How to generate Pattern in MATLAB

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Stephen john
Stephen john on 16 Mar 2022
Commented: Jon on 17 Mar 2022
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 .

Answers (3)

Jon
Jon on 16 Mar 2022
Edited: Jon on 16 Mar 2022
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
  4 Comments
Stephen john
Stephen john on 17 Mar 2022
@Jon i want 1000 samples in my array how can i do that?
Jon
Jon on 17 Mar 2022
Replace the first line in the code above with the following
x = linspace(0,0.1,1000)

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Scott MacKenzie
Scott MacKenzie on 16 Mar 2022
Edited: Scott MacKenzie on 16 Mar 2022
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'));
  2 Comments
Stephen john
Stephen john on 17 Mar 2022
@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
Stephen john on 17 Mar 2022
Edited: Stephen john on 17 Mar 2022
@Scott MacKenzie you repat 4 times but i want 1000 samples in my array how can i do that?

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Simon Chan
Simon Chan on 17 Mar 2022
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');
  2 Comments
Stephen john
Stephen john on 17 Mar 2022
@Simon Chan it is not my requirement. i want it a simple also the samples are overlapping
Simon Chan
Simon Chan on 17 Mar 2022
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');

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