How to read grid file GOT4.7 format ocean tide model?

Hi everyone,

I've tried to modify and got confused on the script that has given to me in order to read another format of grid file.

Can anyone help me to solve this matter? Attached here is an example of grid file to be read.

And also this is the script that had been given. I tried to modify and get confused on it.

clc;clear all; close all;

filename = 'k1.txt';
file ='K1GOT.txt';

fid = fopen(filename);
L = cell(5,1);
for K = 1 : 7; L{K} = fgetl(fid); end

longrange = sscanf(L{5}, '%f');
latrange = sscanf(L{4}, '%f');
widths = sscanf(L{3}, '%f');
indicates_missing = sscanf(L{6}, '%f');
%undefined = sscanf(L{7}, '%f');

per_line = 11;
partwidth = widths(1);
nparts = widths(2);
parts = cell(nparts,1);

colgroups = floor(partwidth / per_line);
leftover = partwidth - colgroups * per_line;
failed = false;

for P = 1 : nparts
  data1 = fscanf(fid, '%f', [per_line colgroups]);
  if isempty(data1); failed = true; break; end
  data1 = reshape(data1, [per_line colgroups]);
  data2 = fscanf(fid, '%f', [leftover]);
  data = [reshape(permute(data1, [1 3 2]), [], 2); data2];
  parts{P} = data;
end

if failed
    fprintf('Only got %d of %d parts successfully\n', P, npars);
end

if ~failed
  L = fgetl(fid);
  if ischar(L) && ~isempty(L)
    fprintf('Not empty at apparent EOF, content is:\n%s\n', L);
    failed = true;
  end
end

if ~failed
    lats = linspace(latrange(1), latrange(2), widths(2));
    longs = linspace(longrange(1), longrange(2), widths(1));
    data = permute(cat(3, parts{:}),[1 3 2]);
    amps = data(:,:,1) .';
    amps(amps == indicates_missing(1)) = nan;
    phases = data(:,:,2) .';
    phases(phases == indicates_missing(2)) = nan;
    
    subplot(2,1,1);
    [xq,yq] = meshgrid(0:.25:360, -90:.25:90);
    surf(xq,yq,amps, 'edgecolor', 'none');
    xlim(longrange);
    ylim(latrange);
    xlabel('long'); ylabel('lat'); zlabel('amp');
    title('amplitudes');

    
    subplot(2,1,2);
    [xq,yq] = meshgrid(0:.25:360, -90:.25:90);
    surf(xq,yq,phases,'edgecolor', 'none')
    xlim(longrange);
    ylim(latrange);
    xlabel('long'); ylabel('lat'); zlabel('phase');
    title('phases');

end
Model = [yq(:) xq(:) amps(:) phases(:)];
    fid1 = fopen(file, 'wt');
    fprintf(fid1,'%.4f \t %.4f \t %.3f \t %.3f\n',Model.');
    fclose(fid1);

fclose(fid);

I shall be most grateful if anyone can solve my problem. Thank you.