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hi friends im new in matlab could you please help me in this problem.

I have an equations A ; A=x*a-b

x=[1 2 5 8 10];

i want to put x values into equation A one by one to solve it, which i mean x1=1, to solve A1 and x2=2 to solve A2 and so on.

after that i want to use the results that i found in this equation B= (A1...An / c).

thanks

Star Strider
on 19 Jan 2020

No loop needed.

If you want to calculate ‘A’ with ‘a’ and ‘b’ already defined numerically as scalars, or if ‘b’ is a vector the same size as ‘x’, just do this:

A = x*a-b

If ‘a’ is a vector with the same dimensions as ‘x’, use element-wise multiplication:

A = x.*a+b

You might need to use bsxfun to do the vector multiplications if you have R2016a or earlier.

Star Strider
on 19 Jan 2020

Then ‘A’ is a (20x5) matrix:

a = rand(20,1);

x=[1 2 5 8 10];

b = rand;

A = a*x - b;

If you have a MATLAB version (release) earlier than R2016b, calculate ‘A’ as:

A = bsxfun(@times, x, a) -b;

to get the same result.

Star Strider
on 21 Jan 2020

The bsxfun function was introduced in R2007a, so you can use it to do the multiplications. I believe the additions always used explicit expansion. If they do not, use bsxfun for those as well:

A = bsxfun(@minus, bsxfun(@times, x, a), b)

That should work.

The loops are all still there, however they are hidden in the bsxfun calls.

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