SUMX2PY2 in ONLYOFFICE: Add Squares of Two Arrays

ONLYOFFICE’s SUMX2PY2 reference calls this a math-and-trigonometry function and documents:

=SUMX2PY2(array_x, array_y)

Exactly two arguments are documented. The order is array_x, then array_y; swapping the two arrays leaves the mathematical result unchanged. The reference does not specify optional arguments, blank/text coercion, numeric precision or explicit shape-error codes. Example formula notation uses English function names and comma-separated arguments.

Open a blank workbook, use English formula language for these examples, and put the following numeric values in A1:B6. The extra C–E columns below show independently calculated row-level checks; they are not input requirements.

A1: x, B1: y. Enter each row’s A and B numbers exactly as shown (including the negative and decimal values):

For a row-level verification, type =A2^2-B2^2 in C2, =A2^2+B2^2 in D2, and =(A2-B2)^2 in E2. Fill these formulas down through row 6. Compare each cell against the expected row above. Using ordinary numeric cells avoids undocumented text-conversion behavior. The formula result is expected mathematically, not a result observed in ONLYOFFICE.

1. Select a blank result cell G2 outside columns A–E.
2. Enter =SUMX2PY2(A2:A6,B2:B6) using the exact order shown; press Enter (or use the Formula tab’s documented Insert Function dialog).
3. The independent mathematical expectation is 86.5 for these five pairs.
4. For a transparent check, use the applicable C, D or E row-calculation column from the table and sum those five cells. That check uses ordinary operators and the arithmetic results shown; it does not assert a vendor-tested equivalence.
5. Try the partial-range, swapped-array and same-array tests in the table below. Each formula uses two same-shaped input ranges.

Squared vector magnitude. If each x–y pair is a 2D vector, then x² + y² is that observation’s squared length. The row contributions are 5, 25, 4, 50, 2.5, totaling 86.5. The sum is nonnegative for real numeric inputs and is symmetric when the two arrays are swapped.

Advanced: aggregate RMS vector length. =SQRT(SUMX2PY2(A2:A6,B2:B6)/COUNT(A2:A6)) has expected value 4.15932686862. This divides by five observations, not by ten component values; it is the root mean squared 2D vector length. Empty cells and nonnumeric data should be handled before using COUNT as a denominator because no behavior for mixed-type arrays was verified.

Cross-check. The identity Σ(x²+y²) = Σx²+Σy² means =SUMSQ(A2:A6)+SUMSQ(B2:B6) is expected to produce 86.5. Also Σ(x²+y²)−Σ(x−y)² = 2Σxy, which produces 28.5 for the sample. This is independent mathematical validation, not a report of ONLYOFFICE evaluating either expression.

The function’s short official help page documents the required dimensions but does not supply an explicit #VALUE!/#NUM! rule for mismatch or atypical cells. Consequently these are test cases to run in ONLYOFFICE, not observed error claims. If a formula returns a different answer, record the exact Desktop/web build, workbook locale, cell types and screenshot in a future validation pass.

• Documentation evidence, not native execution: The current English function catalogue lists the function and links to the signature described above. The documentation is for ONLYOFFICE Docs Spreadsheet Editor; it is not a function-by-function guarantee for every hosted Docs deployment or Desktop Editors version.
• Desktop versus web: The Docs changelog and Desktop changelog are distinct release histories. Checked 2026-10-13 UTC, neither was used to establish the first-supported version of this function. Do not claim a minimum release number or tested parity without controlled execution on named versions.
• Formula locale: The ONLYOFFICE function-entry guide demonstrates English function names, comma-separated arguments, parentheses, and an initial =. The regional settings guide documents configurable formula language, decimal/thousands separators, and region. These examples use English names, commas between arguments, and a dot for decimals. Recheck the user’s formula language and actual separator settings before copying to a localized workbook; no localized execution was performed.
• Workbook formats: The presence of the formula in the help catalogue does not, by itself, verify Excel, Google Sheets, OpenDocument or earlier-format round trips. Avoid assuming that an identical spelling guarantees identical coercion, error codes or calculation precision elsewhere.

• SUMSQ sums squares of supplied numeric inputs and is useful for independent math cross-checks. It has a distinct argument signature.
• SUMPRODUCT multiplies corresponding values and sums products, useful for the algebraic identities shown above. Its own help page explicitly documents treating nonnumeric entries as zero; that rule must not be transferred to SUMX2PY2 without separate evidence.
• SQRT finds the square root of a number, useful in RMS calculations; negative-input #NUM! belongs to SQRT’s own documented rule, not to SUMX2PY2.
• COUNT counts numeric cells, useful only when observations are paired and complete.

Formula values are independently calculated mathematical expectations. Native ONLYOFFICE Desktop/web execution, localized parsing, undocumented coercion, error propagation and extreme-value precision were not tested.

Official references checked: 2026-10-13 UTC. Native release/edition testing: not performed.