Project 1 - Parsing NASA thermodynamic data

% program for Nasa Thermodynamics

f1 = fopen('THERMO.dat','r');
fgetl(f1);

% Defining temperature values

templ = str2num (fgetl(f1)); %#ok<ST2NM>
global_low_temp = templ(1);
global_mid_temp = templ(2); 
global_high_temp = templ(3);

% For skipping unwanted lines

for i=1:3 
    fgetl(f1);

end

%Loop creation to read the values and plot molecular weight

 for i= 1:4:212 
    line1 = fgetl(f1);

l = strsplit(line1, ' ');
m = length(l);
species = l{1};

%Storing the values of the local temperature values

low_temp = str2double(l(m-3));
mid_temp = str2double(l(m-2));
high_temp = str2double(l(m-1)); % Check this later

%Storing the values of the second line of variables

line2 =fgetl(f1); 
% Finding the position of E

a = strfind(line2, 'E');

%Reading all the other variables

a1 = str2double (line2(1:(a(1)+3)));
a2 = str2double (line2((a(1)+4):(a(2)+3))); 
a3 =str2double(line2 ((a(2)+4):(a(3)+3)));
a4 = str2double(line2((a(3)+4):(a(4)+3)));
a5 =str2double (line2((a(3)+4):(a(5)+3)));

% Storing the values of the 3rd line

line3=fgetl(f1);

%Finding the position of E

b = strfind(line3, 'E');

%Storing the values for the next set of variables

a6 =str2double(line3 (1:b(1)+3));
a7 = str2double(line3((b(1)+4):(b(2)+3)));
a8 =str2double(line3((b(2)+4):(b(3)+3)));
a9 =str2double(line3((b(3)+4):(b(4)+3)));
a10 =str2double(line3((b(4)+4):(b(5)+3)));

%Storing ther values of the 4th line

line4 = fgetl(f1);

%Finding the position of E

c=strfind (line4, 'E');

%Storing the values of variables in line 4
a11 =str2double(line4(1:c(1)+3)); 
a12 =str2double(line4((c(1)+4):(c(2)+3)));
a13 =str2double(line4((c(2)+4):(c(3)+3)));
a14 = str2double(line4((c(2)+4):(c(4)+3)));

%Creating Temperature values for Lower and higher temperature

lower_temp  = linspace(low_temp,mid_temp, 100);
higher_temp = linspace(mid_temp,high_temp, 100);

%Value of the universal has constant in j/mol*k 
R = 8.314; %Universal Gas Constant

%Calculating the values for cp, H and S using the given formulas

for k= 1:100.

%lower temperature values for cp,h,s calculations

cp_low(k)=(a8+(a9*lower_temp(k))+(a10*(lower_temp(k)^2)+(a11*(lower_temp(k))^3)+a12*(lower_temp(k))^4))*R;
h_low(k)=(a8+(a9*lower_temp(k))/2+(a10*lower_temp(k)^2)/3+(a11*lower_temp(k)^3)/4+a12*(lower_temp(k)))*R*lower_temp(k);
s_low(k)=((a8*log(lower_temp(k))+(a9*lower_temp(k))+((a10*lower_temp(k)^2)/2)+((a11*lower_temp(k)^3)/3)+((a12*lower_temp(k)^4)/4)+a14)*R);

%higher temperature values for cp,h,s calculations

cp_high(k)=(a1+(a2*higher_temp(k))+(a3*(higher_temp(k)^2)+(a4*(higher_temp(k))^3)+a5*(higher_temp(k))^4))*R; 
h_high(k)=(a1+(a2*higher_temp(k))/2+(a3*higher_temp(k)^2)/3+(a4*higher_temp(k)^3)/4+(a5*(higher_temp(k)^4))/5+(a6/higher_temp(k)))*R*higher_temp(k);
s_high(k)=(((a1*log(higher_temp(k)))+a2*higher_temp(k)+((a3*higher_temp(k)^2)/2)+((a4*higher_temp(k)^3)/3)+((a5*higher_temp(k)^4)/4)+a7)*R);

end

%Making Folders for saving the plots

nasa_graphs = species;
mkdir(nasa_graphs);
current =pwd; 
cd(nasa_graphs);

%Plotting the graphs:

%For specific heat

figure(1)

plot(lower_temp,cp_low,'linewidth',3)
hold on
plot(higher_temp, cp_high,'linewidth',3)
hold off
title(['Temperature vs Specific Heat',species,'O2'])
xlabel('Temperature'); 
ylabel('Specific Heat');
legend('low temperature','high temperature');
fig= sprintf('Specific Heat of %s.png',species);
saveas(gca,fig);

%For Enthalpy
figure(2)

plot(lower_temp,h_low,'linewidth',3)
hold on
plot(higher_temp,h_high,'linewidth',3) 
hold off 
title(['Temperature vs Enthalpy', species,'N2'])
xlabel('Temperature'); 
ylabel('Enthalpy');
legend ('Low temperature', 'high temperature'); 
fig =sprintf('Enthalpy of %s.png', species);
saveas(gca,fig);

%For Entropy
figure(3)
plot(lower_temp,s_low,'linewidth',2)
hold on
plot(higher_temp,s_high,'linewidth',2)
hold off
title(['Temperature vs Entropy', species,'CO2'])
xlabel('Temperature');
ylabel('Entropy'); 
legend('low temperature', 'high temperature'); 
fig =sprintf('Entropy of %s.png', species); 
saveas (gca,fig);
cd(current)
end

%Calculating molecular weight

atoms = ['H', 'C', 'N', 'R', 'S'];
atom_weigh= [1.00784 12.0109 16.002 39.065 32.867];
mol_weight = 0;
species_check= char(species);
for i=1:length(species_check)
 for j=1:length(atoms) 
   if (strcmp(species_check(i),atoms(j))) 
        mol_weight = mol_weight+ atom_weight(j); 
        position = j;

  end

end

x= str2double(species_check(i));
if x>1
mol_weight = mol_weight+(atom_weight(j)*(x-1));
end
fprintf('Molecular weight of %s is :%f\n' ,species_check, mol_weight)
end

EXPLAINATION:

1. The code uses the thermodynamic data values from the file thermo.dat that was provided to me.

2. This file was read with the help of the read command for files and was read line by line 

3. For getting values for various species the program used loops for manipulating the values to an extent of the number of iterations that have to be taken into account.
 
4. the co-efficients are arranged ina fixed order and we have found the exact positions with the help o command in matlab and using the find variable to be E

5. We have made a folder with the help of mkdir command

6. We have assigned certain values to the variables in the file and plotted themp against various temperature values vs enthalpy, entropy.

7. The images were saved in JPEG format with the help of the saveas command,