Continuous and repetitive gaussian random function in matlab

I want to create a random rough surface profile as input form my method. I can able to create random variation in numbers using randn function but each time i simulate i get different input data which changes output. If it is possible to store and use the data or to generate a continuous function of random data which can be repetative if done simulaion that would be helpful

[KALYAN ACHARJYA]

Hello Rakesh, can you show the plot you are looking for (use paint or any drawing tool)?

[RAKESH MAHARANA]

Its not any specific profile. The profile i want to generate is random but continuous. It should not change with simulation unless i change it . The two graps are profile i obtained using random function in matlab but every time i run in matlab profile changes so output changes

Answer 1

[Stephan]

If i understood you correctly, you want to get the same random values every time you run your code. This is reached by the rng function.

rand(1,10)

ans =

    0.4387    0.3816    0.7655    0.7952    0.1869    0.4898    0.4456    0.6463    0.7094    0.7547

s = rng

s = 

  struct with fields:

     Type: 'twister'
     Seed: 0
    State: [625×1 uint32]

rng(s)
rand(1,10)

ans =

    0.2760    0.6797    0.6551    0.1626    0.1190    0.4984    0.9597    0.3404    0.5853    0.2238

rng(s)
rand(1,10)

ans =

    0.2760    0.6797    0.6551    0.1626    0.1190    0.4984    0.9597    0.3404    0.5853    0.2238

[RAKESH MAHARANA]

Hi stephen, i understand your answer. I can repeat same random numbers if i use rng function. If i want to generate another set of numbers then? . I want to generate a set of random numbers within a specific limit and it should not change during continuous simulation but also after some point i want to generate another set and use it .

[RAKESH MAHARANA]

function [omega,sro1,sro3]=roughsurf(D);
% surface roughness calculation
% range of surface roughness
i=0;
k=0;% length point of slab
a=1;% constant input for random calculation
m1=0;% mean calculation of both height and diameter
m2=0;
ro1=0;
ro2=0;
s1=0;
s3=0;
sro1=0;% reflection coefficient value of roughness
sro3=0;

for i=0:0.01:D
    heigh1(a)=randn(1);
    diame1(a)=randn(1);
    m1=mean(heigh1);
    m2=mean(diame1);
    s1=std(heigh1);
    s3=std(diame1);
    sro1=std(heigh1-s1)/12000;
    sro3=std(diame1-s3)/12000;
    ro1=mean(heigh1-m1);
    ro2=mean(diame1-m2);
    if ((ro1~=0)&&(ro2~=0)) 
    om1(a)=atan(2*ro1/ro2);
    else
      om1(a)=atan(2*heigh1/diame1);
    end;
    k=om1(a);
    a=a+1;   
end
plot(om1);
sro3;
sro1;
omega=k;
end

Every time function is called for a specific value of D it is generating random numbers .For 1 main program simulation it should have more than 100 iterations of this loop, and also i am unable to generate plot inside the calling function