ok<CTCH>
    axInfo = [];
end
end


% ------------------------- Text Label Functions -------------------------

% Create text labels
function [p, displaytext, factor] = setTextLabels(p, mat, textmat)

if isempty(textmat)
    p.hText = [];
    displaytext = {};
    factor = 0;
    return
end
    
if isscalar(textmat) && textmat % If true convert mat to text
    displaytext = arrayfun(@(x){num2str(x)},mat);
elseif ischar(textmat) % If a format string, convert mat to text with specific format
    displaytext = arrayfun(@(x){sprintf(textmat,x)},mat);
elseif isnumeric(textmat) && numel(textmat)==numel(mat) % If numeric, convert to text
    displaytext = arrayfun(@(x){num2str(x)},textmat);
elseif iscellstr(textmat) && numel(textmat)==numel(mat) % If cell array of strings, it is already formatted
    displaytext = textmat;
else
    error('texmat is incorrectly specified');
end

if ischar(p.TextColor) && strcmp(p.TextColor,'xor')
    colorprop = 'EraseMode';
else
    colorprop = 'Color';
end

autoFontSize = getBestFontSize(p.hAxes);
if isempty(p.FontSize)
    p.FontSize = autoFontSize;
end
[xpos,ypos] = meshgrid(1:size(mat,2),1:size(mat,1));
if p.FontSize > 0
    p.hText = text(xpos(:),ypos(:),displaytext(:),'FontSize',p.FontSize,...
        'HorizontalAlignment','center', colorprop, p.TextColor);
else
    p.hText = text(xpos(:),ypos(:),displaytext(:),'Visible','off',...
        'HorizontalAlignment','center', colorprop, p.TextColor);
end

% Calculate factor to scale font size in future callbacks
factor = p.FontSize/autoFontSize;
if isnan(factor), factor = 1; end
if isinf(factor), factor = p.FontSize/6; end

% % Set up listeners to handle appropriate zooming
% addlistener(p.hAxes,{'XLim','YLim'},'PostSet',@(obj,evdata)resizeText);
% try
%     addlistener(p.hFig,'SizeChange',@(obj,evdata)resizeText);
% catch
%     addlistener(p.hFig,'Resize',@(obj,evdata)resizeText);
% end



%     function resizeText
%         if ~isempty(hText) && ishandle(hText(1))
%             fs = factor*getBestFontSize(hAxes);
%             if fs > 0
%                 set(hText,'fontsize',fs,'visible','on');
%             else
%                 set(hText,'visible','off');
%             end
%         end
%     end

end

% Guess best font size from axes size using heuristics
function fs = getBestFontSize(imAxes)

hFig = ancestor(imAxes,'figure');
magicNumber = 80;
nrows = diff(get(imAxes,'YLim'));
ncols = diff(get(imAxes,'XLim'));
if ncols < magicNumber && nrows < magicNumber
    ratio = max(get(hFig,'Position').*[0 0 0 1])/max(nrows,ncols);
elseif ncols < magicNumber
    ratio = max(get(hFig,'Position').*[0 0 0 1])/ncols;
elseif nrows < magicNumber
    ratio = max(get(hFig,'Position').*[0 0 0 1])/nrows;
else
    ratio = 1;
end
fs = min(9,ceil(ratio/4));    % the gold formula
if fs < 4
    fs = 0;
end
end

% -------------------------- Colormap Functions --------------------------

% Determine the colormap to use
function p = calculateColormap(p, mat)

if isempty(p.Colormap)
    p.Colormap = get(p.hFig,'Colormap');
    if isempty(p.ColorLevels)
        p.ColorLevels = size(p.Colormap,1);
    else
        p.Colormap = resamplecmap(p.Colormap, p.ColorLevels);
    end
elseif ischar(p.Colormap) || isa(p.Colormap,'function_handle')
    if isempty(p.ColorLevels), p.ColorLevels = 64; end
    if strcmp(p.Colormap, 'money')
        p.Colormap = money(mat, p.ColorLevels);
    else
        p.Colormap = feval(p.Colormap,p.ColorLevels);
    end
elseif iscell(p.Colormap)
    p.Colormap = feval(p.Colormap{1}, p.Colormap{2:end});
    p.ColorLevels = size(p.Colormap,1);
elseif isnumeric(p.Colormap) && size(p.Colormap,2) == 3
    p.ColorLevels = size(p.Colormap,1);
else
    error('Incorrect value for colormap parameter');
end % p.Colormap is now a p.ColorLevels-by-3 rgb vector
assert(p.ColorLevels == size(p.Colormap,1));

end

% Resample a colormap by interpolation or decimation
function cmap = resamplecmap(cmap, clevels, xi)

t = cmap;
if nargin < 3
    xi = linspace(1,clevels,size(t,1)); 
end
xi([1 end]) = [1 clevels]; % These need to be exact for the interpolation to 
% work and we don't want machine precision messing it up
cmap = [interp1(xi, t(:,1), 1:clevels);...
        interp1(xi, t(:,2), 1:clevels);...
        interp1(xi, t(:,3), 1:clevels)]';
end

% Generate Red-White-Green color map
function cmap = money(data, clevels)
% Function to make the heatmap have the green, white and red effect
n = min(data(:));
x = max(data(:));
if x == n, x = n+1; end
zeroInd = round(-n/(x-n)*(clevels-1)+1);
if zeroInd <= 1 % Just green
    b = interp1([1 clevels], [1 0], 1:clevels);
    g = interp1([1 clevels], [1 1], 1:clevels);
    r = interp1([1 clevels], [1 0], 1:clevels);
elseif zeroInd >= clevels, % Just red
    b = interp1([1 clevels], [0 1], 1:clevels);
    g = interp1([1 clevels], [0 1], 1:clevels);
    r = interp1([1 clevels], [1 1], 1:clevels);
else
    b = interp1([1 zeroInd clevels], [0 1 0], 1:clevels); 
    g = interp1([1 zeroInd clevels], [0 1 1], 1:clevels);
    r = interp1([1 zeroInd clevels], [1 1 0], 1:clevels);
end

cmap = [r' g' b'];
end

% Generate Red-White color map
function cmap = red(levels)
r = ones(levels, 1);
g = linspace(1, 0, levels)'; 
cmap = [r g g];
end






%#ok<*INUSD>
%#ok<*DEFNU>
%#ok<*INUSL>