Vector operatin in Matlab

Hi,

I have to programme a proccess but I don't know how to do it.

I have a vector called 'x' :

X= 1 2 3 4 5 6

On the other hand, another called y (related with x).

Y= 0.1 0. 3 0.4 0.8 0.3 0.5

Then, I have another table that also is from 1 to 6 (the x vector is the same). But this table has only numbers in the 5, 6 and 7th position.

Y1= - - - 0.2323 0.25656 0.8

I need to create one new vector that multiply the y values with the y1 but I don't know how to do it in Matlab.

Greetings and thanks a lot in advance,

[Jan]

The vector does not have a 7th position, because it has 6 elements only.

Please explain this sentence again, what are you needing exactly. "Creating a new vector that multiply y with y1" is not sufficient to understand, what you want to achieve. I cannot imagine, what the "-" in the vector should be.

[klipya]

Thanks Jan for your reply. Yes, you are right, it only has 6 elements, sorry. The '-' element, mean that there aren't any value there. So, for example: I need that the code multiply, on one hand, 6(x)*0.5(y) and, on the other hand, also 6*0.8(y1). And then I need multiply the result of both elements. On the first position I need:

1(x)*0.1(y1) and 1*nothing (becaure there aren't any value, so I need a '0' result).

Why I'm doing this? Because I have one vector called x, one another called y and the last one, y1. And I need that the y1 don't do 1*0.2323 because it's not on the same position (it has to be 1* 0 because there aren't any position).

I don't know if I'm explaining well. I hope yes! Thanks a lot! ;)

Pd) I can't not do it if the size of the vectors are different?

Answer 1

[Andrei Bobrov]

Y= [0.1 0.3 0.4 0.8 0.3 0.5];
Y1 = [0.2323 0.25656 0.8];
out = [zeros(1,numel(Y1)-numel(Y)),Y].*[zeros(1,numel(Y)-numel(Y1)),Y1];

[klipya]

Thanks a lot Venkat and Andrei!

Andrei, I get the next error: "Matrix dimensions must agree." I don't know how to solve it. I understand that it's because of the different structure of the vectors.

[Andrei Bobrov]

My answer was corrected.

[klipya]

Thanks a lot! It works!

[klipya]

Hi Andrei!

Thanks a lot for your message, it helps me a lot! I have tried with my vectors. But I have a lot (more than 2500) and I need to “start” in line 350 but I get this mistake (I also have checked the size and it’s the same):

??? Error using ==> horzcat CAT arguments dimensions are not consistent.

Do you know what can I do? Thanks a lot!

Greetings,

[Andrei Bobrov]

Please give simple numeric example

[klipya]

This is what I've done:

graf=0; for p=(101:180) graf(p)=out1_c; end for p=(171:240) graf(p)=out2_c; end

And I create the document Y1 with O in the places that I don't need and it works.

Answer 2

[venkat vasu]

see these links it will help you

http://www.mathworks.in/help/techdoc/ref/dot.html and http://www.mathworks.in/help/techdoc/ref/cross.html