Project 1 - Parsing NASA thermodynamic data

Images were attached as files and also included in the report.

function M=molecular_weight(name)
atoms=['H','C','O','N','r'];

fprintf('molecular weight of');
fprintf(name);
fprintf(':');

atomic_wt=[1 12 16 14 40];
M=0;

for i=1:length(name)
    for j=1:length(atoms)
        if strcmp(name(i),atoms(j)) %strcmp commands compares the two quantities
            M=M+atomic_wt(j);
            position=j;
        end
    end
    n=str2num(name(i));

    if n>1
        M=M+atomic_wt(position*(n-1));

    end
    fprintf('%d',M);
    disp(' ');
end

clc
clear all


R=fopen('THERMO.dat','r'); %open the data file in read mode

f_line=fgetl(R); %first line in the file is ready by fgetl command.

%we see the files contains global temperatures in 2nd line so 
global_temp=fgetl(R);

%whole line is saved as a single string, so split it by 
temp_range=strsplit(global_temp,' ');

%converting string and allocating the temperatures accordingly
gl_min_t=str2num(temp_range{2});
gl_med_t=str2num(temp_range{3});
gl_max_t=str2num(temp_range{4});

T=linspace(gl_min_t,gl_max_t,79);

%assigning temperature range from min to maximum with equal spaccing of 79(random number)

r=8.314; %universal gas constant
molecular_wt=0;
tic
%skiping lines  
for i=3:5
    comments=fgetl(R);
end

%assingning the coefficients with respect to 53 different composition of gases.
for i=1:53 
l1=fgetl(R);
name=strtok(l1); %strtok command takes the first word in a line. so here it takes composition of gas.

%scanning next 3 lines;
l2=fgetl(R);
l3=fgetl(R);
l4=fgetl(R);

%finding a character to split the string
A=strfind(l2,'E');
B=strfind(l3,'E');
C=strfind(l4,'E');

%assigning the coefficients...
a1=str2num(l2(1:A(1)+3));
a2=str2num(l2(A(1)+4:A(2)+3));
a3=str2num(l2(A(2)+4:A(3)+3));
a4=str2num(l2(A(3)+4:A(4)+3));
a5=str2num(l2(A(4)+4:A(5)+3));
a6=str2num(l3(1:B(1)+3));
a7=str2num(l3(B(1)+4:B(2)+3));

%here, 1st 7 coefficients are of lower temperature and assigned by a 
% 2nd 7 terms are related to high temperature and assigned by b

b1=str2num(l3(B(2)+4:B(3)+3));
b2=str2num(l3(B(3)+4:B(4)+3));
b3=str2num(l3(B(4)+4:B(5)+3));
b4=str2num(l4(1:C(1)+3));
b5=str2num(l4(C(1)+4:C(2)+3));
b6=str2num(l4(C(2)+4:B(3)+3));
b7=str2num(l4(C(3)+4:B(4)+3));

%specific heat 
cp=spheat(a1,a2,a3,a4,a5,b1,b2,b3,b4,b5,T,r,gl_med_t);

%enthalpy
h=enthalpy(a1,a2,a3,a4,a5,a6,b1,b2,b3,b4,b5,b6,T,r,gl_med_t);

%entropy
s=entropy(a1,a2,a3,a4,a5,a7,b1,b2,b3,b4,b5,b7,T,r,gl_med_t);

molecular_wt(i)=molecular_weight(name);

plotting(cp, h, s, T, name);

end

toc

function plotting(cp, h, s, T, name)
cd(pwd)
dir_name = name;
mkdir(dir_name);

figure(1)
plot(T,cp,'linewidth',2,'color','b');
title(sprintf('specific heat Vs temperature of %s', name));
xlabel('temperature');
ylabel('specific heat');

figure(2)
plot(T,h,'linewidth',2,'color','r');
title(sprintf('Enthalpy Vs temperature of %s', name));
xlabel('temperature');
ylabel('enthalpy');

figure(3)
plot(T,s,'linewidth',2,'color','y');
title(sprintf('entropy Vs temperature of %s', name));
xlabel('temperature');
ylabel('entropy');

cd(dir_name)
saveas(1,'cp_vs_t.png');
saveas(2,'h_vs_t.png');
saveas(3,'s_vs_t.png');

cd ..
end

function s=entropy(a1,a2,a3,a4,a5,a7,b1,b2,b3,b4,b5,b7,T,r,gl_med_t)

if T<=gl_med_t
    s=r*(a1.*log(T)+ a2.*T + a3.*(T.^2) + a4.*(T.^3) + a5.*(T.^4)/4 + a7);

else
    s=r*(b1.*log(T)+ b2.*T + b3.*(T.^2) + b4.*(T.^3) + b5.*(T.^4)/4 + b7);

end

function cp=spheat(a1,a2,a3,a4,a5,b1,b2,b3,b4,b5,T,r,gl_med_t)
if T>=gl_med_t
    cp=r*(a1+ a2*T + a3*T.^2+ a4*T.^3+ a5*T.^4);
else
    cp=r*(b1+ b2*T + b3*T.^2+ b4*T.^3+ b5*T.^4);
end