Cell Indexing with Smooth Parentheses, ()

Cell array indices in smooth parentheses refer to sets of cells. For example, to create a 2-by-2 cell array that is a subset of C, use smooth parentheses.

upperLeft = C(1:2,1:2)

upperLeft=2×2 cell array
    {'one'}    {'two'}
    {[  1]}    {[  2]}

Update sets of cells by replacing them with the same number of cells. For example, replace cells in the first row of C with an equivalent-sized (1-by-3) cell array.

C(1,1:3) = {'first','second','third'}

C=2×3 cell array
    {'first'}    {'second'}    {'third'}
    {[    1]}    {[     2]}    {[    3]}

If cells in your array contain numeric data, you can convert the cells to a numeric array using the cell2mat function.

numericCells = C(2,1:3)

numericCells=1×3 cell array
    {[1]}    {[2]}    {[3]}

numericVector = cell2mat(numericCells)

numericVector = 1×3

     1     2     3

numericCells is a 1-by-3 cell array, but numericVector is a 1-by-3 array of type double.

Content Indexing with Curly Braces, {}

Access the contents of cells--the numbers, text, or other data within the cells--by indexing with curly braces. For example, to access the contents of the last cell of C, use curly braces.

last = C{2,3}

last = 3

last is a numeric variable of type double, because the cell contains a double value.

Similarly, you can index with curly braces to replace the contents of a cell.

C{2,3} = 300

C=2×3 cell array
    {'first'}    {'second'}    {'third'}
    {[    1]}    {[     2]}    {[  300]}

You can access the contents of multiple cells by indexing with curly braces. MATLAB® returns the contents of the cells as a comma-separated list. Because each cell can contain a different type of data, you cannot assign this list to a single variable. However, you can assign the list to the same number of variables as cells. MATLAB® assigns to the variables in column order.

Assign contents of four cells of C to four variables.

[r1c1, r2c1, r1c2, r2c2] = C{1:2,1:2}

r1c1 = 
'first'

r2c1 = 1

r1c2 = 
'second'

r2c2 = 2

If each cell contains the same type of data, you can create a single variable by applying the array concatenation operator, [], to the comma-separated list.

Concatenate the contents of the second row into a numeric array.

nums = [C{2,:}]

nums = 1×3

     1     2   300