Page 413 - Excel for Scientists and Engineers: Numerical Methods

390 EXCEL: NUMERICAL METHODS

MIdent
Creates an identity matrix of a specified size.

Syntax
MIdent(size)
size optional argument specifying the size of the matrix to be created

Remarks
The function can be used in a formula or used to fill a selection.
When used to fill a selection, the size argument is not required. If selection is not
square, returns #REF! error.
The MIdent function is an array function. To return the array that results when a
range of N rows by N columns is selected, enter =MIdent() and then press
CONTROL+SHIFT+ENTER (Windows) or COMMAND+RETURN or
CONTROL+SHIFT+ RETURN (Macintosh).

Example
The expression MIdent(4) returns { 1,0,0,0;0,1,0,0;0,0,1,0;0,0,0,1).

Arr
Combines individual 1-D arrays into a 2-D array.

Syntax
Arr(range1, range2.. .)
rangel, range2 ... 1 to 29 ranges that you want to combine into a single array

Remarks
The arguments rangel, range2, ... can be either references to ranges of cells or
named ranges.
All individual arrays must be "vertical" and must have same number of rows.
The Arr function is an array function. To return the array that results when
individual ranges with a total combined width of N columns, each with M rows, you
must select a range of cells N columns by M rows, enter the function and then press
CONTROL+SHIFT+ENTER (Windows) or COMMAND+RETURN or
CONTROL+SHIR-+RETURN (Macintosh).

Example
The expression Arr(A4:A13,C4:D13) returns an array three columns wide and ten rows
deep.