## Fortran element by element array multiplication

1. The problem statement, all variables and given/known data

Hello,

I'm having a problem in multiplying two vectors together in a specific way in Fortran. I can do it in Matlab, but can't work out how to do it in Fortran.

The problem is that i want to multiply two vectors together, but only each element by it's corresponding element in the other vector. In Matlab you simply use A.*B which works perfectly.

2. Relevant equations

For example if A = [1 2 3]'

and B = [4 5 6]'

Then A.*B = [4 10 18]

3. The attempt at a solution

Any attempt i make in Fortran tries to multiply all the elements together (usually by dot product etc), but i just want the first element multiplied by the first element, and then the second mulitplied by the second etc.

Sorry about the strange formatting, i tried to crowbar this question into the template...
 PhysOrg.com science news on PhysOrg.com >> Ants and carnivorous plants conspire for mutualistic feeding>> Forecast for Titan: Wild weather could be ahead>> Researchers stitch defects into the world's thinnest semiconductor

Mentor
 Quote by Kwetla 1. The problem statement, all variables and given/known data Hello, I'm having a problem in multiplying two vectors together in a specific way in Fortran. I can do it in Matlab, but can't work out how to do it in Fortran. The problem is that i want to multiply two vectors together, but only each element by it's corresponding element in the other vector. In Matlab you simply use A.*B which works perfectly. 2. Relevant equations For example if A = [1 2 3]' and B = [4 5 6]' Then A.*B = [4 10 18] 3. The attempt at a solution Any attempt i make in Fortran tries to multiply all the elements together (usually by dot product etc), but i just want the first element multiplied by the first element, and then the second mulitplied by the second etc. Sorry about the strange formatting, i tried to crowbar this question into the template...
Assuming that all variables and the three arrays are declared and that A and B are initialized, this should work.
Code:
N = 3
DO I = 1, N
C(I) = A(I) * B(I)
END DO
 Ah yes, that would work. Although i'm surprised there isn't a function for it. Thanks a lot though!

## Fortran element by element array multiplication

Vector times vector can also be a scalar, 32.
 Recognitions: Homework Help If you are using at least Fortran 90, I believe the following will work: C = A*B or C(1:N) = A(1:N)*B(1:N) The 1st version assumes A,B,C have the same dimension. The 2nd version is safer.

 Tags arrays, fortran, matlab, multiplication
 Thread Tools

 Similar Threads for: Fortran element by element array multiplication Thread Forum Replies Engineering, Comp Sci, & Technology Homework 4 Electrical Engineering 1 Programming & Comp Sci 5 Math & Science Software 5 Programming & Comp Sci 6