MUNIT in Collabora Office: Create Identity Matrices and Check Matrix Calculations

• Introduced: original Collabora release and launch date are not established by the sources reviewed.
• Availability: documented in Collabora Office 26.04 help, scoped to the desktop-help release.
• Platform scope: support in every online or mobile deployment is not inferred from desktop documentation.
• Checked: October 14, 2026. Function-specific documentation and independently derived controls; no native Collabora test was performed.

=MUNIT(Dimensions)

The required Dimensions argument gives the square array’s size. This guide uses positive whole-number sizes, as in the official example. Decimal, zero, negative, text or blank dimension conversion is not established here.

The Collabora section calls this a “unitary” array but explicitly defines the identity pattern. In broader mathematics, unitary matrices form a larger class; MUNIT does not generate an arbitrary member of that class.

These examples follow the desktop array-entry workflow documented for Collabora Office 26.04. Select the full output rectangle before entering a multi-cell formula. In the Function Wizard, select Array; for direct entry use the client-appropriate array-entry shortcut shown in the help, Ctrl+Shift+Enter or Command+Shift+Enter. Do not type the displayed outer braces manually.

Input cells and output cells must be separate. The help describes a linked array result whose cells are edited as a group; selecting too small an output rectangle does not redefine the mathematics of the source arrays. This workflow is not a claim that every online or mobile client has the same controls.

Select A2:C4 and enter as an array formula:

=MUNIT(3)

Expected output:

The three diagonal entries are one; all six off-diagonal entries are zero. A useful ordinary aggregate check is =SUM(A2:C4), expected 3. Filling every cell with one would instead total nine and would not create an identity matrix.

The size argument describes both rows and columns. It does not specify the number of nonzero entries independently from the output dimensions.

On a separate sheet, =MUNIT(2) produces rows (1,0) and (0,1) in a two-by-two selected area. Its total is 2. =MUNIT(4) produces a four-by-four identity with four ones and twelve zeros; its total is 4.

Selecting a bigger display rectangle is not the same as changing Dimensions. Use an output selection that exactly matches the requested size so every intended entry is visible without ambiguous extra cells.

Enter a two-by-three matrix with rows (2,0,1) and (1,3,−1) in E2:G3. Retain the three-by-three identity in A2:C4, then select a new two-by-three output range:

=MMULT(E2:G3;A2:C4)

Expected output is unchanged: (2,0,1) and (1,3,−1). The right-hand identity has size three because the input matrix has three columns.

For an identity on the left, use size two, matching the input’s two rows. A two-by-two identity placed on the right would have incompatible inner dimensions. MMULT performs the product; MUNIT only supplies its identity input.

Select another three-by-three area and enter as an array formula:

=5*MUNIT(3)

Expected output has 5,5,5 on the diagonal and zeros elsewhere. Its entry sum is 15. This uses the array overview’s documented elementwise arithmetic with array entry.

If the column vector (2,−1,4) is multiplied by this scaled identity, the expected result is (10,−5,20). It scales each component by five. A three-by-three matrix filled entirely with fives would instead combine components and represents a different transformation.

The three-by-three identity is its own inverse and has determinant 1. With the original output in A2:C4:

=MDETERM(A2:C4)

Expected scalar result: 1. A separately array-entered =MINVERSE(A2:C4) has the same identity output. These give small independent controls for MDETERM and MINVERSE.

For the scaled identity 5I of size three, the determinant is mathematically 125, not 5 or 15. The inverse has diagonal entries 0.2 and off-diagonal zeros. These controls distinguish entry sums, determinants and inverses as separate operations.

MUNIT’s captured section does not document a complete invalid-dimension or maximum-size table. Positive integral sizes two, three and four are the primary examples; exact native error behavior for other inputs is unverified.

The output’s linked-array editing workflow belongs to the cited desktop help. Online/mobile controls and every imported-file conversion require separate testing. These matrices and products were independently calculated, not generated by a native Collabora runtime during this review.

• Collabora Office 26.04: MUNIT and array entry.
• Editorial testing standards.

Complete matrices and outputs were independently calculated using arithmetic and exact rational checks where appropriate. They are documentation-backed expectations, not native Collabora captures or a certification of every type, error and client boundary.