How to get this into a loop

Hi there i like to ask how can i get this into a for loop

x=rand(1,20)

h1=(x(2,1)-x(1,1));%First interval

h2=(x(3,1)-x(2,1)); %second interval

h3=(x(4,1)-x(4,1));%Third interval

h4=(x(5,1)-x(4,1));

I like the interval to run for another 20 times

i get it as

for i=1:20

h=( x(1,n) -x(1,(n-1)

iter=iter+1

end

Through this method, i can get 20 iterations but the h is remain the same value, can i know why and how can i change it to get the right way

[Jan]

x  = rand(1, 20)
h1 = x(2,1) - x(1,1); %First interval

This must fail: x has one row only, than x(2,1) does not exist. Please post some working code.

Answer 1

[David Hill]

x=rand(1,20);
for k=1:19
  h(k)=x(k+1)-x(k);
end

Or without loop

x=rand(1,20);
h=diff(x);

[Mark Loui]

Hi thanks so much, i have another question

For example

x=rand(1,20);

for k=1:19

h(k)=x(k);

end

Can this be done?

As from what i seen it keeps getting the same output?

[David Hill]

You do not need a loop to set h=x

x=rand(1,20);
h=x;%h is an array

Answer 2

[Jan]

Why do you want a loop? It is working without a loop also - guessing that you mean x(1, 2) and not x(2, 1) as in the code in the question:

x  = rand(20, 20)
h1 = x(:, 2) - x(:, 1);  % First interval
h2 = x(:, 3) - x(:, 2);  % second interval
h3 = x(:, 4) - x(:, 4);  % Third interval 
h4 = x(:, 5) - x(:, 4);

[Mark Loui]

I like a loop the main question is y=rand(100,1)

I like to generate a for loop

for i=1:n-1
a(k)=y(k) %At each term i get one value extracted from the y
iter=iter+1
end 

The extracted a(k) at different for each term is used later to find something else

[Mark Loui]

Hi there i got it already thanks.

But i have another question, i like to create a diag function with a loop where the matrix is depending on the nxn size, how can i do it ?

After creating the element i like to fill in each of the element with a value, i am having trouble with this matter and not able to get the right approach, please help

[Jan]

What do you want your "diag function with a loop" to do? The explanation " matrix is depending on the nxn size" is not clear enough yet.