Programming

Functions That Control Indexing Style

If you have row-column subscripts but want to use linear indexing instead, you can convert to the latter using the sub2ind function. In the 3-by-3 matrix A used in the previous section, sub2ind changes a standard row-column index of (3,2) to a linear index of 6:

• A = [2 6 9; 4 2 8; 3 5 1];
  
  linearindex = sub2ind(size(A), 3, 2)
  linearindex = 
       6
  

To get the row-column equivalent of a linear index, use the ind2sub function:

• [row col] = ind2sub(size(A), 6)
  row =
       3
  col =
       2
  

Linear Indexing

Accessing Multiple Elements

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