Divide a row vector with a column vector with different dimensions

Question

Mohammad Edaibat 2016-10-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/306189-divide-a-row-vector-with-a-column-vector-with-different-dimensions

评论： Mohammad Edaibat 2016-10-7

I have a problem with dividing a row vector with a column vector both different functions Quickly here is the problem from begining

the equation I want to solve for is EPD = ((H * Lambda) / (Q * GSD)) H = [500:100:1000] Q = [0.2:0.1:2] Lambda and GSD are Constants

What I have done is I created a new vector called HandLambda (Multiplied the constant Lambda with vector H) and Another vector called QandGSD (Mulitplied the constant GSD with the vector Q) then I trasnposed the new vector QandGSD and called it QandGSDreverse (Its now a column vector)

My problem now I'm trying to divide those two new vectors (different dimentions so EPD = ((H * Lambda) / (Q * GSD)) = HandLambda ./ QandGSDreverse

The division is NOT working I thought a row vector can easily be divided with a column vector even with different dimentions

Any thoughts and Ideas?? Also I'm open to change the way this can be solved!

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Adam 2016-10-7

What would you expect the result to be of dividing two vectors of different size? Which elements should divide by what and what happens to the excess elements in either vector?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Massimo Zanetti 2016-10-7

3
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/306189-divide-a-row-vector-with-a-column-vector-with-different-dimensions#answer_237907

编辑：Massimo Zanetti 2016-10-7

在 MATLAB Online 中打开

Better if you use same sized vectors. And use './' instead of '/' to do element wise division.

 %number of points
  n=100;
  %euqally subdivide your variable intervals
  H = linspace(500,1000,n);
  Q = linspace(0.2,2,n);
  %constants
  Lambda=1;
  GSD = 2;
  %equaiton
  EPD = (H * Lambda) ./ (Q * GSD) ;

3 个评论
显示 1更早的评论隐藏 1更早的评论

Massimo Zanetti 2016-10-7

在 MATLAB Online 中打开

Then you have to compute a GRID of values.

H = [500:100:1000]; Q = [0.2:0.1:2] ;
[H,Q]=meshgrid(H,Q);
EPD = (H * Lambda) ./ (Q * GSD) ;

and your result will be a surface

surf(H,Q,EDP);

Mohammad Edaibat 2016-10-7

Massimo,

You saved my life yes the meshgrid worked. So at the end the matrix size HAS to match and this meshgrid just matched them by creating same values repeated

Thanks alot Massimo ;)

请先登录，再进行评论。