sortc, sortcc¶

Purpose¶

Sorts a numeric matrix, character matrix or string array.

Format¶

y = sortc(x, c)¶

y = sortcc(x, c)¶

Parameters

x (NxK matrix or string array.) – data
c (scalar) – specifies the column of x to sort on

Returns

y (NxK matrix) – equal to x and sorted on the column c.

Examples¶

Sort rows of a matrix based upon first column¶

x = { 4 7 3,
      1 3 2,
      3 4 8 };

// Sort 'x' based upon the first row
y = sortc(x, 1);

The above example code produces, y equal to:

3 2
4 8
7 3

Sort rows of a 5x1 string vector¶

// Create a 5x1 string array, using the string
// vertical concatenation operator '$|'
letters = "epsilon" $|
          "gamma" $|
          "beta" $|
          "alpha" $|
          "delta";

// Sort 'letters'
letters_s = sortc(letters, 1);

The above example code produces, letters_s equal to:

  alpha
   beta
  delta
epsilon
  gamma

Remarks¶

These functions will sort the rows of a matrix with respect to a specified column. That is, they will sort the elements of a column and will arrange all rows of the matrix in the same order as the sorted column.
sortc() assumes that the column to sort on is numeric. sortcc() assumes that the column to sort on contains character data.
The matrix may contain both character and numeric data, but the sort column must be all of one type.
Missing values will sort as if their value is below \(-\infty\).
The sort will be in ascending order.
This function uses the Quicksort algorithm.
If you need to obtain the matrix sorted in descending order, you can use:
```
rev(sortc(x, c))
```