To convert a number to a string --> num2str(numval, "val=%0.2f")


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Plot Magnitude and Phase of a DTFT - 4b
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% create the x-axis spanning -4*pi to 4*pi (256 divisions = 257 points)
wval = linspace(-4*pi, 4*pi, 257);

% remove the x-axis points that land on integer multiples of 2*pi
wcval = nonzeros(wval .* (abs(wval - (2*pi)*round(wval / (2*pi))) > 1.0e-8))';

% define the function in problem 4a
X = @(w) (2 ./ (1 - 0.75 * e.^(-j*w)));

% plot the magnitude and phase
subplot(2, 1, 1)
plot(wcval, abs(X(wcval)))
title("Problem 4b - Magnitude")
xlabel("Normalized Frequency")
ylabel("Magnitude")
xlim([-4*pi, 4*pi])
xticks(linspace(-4*pi, 4*pi, 5));
grid("on")

subplot(2, 1, 2)
plot(wcval, (180/pi)*angle(X(wcval)))
title("Problem 4b - Phase")
xlabel("Normalized Frequency")
ylabel("Phase [deg]")
xlim([-4*pi, 4*pi])
ylim([-180, 180])
xticks(linspace(-4*pi, 4*pi, 5));
yticks(linspace(-180, 180, 5));
grid("on")

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%




D = @(m) ((-2*j/7)*(3*sin(6*pi*m/7) + 2*sin(4*pi*m/7) + sin(2*pi*m/7)));

D0 = D(0);
D1 = D(1);
D2 = D(2);
D3 = D(3);
D4 = D(-3);
D5 = D(-2);
D6 = D(-1);

Wo = 2*pi/7;

F = @(n) (D0 + D1*e^(j*Wo*n) + D2*e^(j*2*Wo*n) + D3*e^(j*3*Wo*n) + D4*e^(j*4*Wo*n) + D5*e^(j*5*Wo*n) + D6*e^(j*6*Wo*n));



% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Plot Magnitude and Phase of a DTFT
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% create the x-axis spanning -4*pi to 4*pi (256 divisions = 257 points)
wval = linspace(-4*pi, 4*pi, 257);

% remove the x-axis points that land on integer multiples of 2*pi
wcval = nonzeros(wval .* (abs(wval - (2*pi)*round(wval / (2*pi))) > 1.0e-8))';

% define the function in problem 4a
X = @(w) ((1/4) .* (1 - e.^(-j.*w.*4)) ./ (1 - e.^(-j.*w)));

% plot the magnitude and phase
subplot(2, 1, 1)
plot(wcval, abs(X(wcval)))
title("Problem 4a - Magnitude")
xlabel("Normalized Frequency")
ylabel("Magnitude")
xlim([-4*pi, 4*pi])
xticks(linspace(-4*pi, 4*pi, 5));
grid("on")

subplot(2, 1, 2)
plot(wcval, (180/pi)*angle(X(wcval)))
title("Problem 4a - Phase")
xlabel("Normalized Frequency")
ylabel("Phase [deg]")
xlim([-4*pi, 4*pi])
ylim([-180, 180])
xticks(linspace(-4*pi, 4*pi, 5));
yticks(linspace(-180, 180, 5));
grid("on")

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% help
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
help

help history

help sinc

doc

doc sinc



% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% plotting syntax / keys
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
plot(x, y)
plot(x1, y1, lspec1,    x2, y2, lspec2,    ....)
plot(x, y, 'Name', Value)

color        --> 'red', 'green', 'blue', 'cyan', 'magenta', 'yellow', 'black', 'white'
             --> 'r',   'g',     'b',    'c',    'm',       'y',      'k',     'w'
             --> '#FF0000" ....

linestyle    --> '-'    (solid)
                 '--'   (dashed)
                 ':'    (dotted)
                 '-.'   (dash-dot)
                 'none' (no line)

linewidth    --> 0.5, 2.0, 8.0

linejoin     --> 'round', 'miter', 'chamfer'

marker       --> 'o', '+', '*', '.', 'x', 's', 'd', '^', 'v', '>', '<', 'p', 'h', 'none'

markermode   --> 'auto', 'manual'

markerindices --> 5 (every 5th point)

markersize    -->   6

displayname   --> 'measured', 'simulated'


% ---
xlim("auto")
xlim([-20 20])

xlabel("Time [ns]")
ylabel("Magnitude [V]")
title("Phase")

legend()



% ---

':' plots a dotted line.

'g:' plots a green, dotted line.

'g:*' plots a green, dotted line with star markers.

'*' plots star markers with no line.


xlabel("Greg")

subplot(2,1,1)

xlabel("Shan")

x = linspace(0,2*pi,50);
y = sin(x);
plot(x,y,':')

hold on
y2 = cos(x);
plot(x,y2,'--ro')
hold off

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% plot magnitude and phase of a frequency domain function
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

F = @(w) (1 ./ (1 .+ i .* w));

wval = -10:0.01:10;

subplot(2,1,1)

plot(wval, abs(F(wval)))

subplot(2,1,2)

plot(wval, 180/pi*angle(F(wval)))

hold on
cval = -10:1.0:10;

plot(cval, 180/pi*angle(F(cval)), 'ro')


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% define a function and plot it
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

u = @(t) ((t>=0)*1.0);

w = @(t, a, b) (u(t - a) - u(t - b))

x = @(t) (w(t,-1,0).*(-1-t) + w(t,0,1).*t + w(t,1,2).*1.0 + w(t,2,3).*(3-t))

figure

tvec = -3:0.025:5;

plot(tvec, x(tvec), 'b', tvec, x(-2*tvec-1), 'r');
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%




% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% niceplot.m
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

gfig = figure;

set(gca, 'linewidth', 2)
set(gca, 'fontsize', 14)


x = linspace(0,16*pi,500);
y = sin(x);
z = cos(x) .* e.^(-x/(4*pi));

hold on

gp = plot(x, y, '-', 'displayname', 'Jack')
hp = plot(x, z, '--', 'displayname', 'Andre')

xlabel('x', 'fontsize', 36)
ylabel('Sin(x)', 'fontsize', 36)
title('Sin(x) Graph', 'fontsize', 36)

% xlim auto
% ylim auto

% xlim([0 45])
% ylim([-1.2 1.2])

grid on
% axis equal

legend()
legend('boxoff')

set(gp, 'linewidth', 2)
set(hp, 'linewidth', 3)
% set(hp, 'linestyle', '--')

hold off

print(gfig, 'plot.pdf', '-dpdf');
print(gfig, 'plot.svg', '-dsvg');
print(gfig, 'plot.png', '-dpng', '-r300');

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%




* **************************************************

plot(x, y)
plot(x1, y1, lspec1,    x2, y2, lspec2,    ....)
plot(x, y, 'Name', Value)

color        --> 'red', 'green', 'blue', 'cyan', 'magenta', 'yellow', 'black', 'white'
             --> 'r',   'g',     'b',    'c',    'm',       'y',      'k',     'w'
             --> '#FF0000" ....

linestyle    --> '-'    (solid)
                 '--'   (dashed)
                 ':'    (dotted)
                 '-.'   (dash-dot)
                 'none' (no line)

linewidth    --> 0.5, 2.0, 8.0

linejoin     --> 'round', 'miter', 'chamfer'

marker       --> 'o', '+', '*', '.', 'x', 's', 'd', '^', 'v', '>', '<', 'p', 'h', 'none'

markermode   --> 'auto', 'manual'

markerindices --> 5 (every 5th point)

markersize    -->   6

displayname   --> 'measured', 'simulated'

* **************************************************




% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% nicerplot.m
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

gfig = figure;

x = linspace(0,16*pi,500);
y = sin(x);
z = cos(x) .* e.^(-x/(4*pi));

hold on

gp = plot(x, y, '-', 'displayname', 'Jack')
hp = plot(x, z, '--', 'displayname', 'Andre')

xlabel('x', 'fontsize', 16)
ylabel('Sin(x)', 'fontsize', 16)
title('Sin(x) Graph', 'fontsize', 16)
grid on
% axis equal


legend()
legend('boxoff')

set(gp, 'linewidth', 2)
set(hp, 'linewidth', 3)
% set(hp, 'linestyle', '--')

hold off

print(gfig, 'plot.pdf', '-dpdf');
print(gfig, 'plot.svg', '-dsvg');
print(gfig, 'plot.png', '-dpng', '-r300');

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%





* To run a script 

  -- put it in the file fname.m
  -- simply type fname at the command line




Use Octave

* Number format

  format hex

  format compact

  format longEng
  format long
  format shortEng

  


* Very C-Like syntax
  Note opening / writing / closing a file just like C



>> function y = gavg(x, y, z)
  y = (x + y + z) / 3;
end
>> gavg(1, 5, 4)
ans =  3.3333
>> fp = fopen('crapX.txt', 'w');
>> fprintf(fp, 'hello %f = gavg(%f, %f, %f)\n', gavg(1, 5, 7), 1, 5, 7);
>> fclose(fp);
>>





source /hwnet/common_r2/env/toolsetup.mathworks_r2017b

https://matlabacademy.mathworks.com/

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

* ans is the last calculation answer

* a = [1 2 3 4]

  a = [1 2 3; 4 5 6; 7 8 9]

  z = zeros(5, 1)

  a` --> transpose a


* inv(a) --> inverse of a
  det(a) --> determinite of a

  amazing :det(a) from above does not give 0

* format long
  format short

* A = [a,a] --> sideways concatenation
  A = [a;a] --> vertical concatenation

* A(4,2) --> element in row 4, col 2

  A(8) for a for a 4x4 matrix is last element in 2nd column


* A(1:3,2)

  A(3,:) --> row 3 of matrix A

* B = 0:10:100