How can call a vector element using index in the condition of if_else loop?

Here in this code the R is a vector and using find I identified the indexes of specified number and save them to vectors m, n, o, p. Now by using the vector I want to fill the random numbers between 5 and 40 so I developed the following code. But I am not getting desired result.

R=P(:,6);
m =find(R==40);
n =find(R==25);
o =find(R==15);
p =find(R==8)
for k= 1:6160
if k==k.m
    R(k,1)=randi([5 40],:,1);
elseif k==k.n
    R(k,1)=randi([5 40],:,1);
elseif k==k.o
    R(k,1)=randi([5 40],:,1);
elseif k==k.p
    R(k,1)=randi([5 40],:,1);
end
end
R

Answer 1

[SALAH ALRABEEI]

    % Try this
  R=P(:,6);
m =find(R==40);
n =find(R==25);
o =find(R==15);
p =find(R==8)
for k= 1:6160
if ismember(k,m)
    R(k,1)=randi([5 40],1);
elseif ismember(k,n)
    R(k,1)=randi([5 40],1);
elseif ismember(k,n)
    R(k,1)=randi([5 40],1);
elseif ismember(k,n)
    R(k,1)=randi([5 40],1);
end
end
R

[Sharad Patel]

Thank you SALAH but I want only one value of random number between 5 and 40 for each condition.

[Walter Roberson]

So all of the R=40 should result in the same random number for all positions? And all of the 25 should result in the same random number as each other, but different from the R=40?

[Sharad Patel]

it can be 40 as well

Answer 2

[SALAH ALRABEEI]

    % A faster way
R(m,1)=randi([5 40],length(m),1);
R(n,1)=randi([5 40],length(n),1);
R(o,1)=randi([5 40],length(o),1);
R(p,1)=randi([5 40],length(p),1);

[Walter Roberson]

you need

 , 1

on the randi. The default with a single size parameter is square matrix.

[SALAH ALRABEEI]

Absolutely right. Thank you, it will be fix to avoid confusions

Answer 3

[Walter Roberson]

R=P(:,6);
m =find(R==40);
n =find(R==25);
o =find(R==15);
p =find(R==8)
k = [m;n;o;p];
nk = length(k);
R(k,1) = randi([5,40],nk,1);

[Sharad Patel]

Thank you Walter but I want only one value of random number between 5 and 40 for each condition.