Programming in MATLAB

% Homework #11 MATLAB
% File: HW_11_liu2102.m
% Date: 17 November 2017
% By: Erica Liu
% liu2102
% Section: 2
% Team: 35
%
% ELECTRONIC SIGNATURE
% Erica Liu
%
% The electronic signature above indicates that the program
% submitted for evaluation is my individual work. I have
% a general understanding of all aspects of its development
% and execution.
%
% This program will calculate the max distance of a crate pushed by
% a man, given that the mass is 60 kg, distance before man falls is 8 m, 
% the angle of the ramp is 30 degrees, and gravity is 9.81 m/s. The 
% program will plot 2 lines for the max distance that the crate moves 
% versus the constant force that the man exerts with different coefficients
% of restitution. The program will calculate this 
% with different amounts of force in which a for loop will account for. 

clc
clear

%set the different forces
force = 480:600;
i = 1;

% loop that calculates the distance with different amounts of force,
% one line per coefficient of restitution
for f = force
    A(i) = distance(f , 0.36);
    B(i) = distance(f, 0.42);
    i = i + 1;
end

%make the graphs
f1 = figure;
plot(force,A,'b',force,B,'r');
title('Max Distance vs Force Exerted');
xlabel('Force Exerted');
ylabel('Max Distance');
legend('u = 0.36','u = 0.42');


%user-defined function: calculate velocity, used from homework problem #5
function velocity = finalVel(force, coeff)
   rightSide = (force * 8) - (coeff * 60 * 9.81 * 8 * cos(30 / 180 * pi));
   pe = 9.81 * 60 * 8 * sin(30 / 180 * pi);
   variable = rightSide - pe;
   ke = 30;
   velocity = sqrt(variable / ke);
end

%user-defined function: calculate distance, used from homework problem #5
function totDist = distance(force, coeff)
    pe = 294.3;
    friction = coeff * 60 * 9.81 * cos(30 / 180 * pi);
    changeDist = (30 * (finalVel(force, coeff))^2) / (friction + pe);
    totDist = 8 + changeDist;
end

% Graph the approximated and actual factorial scatter plots
figure
pointsize = 20;
h1 = scatter(integers, approximated, 'r');
hold on
h2 = scatter(integers, actual, 'b');
hold off
xlabel('Integer');
ylabel('Approximated/True Value');
legend([h1, h2], {'Approximation', 'Factorial'})

% Graph the percent error scatter plot
figure
h3 = scatter(integers, error, 'g');
xlabel('Integer');
ylabel('Percent Error');
legend(h3, 'Percent Error');

% Homework #8 MATLAB
% File: HW12_Problem8_liu2102.m
% Date: 1 December 2017
% By: Erica Liu
% liu2102
% Section: 2
% Team: 35
%
% ELECTRONIC SIGNATURE
% Erica Liu
%
% The electronic signature above indicates that the program
% submitted for evaluation is my individual work. I have
% a general understanding of all aspects of its development
% and execution.
%
% This program will predict the concentration of dissolved oxygen (DO) in 
% mg/L in the Wabash in a given amount of days using a given formula. 
% It will indicate whether the concentration is between a certain range.

clc
clear all

%constants given by the problem
dosat = 9; 
k1 = 0.2;
k2 = 0.4;
l0 = 25;
d0 = 4;

%print the first 3 lines
fprintf('DO in Wabash in mg/L:\n');
fprintf('Day    DO\n');
fprintf('-----------\n');

for t =1:20
    %calculate the DO based off of the formula given
    total = dosat - ((k1*l0)/(k2-k1))*(exp(-k1*t)-exp(-k2*t))-d0*exp(-k2*t);
    
    total = round(total,2); %round the calculation to 2 decimal places
    
   if total >= 6 && total <= 8 %determine whether the value is between 6 and 8
       inRange = " *";
    else
       inRange = " ";
   end
   
   fprintf('%2d     %.2f%s\n', t, total, inRange); %print result
end