inserting index for variable

Hi everyone!

I want make index for my variable. I write a simple code:

x=8;
b=9;
for i=1:2
    w(i)=x+b
    u=x+w(i)
end

I expect something like this:

w(1)=17

u(1)=8

w(2)=17

u(2)=25

but code doesnt do this.

Since I've just started programming with MATLAB. Im not familiar with this syntax.

I appreciate any help.

[Riccardo Scorretti]

Dear Shirin,

in your code, the variable u is not a vector. Try this:

x=8;
b=9;
for i=1:2
    w(i)=x+b
    u(i)=x+w(i)
end

w = 17

u = 25

w = 1×2

17 17

u = 25

However, notice that in this way your vector will be increasing; this is a bad practice from the point of view of computational efficiency.

Most importantly, there is strictly no reason for you to obtain the result you posted beause w(i) = x+b = 17 for any index i, hence u(i) = x+w(i) = 2x+b = 25 is constant as well (no matter if u is a vector or a scalar). Are you sure of your algorithm?

Answer 1

[Torsten]

I don't know what you mean by "I want make index for my variable", but

x = 8;
b = 9;
w = zeros(2,1);
u = zeros(2,1);
for i = 1:2
    u(i) = x + w(i);
    w(i) = x + b;
end

at least reproduces your expected output.