How do i code this variable in Matlab

i have 2 matrix which have have same size.. if 1st matrix is size 5 the 2nd will also will be 5 if the 1st matrix is size 10 the 2nd will be 10

for example

   %1st matrix
    DF = [NaN 4 6 ;
          3 NaN 5 ;
          5 4 NaN ] ;  

   %2nd matrix
    W = [6  10  5 ;
         9   7  3 ;
         1   4  8 ];  
% PROBLEM SIZE (NUMBER OF SITES OR DEPTS)
    pr_size = size(DF,1);

how do i code matrix W as pr_size? because W will be follow DF size?

Answer 1

[Walter Roberson]

You can initialize with

W = zeros(size(DF));

or with

 W = 0 * DF;

[sharifah shuthairah syed abdullah]

can i do it like this pr_size = size (DF, W) ? is it tell the same thing? because the pr_size i will be using for another thing at another part of the code

[Walter Roberson]

No, but you can code

W = zeros(pr_size, size(DF,2))

[sharifah shuthairah syed abdullah]

may i know, what is "zeros" mean ?

[sharifah shuthairah syed abdullah]

if i put the code like this

% PROBLEM SIZE (NUMBER OF SITES OR DEPTS)

W = zeros(pr_size, size(DF,2))

the will be an error said that "Undefined function or variable 'pr_size'."

[Walter Roberson]

zeros() is allocates an array of the given size, all filled with the value 0.

There is also a function ones() that allocates a matrix of the given size, all filled with the value 1.

You can also use size arguments for nan() and for inf() and for true() and false()

[sharifah shuthairah syed abdullah]

thank you so much for the info..

if i put the code like this

% PROBLEM SIZE (NUMBER OF SITES OR DEPTS)

W = zeros(pr_size, size(DF,2))

the will be an error said that "Undefined function or variable 'pr_size'."

if i put it like this

% PROBLEM SIZE (NUMBER OF SITES OR DEPTS)

pr_size = size(DF,1);

W = ones(pr_size, size(DF,2));

will matlab rewrite one of them?

[Walter Roberson]

You need to define pr_size before you can use it.

I do not understand what you mean about writing one of them?

Is it possible that you already have D and already have W, and the task is to check to see whether they do have the same size or not?

[sharifah shuthairah syed abdullah]

i already have DF and W matrix, they are the same, i want to add matrix DF with W,

[Walter Roberson]

DF + W