How to filter noisy function ?

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Yasemin Derme 2018-8-10

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https://ww2.mathworks.cn/matlabcentral/answers/414368-how-to-filter-noisy-function

评论： Yasemin Derme 2018-8-12

I have a gaussian function which outputs a 1-by-1001 matrix. It also has a noise. I want it to work 1000 times and to choose matrices with relatively less noise. Then, I want to create another matrix composed of the relatively less noisy matrices. How can I achieve this ?

    function [gf] = two_stars_random(C1,x01,s1,C2,x02,s2,N)
randCoeff=0.5;
a=(1-randCoeff)+2*randCoeff*rand(1);
C1t = a*C1;
a=(1-randCoeff)+2*randCoeff*rand(1);
x01t = a*x01;
x02t = x02+(x01t-x01);
a=(1-randCoeff)+2*randCoeff*rand(1);
s1t=a*s1;
a=(1-randCoeff)+2*randCoeff*rand(1);
C2t = a*C2;
a=(1-randCoeff)+2*randCoeff*rand(1);
s2t=a*s2;
N=1000;
range_begin = 0;
range_end   = 1;
x=range_begin:(1.0/N):range_end; 
g1=C1t*exp(-(x-x01t).^2/(2*s1t^2));
g2=C2t*exp(-(x-x02t).^2/(2*s2t^2));
b=0.2*rand(1)*(C1t+C2t)*rand(1,N+1);
gf=g1+g2+b;
end

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Yasemin Derme 2018-8-12

Okay, thanks a lot for your help.

function [gf] = two_stars(C1,x01,s1,C2,x02,s2,N)

C1=27.8498 ; % either expands (C1>1) or shrinks (0<C1<1) the curve vertically, reflects with respect to x axis when C1<0

C2=54.6882; % either expands (C2>1) or shrinks (0<C2<1) the curve vertically, reflects with respect to x axis when C1<0

x01=95.7507; % either shift right(x01>0) or left(x01<0)

x02=96.4889; % either shift right(x02>0) or left(x02<0)

s1=15.7613; %either expand (if s1 increases) or shrink (if s1 decreases) the curve horizontally

s2=97.0593; %either expand (if s2 increases) or shrink (if s2 decreases) the curve horizontally

N=10000;

range_begin = -50;%start from x1 point

range_end = 50;%ends in x2 point

x=range_begin:(1.0/N):range_end;%determines the rate with which the function will take into account the points

g1=C1*exp(-(x-x01).^2/(2*s1^2));%gaussian function

g2=C2*exp(-(x-x02).^2/(2*s2^2));%gaussian function

gf=g1+g2;%the sum of two gaussian functions

plot(g1+g2+ 0.5*rand(size(x)))

Yasemin Derme 2018-8-12

在 MATLAB Online 中打开

This is the function that I've been working on:

t=1001;

A = zeros(t-1,t);

for i =1:t-1

    stack(i,:) = two_stars_random(C1,x01,s1,C2,x02,s2,N);
    if b<0.1
       A = stack(i,t);
    elseif b>0.1
       A = zeros(1,t);
    end
    [r,~]=size(A);
    filtered(r,t) = A;
end