المساعد الشخصي الرقمي

مشاهدة النسخة كاملة : mat2cell function - MATLAB Function Reference



A7med Baraka
03-09-2009, 07:21 PM
mat2cell

Divide matrix into cell array of matrices

Syntax



c = mat2cell(x, m, n)
c = mat2cell(x, d1, d2, d3, ..., dn)
c = mat2cell(x, r)


Description

c = mat2cell(x, m, n) divides the two-dimensional matrix x into adjacent submatrices, each contained in a cell of the returned cell array c. Vectors m and n specify the number of rows and columns, respectively, to be assigned to the submatrices in c.

The example shown below divides a 60-by-50 matrix into six smaller matrices. MATLAB returns the new matrices in a 3-by-2 cell array:


mat2cell(x, [10 20 30], [25 25])


http://matlab.izmiran.ru/help/techdoc/ref/lang_m_a.gif


The sum of the element values in m must equal the total number of rows in x. And the sum of the element values in n must equal the number of columns in x.

The elements of m and n determine the size of each cell in c by satisfying the following formula for i = 1:length(m) and j = 1:length(n):


size(c{i,j}) == [m(i) n(j)]


c = mat2cell(x, d1, d2, d3, ..., dn) divides the multidimensional array x and returns a multidimensional cell array of adjacent submatrices of x. Each of the vector arguments d1 through dn should sum to the respective dimension sizes of x such that, for p = 1:n,


size(x,p) == sum(dp)


The elements of d1 through dn determine the size of each cell in c by satisfying the following formula for ip = 1:length(dp):


size(c{i1,i2,i3,...,in}) == [d1(i1) d2(i2) d3(i3) ... dn(in)]


If x is an empty array, mat2cell returns an empty cell array. This requires that all dn inputs that correspond to the zero dimensions of x be equal to [].

For example,


a = rand(3,0,4);
c = mat2cell(a, [1 2], [], [2 1 1]);


c = mat2cell(x, r) divides an array x by returning a single-column cell array containing full rows of x. The sum of the element values in vector r must equal the number of rows of x.

The elements of r determine the size of each cell in c, subject to the following formula for i = 1:length(r):


size(c{i},1) == r(i)


Remarks

mat2cell supports all array types.

Examples

Divide matrix X into 2-by-3 and 2-by-2 matrices contained in a cell array:


X = [1 2 3 4 5; 6 7 8 9 10; 11 12 13 14 15; 16 17 18 19 20]
X =
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20

C = mat2cell(X, [2 2], [3 2])
C =
[2x3 double] [2x2 double]
[2x3 double] [2x2 double]

C{1,1} C{1,2}
ans = ans =
1 2 3 4 5
6 7 8 9 10

C{2,1} C{2,2}
ans = ans =
11 12 13 14 15
16 17 18 19 20