multiplying row vector by a scalar

trying to multiply the third row of a matrix by another row, B:

A = data(3, ;).*B

where B is a row vector

Need help finding a way to multiply the 3rd row of my matrix by a scalar value, for example 100.

Is there a way to do this all in one line?

Thanks!

Answer 1

[VBBV]

 A = data(3, :).*B

[VBBV]

In place of ; you should use :

[Kay]

Hi, yeah sorry that was a typo.

[Kay]

My question still remains: Need help finding a way to multiply the 3rd row of my matrix by a scalar value, for example 100.

[John D'Errico]

@Kay

They both told you how to do EXACTLY that. Did you try it?

[Kay]

Hi. Im sorry. Im a beginner and from my point of view, they didn't answer my question. I probably didn't word it well enough, and thats my fault. I wasn't trying to be rude. This response feels really harsh.

Answer 2

[the cyclist]

You needed a colon in place of that semicolon

A = data(3,:).*B

[Kay]

Hi, yeah sorry that was a typo. My question still remains: Need help finding a way to multiply the 3rd row of my matrix by a scalar value, for example 100.

thanks!

[John D'Errico]

@Kay

They both told you how to do EXACTLY that. Did you try it?

[Kay]

Hi. Im sorry. Im a beginner and from my point of view, they didn't answer my question. I probably didn't word it well enough, and thats my fault. I wasn't trying to be rude. This response feels really harsh.

Answer 3

[John D'Errico]

I think @Kay needs an example.

A = ones(4,3)

A = 4×3

1 1 1 1 1 1 1 1 1 1 1 1

B = 1:3;

A(3,:) = A(3,:).*B

A = 4×3

1 1 1 1 1 1 1 2 3 1 1 1

[Kay]

Hi. Thanks for this. I think I probably didn't word my question well enough, this isn't what I'm looking for. But thanks for your response!

Answer 4

[the cyclist]

% Your matrix
M = magic(4)

M = 4×4

16 2 3 13 5 11 10 8 9 7 6 12 4 14 15 1

% Your scalar
scalar = 100;

% Multiply the third row of your matrix by your scalar
M(3,:) = scalar .* M(3,:)

M = 4×4

16 2 3 13 5 11 10 8 900 700 600 1200 4 14 15 1