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:

1 3 2
3 4 8
4 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))