How to vectorize a matrix?

Dear All,

I have a matrix of 90x12. I need to use 2D look up table for matlab simulink. There i will have to put the vector of input values. That means, Vector for input values x:

[0 1 2 3 4 .........89] and vector for input values 'y': [0 1 2 3 4 5 6 ..11]. How can I write a code that will take the values for x and y automatically with the desired length?

Thanks!

[Fangjun Jiang]

Not clear. Don't understand the question.

Answer 1

[OCDER]

%Starting input
M = reshape(1:90*12, 90, 12); %your 90x12 lookup matrix
X = [0 1 3 4 89]; %input X lookup
Y = [0 1 3 5 11]; %input Y lookup

%Matlab does NOT use 0-based index. So add 1.
X = X+1;
Y = Y+1;

%Use sub2ind to to convert (X,Y) to a linear index. 
Idx = sub2ind(size(M), X, Y);

%Collect your value based on index X and Y
Value = M(Idx); 

In short, the above can be simplified as:

M = reshape(1:90*12, 90, 12); %your 90x12 lookup matrix
X = [0 1 3 4 89]; %input X lookup
Y = [0 1 3 5 11]; %input Y lookup
Value = M(sub2ind(size(M), X+1, Y+1));

[Sky Scrapper]

X = [0 1 3 4 89];

i just need to write this unitil 89 which is not possible.

if I write, A= 1:89 then it gives

A=[1 2 3 4 5 6 7 ...............89]

But now I need to get,

A=[0 1 2 3 4 5 6 7 ..............88]

I think it's very simple, but can't do that.

[Stephan]

A = 0:88;

?

[Sky Scrapper]

If I am writing: A= 0 : size (B,1) %B is my matrix of 89x8

now it's showing: 0,1 ,2 .......................89

But I need: 0,1,2 ............................88

How to do this?

[Stephan]

A = 0:size(B,1)-1 

[Sky Scrapper]

oh i see. i tried: A= 0 : size ((B-1),1)).

I had little bit misunderstanding. thank you very much!