y=exp(-1.5*x).*sin(10*x)

%Que?!

%This is yx1.m
%by/ARG

%Plotting

%To plot the graph of a function you need to:
%Define your axis: X,Y,Z? R, Theta? What system of coordinates do you
%adopt? why?

%So specify X with a range of values
%Define the function y = f(x) or how x and y are related
%Call the plot command, as plot(x,y)

x = [0:5:100];
y = x;
plot(x,y)
title('x goes to 100,whats with the 5?,and thats the curve?')

%Plot y = x^2 or a parabola that is concave up,
%reducing increments by marging of twenties rather than by tenths?

x = [1 2 3 4 5 6 7 8 9 10];
x = [-100:20:100];
y = x.^2;
plot(x, y)

%adding labels

x = [0:0.01:10];
y = sin(x);
plot(x, y), xlabel('x'), ylabel('Sin(x)'), title('Sin(x) Graph'),
grid on, axis equal

% multifunction [thinking of strings yet?]

x = [0 : 0.01: 10];
y = sin(x);
g = cos(x);
plot(x, y, x, g, '.-'), legend('Sin(x)', 'Cos(x)')

% multi polynomials

x = [-10 : 0.01: 10];
y = 3*x.^4 + 2 * x.^3 + 7 * x.^2 + 2 * x + 9;
g = 5 * x.^3 + 9 * x + 2;
plot(x, y, 'r', x, g, 'g')

%for axis scales:
%axis ( [xmin xmax ymin ymax] )

%as in:
x = [0 : 0.01: 10];
y = exp(-x).* sin(2*x + 3);
plot(x, y), axis([0 10 -1 1]) %limits defined for x and y, respectively.

%Now that's an interesting plot,
%because x is defined twicely, than y, is the exponential times a sinal
%wave.... and man doesnt that sound like music?

%so far I'm saving time by only plotting the last line in this code..
%how could I count?

%The Syntax for the Command Subplot?
%subplot(m, n, p)
%m and n, rows and columns of plot array, and p, where exactly to place it.

%For example: (changing a few values from the tutorial for tests)

x = [0:0.01:5];
y = exp(-1.5*x).*sin(10*x);
subplot(1,2,1)
plot(x,y), xlabel('x'),ylabel('exp(–1.5x)*sin(10x)'),axis([0 5 -1 1])
y = exp(-2*x).*sin(10*x);
subplot(1,2,2)
plot(x,y),xlabel('x'),ylabel('exp(–2x)*sin(10x)'),axis([0 5 -1 1])

%Have you ever thought why are the limits on the y axis between 1 and -1??
%What do you know? What is x actually representing in this curve?
%Often in plots like this, we have amplitudes being
%y = Amplitude
%x = time... and the equation is the amplitude of a signal over time... but
%expressed as exponentials of sinusoidal functions.... how about that?


%Hahaha got the graph and can see some things
%At a smaller value... 1.5 we have more ripples (about 7 visible) vs. 5.
%The wave seems bigger, perhaps the reason why it ripples longer... now why
%would that be mathematically?