How do I create a vector of n exponentially increasing values from a to b?

I know how to calculate the growth factor, but not how to turn it all into a vector. Here's the start of my code: -

 n = 4
a = 1
b = 10
gf = (b/a)^(1/n - 1)

[Tom]

I think I've done it with a for loop: -

 n = 4
a = 1
b = 10
gf = (b/a)^(1/(n - 1))
for k = 1:n
y(k) = a*gf^(k-1);
end

Does anyone know how I could do it using a non-for loop method?

Answer 1

[the cyclist]

k = 1:n;
y = a*gf.^(k-1);

or, even simpler

y = a*gf.^((1:n)-1);

[Tom]

Great thanks

[Ramm]

Is this a specific module that I need to add? In my case it doesn't work:

n = 4;
a = 1;
b = 10;
K>> 
K>> k = 1:n;
K>> y = a*gf.^(k-1);
Error using  .^  (line 1000)
Sizes of x, y don't match.

K>> y = a*gf.^((1:n)-1);
Error using  .^  (line 1000)
Sizes of x, y don't match.

[Stephen23]

@Ramm: That error message is telling you what the problem is. It does not mention that you need any "specific module". It shows that your gf is non-scalar and is not the same size as k, thus you will get this error. The code in this answer works perfectly, as long as you define a scalar growth factor (exactly as the question shows):

>> n = 4;
>> a = 1;
>> b = 10;
>> gf = (b/a)^(1/n-1)
gf =  0.17783
>> k = 1:n;
>> y = a*gf.^(k-1)
y =
   1.0000000   0.1778279   0.0316228   0.0056234

Answer 2

[Carlos]

>> y=zeros(4,1);
>> n=1:1:4;
>> y(1:4)= a*gf.^(n(1:4)-1);
>> y

y =

      1.0000
      2.1544
      4.6416
     10.0000

[Tom]

Many thanks

[Ramm]

This doesn't work either.

[Stephen23]

@Ramm: although that n usage is a bit dodgy, it also works.