lab_sea/matlab/seismic.m

function rgb = seismic(n);

% seismic(n) creates a colormap, ranging from dark blue via white to dark red.
%
% Nico Sneeuw
% Munich, 31/08/94

if nargin == 0, n = size(get(gcf,'colormap'),1); end

m = ceil(n/3);
top = ones(m,1);
bot = zeros(m,1);
up = (0:m-1)'/m;
down = flipud(up);

r = [bot; up; 1; top; down];
g = [bot; up; 1; down; bot];
b = [up; top; 1; down; bot];
rgb = [r g b];

% rgb-map has size 4m+1 now. The central part will be extracted.

xlarge = 4*m+1-n;
xblue = round(xlarge/2);
xred = xlarge - xblue;
rgb([1:xblue 4*m-xred+2:4*m+1],:) = [];
1	atn	1.1	function rgb = seismic(n);
2
3			% seismic(n) creates a colormap, ranging from dark blue via white to dark red.
4			%
5			% Nico Sneeuw
6			% Munich, 31/08/94
7
8			if nargin == 0, n = size(get(gcf,'colormap'),1); end
9
10			m = ceil(n/3);
11			top = ones(m,1);
12			bot = zeros(m,1);
13			up = (0:m-1)'/m;
14			down = flipud(up);
15
16			r = [bot; up; 1; top; down];
17			g = [bot; up; 1; down; bot];
18			b = [up; top; 1; down; bot];
19			rgb = [r g b];
20
21			% rgb-map has size 4m+1 now. The central part will be extracted.
22
23			xlarge = 4*m+1-n;
24			xblue = round(xlarge/2);
25			xred = xlarge - xblue;
26			rgb([1:xblue 4m-xred+2:4m+1],:) = [];