unzip('formica 50x.asc.zip')
M = readmatrix('formica 50x.asc','FileType','text','Delimiter','\t');
% the file contains two sets of data separated by two lines of text that
% contain some description or something (lines 307208 and 307209, which
% correspond to NaNs in the first column of M), so split M into two
% matrices M1 and M2 using the locations of those NaN values.
idx = find(isnan(M(:,1)));
M1 = M(1:idx(1)-1,:);
M2 = M(idx(2)+1:end,:);
% find the number of consecutive repeated X values in each section of M1,
% and use that to get the number of distinct Y values.
nx = diff(find(diff(M1(:,1))));
assert(all(nx == nx(1)))
nx = nx(1);
ny = size(M1,1)/nx;
% use those sizes to reshape each column of M1.
X = reshape(M1(:,1),nx,ny);
Y = reshape(M1(:,2),nx,ny);
Z = reshape(M1(:,3),nx,ny);
% plot a surface.
figure
subplot(2,1,1)
surf(X,Y,Z,'EdgeColor','none')
xlabel('X')
ylabel('Y')
zlabel('Z')
% now do the same for M2.
nx = diff(find(diff(M2(:,1))));
assert(all(nx == nx(1)))
nx = nx(1);
ny = size(M2,1)/nx;
X = reshape(M2(:,1),nx,ny);
Y = reshape(M2(:,2),nx,ny);
Z = reshape(M2(:,3),nx,ny);
subplot(2,1,2)
surf(X,Y,Z,'EdgeColor','none')
xlabel('X')
ylabel('Y')
zlabel('Z')
