How to generate Pattern in MATLAB

Hello everyone, I hope you are doing well.

I have the following pattern as shown in the image.

I want to generate this kind of pattern, my Y axis has random value from 1 to 1000 and X-axis has also same random 1 to value from 1000.

How can i generate it .

Answer 1

[Jon]

For the first plot you show, you could do something like this (you can adjust the exact scaling)

x=linspace(0,0.1)
xr = 0.1/3
y = mod(x,xr)*(850 - 410)/xr + 410
plot(x,y,'o')
ylim([300,900])

For the second plot the slopes are negative and the lines start at 850 so

y = mod(x,xr)*(410 - 850 )/xr + 850

[Jon]

Here are the first and second figures from the code above:

[Stephen john]

@Jon Thanks for you answer, I want my x axis has 1000 values.

and also can this shape randomly generated in the above code you just putt (850 - 410)

I want it to be random.

[Stephen john]

@Jon i want 1000 samples in my array how can i do that?

[Jon]

Replace the first line in the code above with the following

x = linspace(0,0.1,1000)

Answer 2

[Scott MacKenzie]

Here's code to generate the patterns in the image posted:

f = figure('color', 'w', 'Units','normalized','Position',[.25 .3 .4 .3]);
tiledlayout(1,2);

nexttile;
y1 = repmat(linspace(420, 850, 25),1,3);
x1 = linspace(0, 0.1, 75);
p = plot(x1,y1, 'o', 'MarkerSize', 4);
xlabel('Time (s)'); ylabel('PRI (usec)');
xticks([0 .05 .1]);
set(gca, 'ylim', [300 900], 'YGrid', 'on','XGrid', 'on');
set(p, 'MarkerFaceColor', get(p,'Color'));

nexttile;
y2 = repmat(linspace(850, 420, 25),1,4);
x2 = linspace(0, 0.1, 100);
p = plot(x2,y2, 'o', 'MarkerSize', 4);
xlabel('Time (s)'); ylabel('PRI (usec)');
xticks([0 .05 .1]);
set(gca, 'ylim', [300 900], 'YGrid', 'on', 'XGrid', 'on');
set(p, 'MarkerFaceColor', get(p,'Color'));

[Stephen john]

@Scott MacKenzie Thanks for you answer, I want my x axis has 1000 values.

and also can this shape randomly generated in the above code you just putt (850 - 410) I want it to be random. for example some time it between 210 to 500 and some time it between 350 to 600

[Stephen john]

@Scott MacKenzie you repat 4 times but i want 1000 samples in my array how can i do that?

Answer 3

[Simon Chan]

Try the following and you may adjust the numLines to 1000 (Following demo is using 100).

Nx = 1000;
Ny = 1000;
numLines = 100;                 % Number of pattern (line) you required
lengthLine = 400;               % Length of each pattern (line)
numPt = 20;                     % Number of points for each pattern (line)
angle = 60;                     % Angle of pattern (line)
s= 0;
f = figure;
ax = gca;
while s<numLines
	xy1 = rand(1,2);
	x1 = Nx * xy1(1);
	y1 = Ny * xy1(2);
	x2 = x1 + lengthLine * cosd(angle);
	y2 = y1 + lengthLine * sind(angle);
    if all([y1 y2] <= Ny) && all([x1 x2] <= Nx) && all([y1 y2] >= 1) && all([x1 x2] >= 1)
        s = s+1;
        xx = linspace(x1,x2,numPt);
        yy = linspace(y1,y2,numPt);
        plot(xx,yy,'o','MarkerSize',3);
        hold on;
        drawnow
    end
end
ax.XLim = [1 Nx];
ax.YLim = [1 Ny];
grid(ax,'on');

[Stephen john]

@Simon Chan it is not my requirement. i want it a simple also the samples are overlapping

[Simon Chan]

May be this? Just don't quite understand about random on x-axis...

Ny = 1000;
numLines = 21;
numPt = 25;
f = figure;
ax = gca;
x1 = 0;
x2 = 1/30;
xdelta = 1/(30*numPt);
for k = 1:numLines
    ylength = randi([1 Ny-1]);          % Length of each line
    ystart = randi([1 Ny-ylength]);     % Start position
    yend = ystart + ylength;            % End position
    xx = linspace(x1,x2,numPt);
    yy = linspace(ystart,yend,numPt);
    plot(xx,yy,'o','MarkerSize',3);
    hold on;
    x1 = x1+1/30+xdelta;
    x2 = x2+1/30;
end
ax.YLim = [0 Ny];
grid(ax,'on');