MATLAB: How to declare array of variable size

arraycell array

Hi,

I need an array of variable size. for example

for i: 1:63 myArray(i) = zeros(a,b); end

where a,b are changing its value in every loop;

can any one suggest me how to declare that type of array.

for i = 1:63 
  myArray{i} = zeros(a,b); 
end

Do you have the symbolic toolbox? If yes than

syms R G
r = 4/pi * atan((R-G)/(R+G));

else you're more than likely going to hve to define R and G in terms of domains. For example

R = 0:0.01:1;
G = 0:0.1:10; %Make sure the matrix dimensions agree. 
r = 4/pi * atan((R-G)/(R+G));

Matrix manipulation is what matlab was designed to do at its basic level. the symbolic stuff is an add on that works pretty well.

"When preallocating, is it possible to declare types? "

When preallocating you can select any suitable data type, e.g.:

A = zeros(2,3, 'uint8')

Read the zeros, ones, nan documentation to know more.

"Is it worthy in terms of efficiency?"

In most cases preallocation is more efficient than not preallocating.