How to specify size of row and column vector

    *If we have a row vector A
    and a column vector B

    How do we specify the size for both vectors ?*

Answer 1

[Wayne King]

sizeofvector = input('What size vector do you want? Enter the size in brackets, e.g. [100 1]\n');
 %%%user enters [1 1000]
 x = 10+10*rand(sizeofvector(1),sizeofvector(2));

[Mohamad]

Awesome this is what I was looking for. One question. How do you explain this "10+10*rand" . what if i want the numbers to be between 10 and 100 ?

Thanks

[Image Analyst]

If you look up rand, you'll see this in the help:

Example 1
 Generate values from the uniform distribution on the interval [a,b]:
 r = a + (b-a).*rand(100,1);

I assume you know that a=10 and b=100 and can figure everything else.

Answer 2

[Wayne King]

How do you find the size, or how do you specify?

To find the size, simply use length()

 A = randn(100,1); 
 length(A)

If you want to pre-allocate, then you can use zeros()

 A = zeros(100,1);

If this is not answering your question, can you please elaborate and give an example.

[Mohamad]

Not really what I was looking for but still helpful.

My question was let us say u want to prompt a user to specify the size of a row vector and a column vector, that has random numbers between 10 and 20. how do u create that row vector and column vector, that has been specified with a size

Answer 3

[Image Analyst]

Try this:

% Ask user for a number.
defaultValue = {'7'; '5'};
titleBar = 'Enter a value';
userPrompt = {'Enter the row vector width '; 'Enter the column vector height '};
caUserInput = inputdlg(userPrompt, titleBar, 2, defaultValue);
if isempty(caUserInput),return,end; % Bail out if they clicked Cancel.
rowWidth = str2double(caUserInput{1})
columnHeight = str2double(caUserInput{2})

% Make the row vector and column vector with some arbitrary values.
rowVector = zeros(1, rowWidth)
columnVector = ones(columnHeight, 1)