choose a part of matrix with an condition

i have the following code:

clc; clear all; close all;

lamda=1;

n=100;m=10;

for i=1:n

u=rand;

t(i)=-log(1-u)./lamda;

end

aa=min(t);aaa=max(t);

alpha=(t-aa)./(aaa-aa);

cut=alpha';

x=t';

fs =sort([x cut]);

result the follwling fuzzy set

0.0251095217432329 0

0.0259813666329032 0.000157215256236631

0.0343724949438669 0.00167034379911478

0.0365119840971735 0.00205614675493619

0.0444796386769595 0.00349291248150910

0.0685101096620772 0.00782620237994602

0.0729419959197381 0.00862538138743353

0.0729823212975833 0.00863265305316889

0.0771056967721968 0.00937619991509561

0.0782934192059375 0.00959037572660854

0.0942481070214086 0.0124674016320231

0.118104923234842 0.0167693772683126

0.132928037723898 0.0194423524388193

0.141464614937633 0.0209817090261459

0.150486651883491 0.0226086060430634

0.160165769148197 0.0243539909377214

0.162624667685636 0.0247973913271754

0.174022001792908 0.0268526133320516

0.177437098264183 0.0274684399236455

0.186089797358388 0.0290287361659603

0.192389357916822 0.0301647031700760

0.193639507619337 0.0303901361664079

0.198540620337461 0.0312739283420046

0.230425224929311 0.0370235133201386

0.243585467389849 0.0393966314230066

0.246461893804786 0.0399153224438845

0.277901483165116 0.0455846601389507

0.291537135509796 0.0480435064345724

0.309915334323799 0.0513575514785294

0.319423270431970 0.0530720681651994

0.334011019687199 0.0557026011467529

0.357922356879197 0.0600144082676525

0.364889059485256 0.0612706775287480

0.365435326188982 0.0613691829633927

0.443159715125493 0.0753848179315693

0.449823839934316 0.0765865249115897

0.468569891981819 0.0799669030166767

0.513582634608457 0.0880838168734941

0.554022281661509 0.0953760881810300

0.581646474411458 0.100357415241576

0.588036425496520 0.101509681899418

0.601783323397470 0.103988588527837

0.613498559211000 0.106101136094633

0.638552105558661 0.110618911854234

0.638916426867956 0.110684608021834

0.651875003547725 0.113021360782915

0.687205861775114 0.119392390762089

0.691297023750098 0.120130128731106

0.705899157309337 0.122763255559417

0.823433299288465 0.143957576323044

0.858045642838051 0.150199040285924

0.888157505568769 0.155628955940717

0.889518685776218 0.155874410490757

0.893463294721270 0.156585721313814

0.915285437208968 0.160520794815401

0.937878900953337 0.164594956669108

0.955028908877928 0.167687528435336

0.978256016710709 0.171875952033193

0.992685558782281 0.174477956335836

1.08909370982563 0.191862736987945

1.11174608686031 0.195947522369003

1.11550892269812 0.196626054992669

1.11575884057759 0.196671121384552

1.25770274616163 0.222267127912803

1.28429691903436 0.227062716843958

1.29259304165275 0.228558713504230

1.35119807040169 0.239126653651248

1.37659600127880 0.243706530482590

1.37747485674277 0.243865009919242

1.45006245198353 0.256954353586431

1.52626623667126 0.270695785896039

1.52631887410864 0.270705277731460

1.53674879873361 0.272586051813950

1.55574556165166 0.276011639306878

1.56381957936798 0.277467584944880

1.59033309595797 0.282248629547901

1.75485836515092 0.311916615975340

1.77673375075387 0.315861290531090

1.94447021196261 0.346108334519763

1.97521587492537 0.351652540075276

2.05646098147899 0.366303047747151

2.08463410738727 0.371383361070237

2.18820048893875 0.390058948214269

2.21500819936291 0.394893043261894

2.23664670373312 0.398795002256487

2.38362299297179 0.425298472365837

2.42209071247778 0.432235156230854

2.57895632620045 0.460521916809850

2.68559900772363 0.479752237134110

2.70979097605743 0.484114649009811

2.76197414497776 0.493524568561156

2.76341068061933 0.493783611564858

2.85507329914818 0.510312655010629

2.90563229743653 0.519429696315966

2.97068170733797 0.531159718211906

3.03761808247567 0.543230006738578

3.11245164225496 0.556724353514239

3.61120264525975 0.646661528881897

5.47375984678937 0.982526785607316

5.57065841146458 1

with two columns first the element of the set and the second represent the degree of membership of the element

How can i selecet a set from the fuzzy set above which contian the elements have a degree of membership greater than 0.5

with my best regurads

Answer 1

[Arif Hoq]

Try this:

lamda=1;
n=100;m=10;
for i=1:n
    u=rand;
    t(i)=-log(1-u)./lamda;   
end
aa=min(t);aaa=max(t);
alpha=(t-aa)./(aaa-aa);
cut=alpha';
x=t';
fs =sort([x cut]);
element_of_set=fs(:,1);
degree_of_membership=fs(:,2);
greater_value=degree_of_membership(degree_of_membership>0.5) % expexted value greater than 0.5

greater_value = 7×1

0.5102 0.5625 0.6472 0.7921 0.8183 0.8215 1.0000

[Bashar AlHalaq]

thank you for your response

but in need to extract the elements in the fuzzy set that that corespondening to the degree of membership greaterthan 0.5

each elemt and its degree of membership greaterthan 0.5

[Arif Hoq]

is that your answer ? if no, let me do it again.

lamda=1;
n=100;m=10;
for i=1:n
    u=rand;
    t(i)=-log(1-u)./lamda;   
end
aa=min(t);aaa=max(t);
alpha=(t-aa)./(aaa-aa);
cut=alpha';
x=t';
fs =sort([x cut]);
element_of_set=fs(:,1);
degree_of_membership=fs(:,2);
greatr_value_element_of_set=element_of_set(element_of_set>0.5)  % greater value than 0.5 of element of set

greatr_value_element_of_set = 66×1

0.5058 0.5063 0.5217 0.5509 0.5833 0.6188 0.6228 0.6246 0.6251 0.6628

greater_value_degree_of_membership=degree_of_membership(degree_of_membership>0.5) %greater value than 0.5 of degree of membership

greater_value_degree_of_membership = 7×1

0.5025 0.5201 0.5396 0.5577 0.6691 0.9690 1.0000

greater_value_fs=fs(fs>0.5)  % greater value than 0.5 of Fuzzy set

greater_value_fs = 73×1

0.5058 0.5063 0.5217 0.5509 0.5833 0.6188 0.6228 0.6246 0.6251 0.6628

the last variable (greater_value_fs) is shown in 1 single column. first 60 data for 'element of set', rest of 7 for 'degree of membership'. as 'fs' is 2 column matrix you need to arrange it according to your expected outcome.

[Arif Hoq]

Try this one also.

lamda=1;
n=100;m=10;
for i=1:n
    u=rand;
    t(i)=-log(1-u)./lamda;   
end
aa=min(t);aaa=max(t);
alpha=(t-aa)./(aaa-aa);
cut=alpha';
x=t';
fs =sort([x cut]);
element_of_set=fs(:,1);
degree_of_membership=fs(:,2);
greatr_value_element_of_set=element_of_set(element_of_set>0.5);  % greater value than 0.5 of element of set
greater_value_degree_of_membership=degree_of_membership(degree_of_membership>0.5); %greater value than 0.5 of degree of membership
greater_value_from_fs=fs(fs>0.5);  % greater value than 0.5 of Fuzzy set
idx=find(degree_of_membership>0.5);
greater_value_degree_of_membership(idx)=greater_value_degree_of_membership;


%% fuzzy set  in which value of degree of membership >0.5
A=[element_of_set greater_value_degree_of_membership];  %  Make a matrix of fuzzy set 
indices = find(A(:,2)==0);
A(indices,:) = []

A = 18×2

0.0244 0.5388 0.0295 0.5755 0.0456 0.5773 0.0641 0.5791 0.0718 0.5934 0.0938 0.6832 0.1094 0.8300 0.1115 0.9298 0.1146 1.0000 2.7354 0.5388

[Arif Hoq]

fuzzy set:

lamda=1;
n=100;m=10;
for i=1:n
    u=rand;
    t(i)=-log(1-u)./lamda;   
end
aa=min(t);aaa=max(t);
alpha=(t-aa)./(aaa-aa);
cut=alpha';
x=t';
fs =sort([x cut]);
element_of_set=fs(:,1);
degree_of_membership=fs(:,2);
idx=find(degree_of_membership>0.5);
degree_of_membership=degree_of_membership(idx);
element_of_set=element_of_set(idx);
fuzzy_set= [element_of_set degree_of_membership]

fuzzy_set = 12×2

2.2354 0.5318 2.2364 0.5320 2.4019 0.5716 2.4747 0.5890 2.5532 0.6077 2.7268 0.6492 2.8064 0.6682 3.3141 0.7895 3.3858 0.8066 3.4905 0.8317

I am not clear much of your expectation. try anyone of these(mentinoned above).

[Bashar AlHalaq]

thank you that is all right thank you Arif Hoq

[Arif Hoq]

@Bashar AlHalaq If you find your answer, then please consider marking it as accepted answer. That will make it easier for others with similar issues to find an answer.