eeg_colormap - generates EEG/ERP colormaps for eeg_toolbox
[p] = eeg_colormap(p)
Returns a colormap matrix [LENGTH, 3] into p.colorMap.map,
which can be used with matlab colormap command. For example:
[p] = eeg_colormap; colormap(p.colorMap.map);
The p.colorMap field is a struct with the following fields:
style: 'Gray' grayscale (always linear)
'Red/Blue' red/blue {default}
'Red/Blue/White' red/blue with white middle of width = WWIDTH
exp: Exponent {1=linear, 2=squared [default],3=cubed,etc.}.
Higher exponents increase contrast between the extreme
values and the middle values.
length: size of colormap matrix {25 default}.
If not even, it will be rounded down to nearest even number
Cmin: min RGB range, 0 <= RGB <=1; Cmin < Cmax {0 default}
Cmax: max RGB range, 0 <= RGB <=1; Cmax > Cmin {1 default}
plot: plot colormap, 1=plot, 0=no plot {0 default}0001 function [p] = eeg_colormap(p) 0002 0003 % eeg_colormap - generates EEG/ERP colormaps for eeg_toolbox 0004 % 0005 % [p] = eeg_colormap(p) 0006 % 0007 % Returns a colormap matrix [LENGTH, 3] into p.colorMap.map, 0008 % which can be used with matlab colormap command. For example: 0009 % 0010 % [p] = eeg_colormap; colormap(p.colorMap.map); 0011 % 0012 % The p.colorMap field is a struct with the following fields: 0013 % 0014 % style: 'Gray' grayscale (always linear) 0015 % 'Red/Blue' red/blue {default} 0016 % 'Red/Blue/White' red/blue with white middle of width = WWIDTH 0017 % exp: Exponent {1=linear, 2=squared [default],3=cubed,etc.}. 0018 % Higher exponents increase contrast between the extreme 0019 % values and the middle values. 0020 % length: size of colormap matrix {25 default}. 0021 % If not even, it will be rounded down to nearest even number 0022 % Cmin: min RGB range, 0 <= RGB <=1; Cmin < Cmax {0 default} 0023 % Cmax: max RGB range, 0 <= RGB <=1; Cmax > Cmin {1 default} 0024 % plot: plot colormap, 1=plot, 0=no plot {0 default} 0025 % 0026 0027 % $Revision: 1.1 $ $Date: 2004/11/12 01:32:33 $ 0028 0029 % Licence: GNU GPL, no implied or express warranties 0030 % History: 08/2001, Darren.Weber_at_radiology.ucsf.edu, created 0031 % 05/2001, Darren.Weber_at_radiology.ucsf.edu 0032 % - added EXP argument and changed default from 0033 % linear (EXP=1) to square (EXP=2). 0034 % - ensured that Length is an even number 0035 % - converted input/output to p struct 0036 % 0037 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0038 0039 if ~exist('p','var'), 0040 error('EEG_COLORMAP: No input p struct, use eeg_toolbox_defaults.'); 0041 else 0042 if ~isfield(p,'colorMap'), p.colorMap = []; end 0043 if ~isfield(p.colorMap,'style'), p.colorMap.style = 'Red/Blue/White'; end 0044 if ~isfield(p.colorMap,'exp'), p.colorMap.exp = 1; end 0045 if ~isfield(p.colorMap,'Cmin'), p.colorMap.Cmin = 0; end 0046 if ~isfield(p.colorMap,'Cmax'), p.colorMap.Cmax = 1; end 0047 if ~isfield(p.colorMap,'plot'), p.colorMap.plot = 0; end 0048 end 0049 0050 % Ensure that Length is defined and an even number 0051 if ~isfield(p.colorMap,'length'), 0052 p.colorMap.length = 40; 0053 else 0054 p.colorMap.length = fix(p.colorMap.length/2) * 2; 0055 end 0056 0057 0058 %A color map matrix may have any number of rows, but it must have 0059 %exactly 3 columns. Each row is interpreted as a color, with the 0060 %first element specifying the intensity of red light, the second 0061 %green, and the third blue. Color intensity can be specified on the 0062 %interval 0.0 to 1.0. 0063 0064 switch p.colorMap.style 0065 0066 case 'Gray' 0067 0068 R = linspace(p.colorMap.Cmin,p.colorMap.Cmax,p.colorMap.length); 0069 Gmap = [R' R' R']; % R=G=B 0070 p.colorMap.map = Gmap; 0071 0072 case 'Red/Blue' 0073 0074 X = linspace(p.colorMap.Cmin,p.colorMap.Cmax,p.colorMap.length); 0075 R = X .^ p.colorMap.exp; 0076 G = R .* 0; 0077 B = fliplr(R); 0078 0079 RBmap = [R' G' B']; 0080 p.colorMap.map = RBmap; 0081 0082 case 'Red/Blue/White' 0083 0084 Half = (p.colorMap.length / 2); 0085 0086 % Calculate the required exponent min/max so that 0087 % min/max R1 below will be 0/Cmax-Cmin 0088 Expmin = 0; 0089 Expmax = (p.colorMap.Cmax - p.colorMap.Cmin) .^ ( 1 / p.colorMap.exp ); 0090 0091 % Generate an array of values from Expmin to Expmax, using 0092 % half the length of the colormap 0093 X = linspace(Expmin,Expmax,Half); 0094 0095 % Now raise it to the power of exp 0096 R1 = X .^ p.colorMap.exp; 0097 0098 % Now add Cmin 0099 R1 = R1 + p.colorMap.Cmin; 0100 0101 % Translate the curve origin to zero and 0102 % reflect it about the X axis 0103 tmp = 0 - (R1 - p.colorMap.Cmin); 0104 % Reflect it about the y axis 0105 tmp = fliplr(tmp); 0106 % Now add the Cmax value 0107 tmp = tmp + p.colorMap.Cmax; 0108 0109 R1 = tmp(1:end-1); 0110 0111 Cmax = ones(size(R1)) * p.colorMap.Cmax; 0112 0113 R2 = fliplr(R1); 0114 0115 R = [ Cmax R2 ]; % Red array 0116 G = [ R1 R2 ]; % Green array 0117 B = fliplr(R); % Blue array 0118 0119 % Create colormap from Blue to Red 0120 Cmap = [B' G' R']; 0121 0122 % Add the max value into the middle of the cmap to 0123 % even up the zero color point 0124 tmp1 = Cmap(1:Half-1,:); 0125 tmp2 = [p.colorMap.Cmax p.colorMap.Cmax p.colorMap.Cmax]; 0126 tmp3 = Cmap(Half:end,:); 0127 Cmap = [ tmp1; tmp2; tmp3 ]; 0128 0129 p.colorMap.map = Cmap; 0130 0131 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0132 % Add pink or white tips to this colormap 0133 Expmin = 0; 0134 Expmax = (p.colorMap.Cmax - p.colorMap.Cmin) .^ ( 1 / 20 ); 0135 0136 X = linspace(Expmin,Expmax,length(Cmap)); 0137 B = X .^ 10; 0138 R = fliplr(B); 0139 % for white tips 0140 %G = B + R; Addmap = [R' G' B']; 0141 % for pink/white tips 0142 %G = X .^ 40; G = G + fliplr(G); Addmap = [R' G' B']; 0143 % for pink tips 0144 %G = X .* 0; Addmap = [R' G' B']; 0145 % yellow, cyan tips 0146 G = B + R; Addmap = [B' G' R']; 0147 0148 Addmap = (Cmap + Addmap); 0149 0150 index = find(Addmap > p.colorMap.Cmax); 0151 Addmap(index) = p.colorMap.Cmax; 0152 0153 p.colorMap.map = Addmap; 0154 0155 case 'default', 0156 0157 p.colorMap.map = jet; 0158 0159 otherwise 0160 0161 % get matlab colormap 0162 % this may not work under all circumstances, 0163 % when Style is not a matlab colormap 0164 p.colorMap.map = colormap(p.colorMap.style); 0165 %R = linspace(Cmin,Cmax,Length); B = fliplr(R); G = zeros(size(R)); 0166 %RBmap = [R' G' B']; 0167 %Map = RBmap; 0168 end 0169 0170 0171 % Plot colormap 0172 if (p.colorMap.plot), 0173 figure('NumberTitle','off','Name','EEG Toolbox Colormap'); 0174 colormap(p.colorMap.map); rgbplot(p.colorMap.map); colorbar 0175 axis tight 0176 end 0177 0178 return