How can i generate data randomly in MATLAB

Hello Everyone, I hope you are doing well

I have the following code. which generate 5 level of different values.as you can see in plot

I want to generate random level upto 32 for random value from 1 to 1000

How can i do that in matlab

VALUE = [100 300 600 700 1000 ];
out2 = repmat(VALUE,1,ceil(4000/numel(VALUE)));
scatter(1:length(out2),out2)

[KSSV]

What do you mean by upto 32?

Answer 1

[Arif Hoq]

try this:

VALUE=1:(1000-1)/31:1000

VALUE = 1×32

1.0000 33.2258 65.4516 97.6774 129.9032 162.1290 194.3548 226.5806 258.8065 291.0323 323.2581 355.4839 387.7097 419.9355 452.1613 484.3871 516.6129 548.8387 581.0645 613.2903 645.5161 677.7419 709.9677 742.1935 774.4194 806.6452 838.8710 871.0968 903.3226 935.5484

out2 = repmat(VALUE,1,ceil(4000/numel(VALUE)));
scatter(1:length(out2),out2);

[Med Future]

@KSSV @Arif Hoq

like this code but i want to save results row

Now my result of each row is over writting

level=randi(5, 1, 3);
for i = 1:length(level)
prf = rand(1,level(i))*1000;

out2 = repmat(prf,1,ceil(1000/numel(prf)));
end
scatter(1:length(out2),out2)

[Med Future]

@KSSV @Arif Hoq

Now my result of each row is over writting. i want to avoid overwritting

and each row should be shape of 1x1000

[KSSV]

level=randi(5, 1, 3);
out2 = cell([],1) ; 
for i = 1:length(level)
prf = rand(1,level(i))*1000;

out2{i} = repmat(prf,1,ceil(1000/numel(prf)));
end

[Med Future]

@KSSV i dnt want cell array i want numeric array

[Walter Roberson]

I suspect more like

VALUE = sort(randi([100 1000], 1, 32));

out2 = repmat(VALUE,1,ceil(4000/numel(VALUE)));
scatter(1:length(out2),out2);

[Med Future]

@Walter Roberson i have the code its working

i just want to save results in each row

and row have shape of 1x1000

level=randi([2 32], 1, 100);


for i = 1:length(level)
prf=randi([1 1000], 1,level(i));
out2= repmat(prf,1,ceil(1000/numel(prf)));

end

[Med Future]

@KSSV @Walter Roberson some time the shape is 1x1023, 1x1051

i want to shape of each row 1x1000 and save results row wise

[Med Future]

@KSSV @Walter Roberson

i have used the following code but it gives the following err

Unable to perform assignment because the size of the left side is 1-by-1005 and the size of the right side is 1-by-1000.

level=randi([2 32], 1, 100);
[M,N]=size(level);
for j = 1:size(level,2)
prf=randi([1 1000], 1,level(j));
size(prf)
out2(j,:)= repmat(prf,1,ceil(1000/numel(prf)));
 
end

[Walter Roberson]

Your code asked for ceil(4000/32) each, not 1000 each. And the code I posted would not create a different number for each value.

[Med Future]

@Walter Roberson

Now this code is working, I want to reshape it into 1x1000

every row has 1000 samples

Can you please help me

level=randi([2 32], 1, 100);
[M,N]=size(level);
for j = 1:size(level,2)
prf=randi([1 1000], 1,level(j));
size(prf);
out = repmat(prf,1,ceil(1000/numel(prf)));
out2(j,1:length(prf)*ceil(1000/numel(prf)))=out;
end

[Med Future]

@Walter Roberson what can i change in this out = repmat(prf,1,ceil(1000/numel(prf))); command to generate row of 1x1000

[Walter Roberson]

You cannot do that using repmat. For example if 17 were generated for level you would be asking what integer number of copies of 17 elements can you take to get exactly 1000. And you just cannot do that, as 17 does not divide exactly into 1000. But you can use the out that you are currently generating with that code and take the first 1000 entries using indexing.

[Med Future]

@Walter Roberson so i cant reshape it into 1000?

[Walter Roberson]

level = 17; %randi([2 32], 1, 100);
[M,N]=size(level);
for j = 1:size(level,2)
prf=randi([1 1000], 1,level(j));
size(prf)
out = repmat(prf,1,ceil(1000/numel(prf)))
whos
end

ans = 1×2

1 17

out = 1×1003

941 438 290 294 399 989 876 941 501 786 405 23 422 262 95 118 716 941 438 290 294 399 989 876 941 501 786 405 23 422

  Name       Size              Bytes  Class     Attributes

  M          1x1                   8  double              
  N          1x1                   8  double              
  ans        1x2                  16  double              
  j          1x1                   8  double              
  level      1x1                   8  double              
  out        1x1003             8024  double              
  prf        1x17                136  double              

Notice that out is length 1003. You cannot reshape() 1003 into 1000.

What you can do is

out = out(1:1000);

and you could reshape() that