%  Numerical Modelling in Geosciences
%  by Manuele Faccenda, Università di Padova
%
%  Practice 1b
%
%  Produce, plot, save, load 2D data

clear all;
close all;

%% Produce 2D data
x=-10:0.1:10;
y=-10:0.1:10;
xnum=size(x,2);
ynum=size(y,2);

z=zeros(xnum,ynum);
for i = 1:xnum
    for j = 1:ynum
        z(i,j) = sin(x(i))+sin(y(j));
    end
end

%Plot 2D data
figure(1)
subplot(2,2,1)
%pcolor(x,y,z)
surf(x,y,z)
shading interp
colorbar
title('Plot function z')
xlabel('X')
ylabel('Y')

%% Text files: human readable

%Save data in ascii format to text file
fid=fopen('test.txt','w');
fprintf(fid,'%d \n',xnum);
fprintf(fid,'%d \n',ynum);
for i = 1:xnum
    fprintf(fid,'%e \n',x(i));
end
for i = 1:ynum
    fprintf(fid,'%e \n',y(i));
end
for i = 1:xnum
    for j = 1:ynum
        fprintf(fid,'%e \n',z(i,j));
    end
end
fclose(fid);

clear all;

%Read data in ascii format from text file
fid=fopen('test.txt','r');
xnum=fscanf(fid,'%d',1);
ynum=fscanf(fid,'%d',1);
x=zeros(1,xnum);
for i = 1:xnum
    x(i)=fscanf(fid,'%e',1);
end
y=zeros(1,ynum);
for i = 1:ynum
    y(i)=fscanf(fid,'%e',1);
end
z1=zeros(xnum,ynum);
for i = 1:xnum
    for j = 1:ynum
        z1(i,j)=fscanf(fid,'%e',1);
    end
end
fclose(fid);

subplot(2,2,2)
%pcolor(x,y,z1)
surf(x,y,z1)
shading interp
colorbar
title('Read and plot z1')
xlabel('X')
ylabel('Y')

%% Binary files: machine readable, much faster than in ascii format

%Save data in binary format
fid=fopen('test.bin','w');
fwrite(fid,xnum,'uint8');
fwrite(fid,ynum,'uint8');
for i = 1:xnum
    fwrite(fid,x(i),'single');
end
for i = 1:ynum
    fwrite(fid,y(i),'single');
end
for i = 1:xnum
    for j = 1:ynum
        fwrite(fid,z1(i,j),'single');
    end
end
fclose(fid);

clear all;

%Read data in binary format
fid=fopen('test.bin','r');
xnum=fread(fid,1,'uint8');
ynum=fread(fid,1,'uint8');
x=zeros(1,xnum);
for i = 1:xnum
    x(i)=fread(fid,1,'single');
end
y=zeros(1,ynum);
for i = 1:ynum
    y(i)=fread(fid,1,'single');
end
z2=zeros(xnum,ynum);
for i = 1:xnum
    for j = 1:ynum
        z2(i,j)=fread(fid,1,'single');
    end
end
fclose(fid);

subplot(2,2,3)
%pcolor(x,y,z2)
surf(x,y,z2)
shading interp
colorbar
title('Read and plot z2 ')
xlabel('X')
ylabel('Y')

%% HDF5: extremely useful when many different datasets must be saved/loaded
%  Path where to save/load data must be specified. It can be used also in C
%  and Fortran codes

%Save data in binary format to a hdf5 file
hdf5write('test.h5','/xnum',xnum)
hdf5write('test.h5','/ynum',ynum,'WriteMode','append')
hdf5write('test.h5','/Coordinates/x',x,'WriteMode','append')
hdf5write('test.h5','/Coordinates/y',y,'WriteMode','append')
hdf5write('test.h5','/Functions/z',z2,'WriteMode','append')

clear all;

%Read data from a hdf5 file
xnum=hdf5read('test.h5','/xnum');
ynum=hdf5read('test.h5','/ynum');
x=hdf5read('test.h5','/Coordinates/x');
y=hdf5read('test.h5','/Coordinates/y');
z3=hdf5read('test.h5','/Functions/z');

subplot(2,2,4)
%pcolor(x,y,z3)
surf(x,y,z3)
shading interp
colorbar
title('Read and plot z3')
xlabel('X')
ylabel('Y')

%Save image
filename = 'test.png';
printmod = 1;
if printmod>0
    print ('-dpng', '-r300','-zbuffer ',filename);
end

%% MatLab save/load functions: extremely easy to use, no need to specify path, but works only on MatLab

%Save data in bynary MatLab-file (but also in ascii format to text file, see manual)
save('test','z3','xnum','ynum')
clear all;
load('test','xnum')

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%%%                                Homework                                   %%%
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%%%   Study all the new functions by using the MatLab manual, many different  %%%
%%%   options are associated with these functions. Exercise producing/saving/ %%%                                                                       %%%
%%%   loading/plotting 2D data                                                %%%
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