IMABS Function in ONLYOFFICE Spreadsheet Editor: Complex Magnitudes

Calculate the complex modulus or magnitude |a+bi|, a nonnegative real number sqrt(a²+b²). Its exact current English-reference syntax is =IMABS(inumber). This is documented in the official ONLYOFFICE IMABS function reference, checked 2026-10-13 UTC. Any square brackets in the syntax indicate an optional argument; they are not characters to enter in your formula.

Evidence boundary: Vendor claim checks cover purpose/arguments/current documentation; sample results are separately computed mathematical predictions and were not observed in ONLYOFFICE.

=IMABS(inumber)

Argument rule: One required input; no optional argument or default is documented. Numbers with an imaginary unit should use lowercase i or j as specified by the vendor; direct literal coercion beyond the documented notation is not guaranteed. Do not confuse English argument separators with decimal separators.

In a new worksheet, type the following records. The numbers in B and C must be numeric cells; D contains a lowercase text suffix (i or j). Type the headers into row 1 and the data into rows 2–9. Leave columns E onward empty until entering the formulas. This dataset is original teaching data and does not depend on a downloaded example file.

Select E2 (outside the input table) and enter =COMPLEX(B2,C2,D2). Fill E2 down through E9. This uses the documented three-argument form and lets every later example read the same complex-number cells. If the calculated text contains a simplified zero term, compare the mathematical number rather than presuming a precise string-rendering convention—the official function pages do not specify all serialization cases. Do not paste explanatory table labels into numeric fields.

After creating E2:E9 using the shared input dataset, place =IMABS(E2) in F2 and fill it down. Expected values follow the mathematical modulus rule |a+bi| = sqrt(a²+b²). The official ONLYOFFICE IMABS article establishes complex absolute value as the function purpose; this identity and the numbers below were independently calculated.

Reproduce and validate: In G2 enter =SQRT(IMREAL(E2)^2+IMAGINARY(E2)^2) and copy down. Mathematically F and G should be equal for ordinary finite inputs. The supplementary formula is justified by the independently derived modulus identity and the official descriptions of SQRT, IMREAL and IMAGINARY. SQRT is not a substitute for confirming ONLYOFFICE’s complex-string parsing; both expressions remain native-test items.

Numeric controls

=IMABS(COMPLEX(5,12,"i"))
=IMABS(COMPLEX(-6,8,"j"))
=IMABS(COMPLEX(0,-7,"i"))

Their independently calculated expected numeric results are 13, 10, and 7, respectively. This verifies that magnitude ignores the sign of each squared component but does not claim that invalid inputs will be silently converted.

Suppose every sample in B/C is a pair of orthogonal components measured in the same units. In H2 enter =IF(IMABS(E2)>10,"Review","OK") and fill through H3. For E2=3+4i, the predicted label is OK, because the magnitude is 5. For E3=−5+12i, the predicted label is Review, because magnitude 13 exceeds 10. The vendor documents IF conditional semantics; the sample comparison results follow independent arithmetic.

Interpretation caution: Complex modulus is a magnitude in the units of the underlying components. It is neither the real part nor the imaginary coefficient, and it is not an automatically calculated power or energy. If you require squared magnitude for power-related work, multiply IMABS(E2)^2 deliberately and document any physical assumptions.

1. Malformed input: the official inumber argument is a complex number in x+yi or x+yj notation. A free-form text label such as "sensor" is not a valid documented input; the article does not publish an exhaustive mapping to specific error codes.
2. Missing argument: IMABS has one required value and no optional defaults.
3. Wrong operator: adding absolute real and imaginary parts (ABS(a)+ABS(b)) is not the same as modulus except in special cases. For 3+4i it gives 7 instead of 5.
4. Negative components: the modulus is nonnegative. =IMABS(COMPLEX(-3,-4)) has mathematical expectation 5, not −5.
5. Text/locale issues: after importing files, verify that E2 contains a valid formula-produced complex number rather than text with an unexpected separator. The vendor’s high-level function page does not establish conversion of every string variant.
6. Very large components: floating-point precision, rounding and overflow depend on the runtime and build; no undocumented numerical threshold is asserted here. Compare known small cases first.

If the formula fails, start with =IMABS(COMPLEX(3,4)); then inspect the source real/imaginary columns; then check the F versus G arithmetic; finally record the installed Docs/desktop version. Do not describe mathematical validation as a passing editor test.

In the current ONLYOFFICE Spreadsheet Editor Help Center, these functions appear in the Engineering group. To locate them, use Formula → More functions → Engineering, or the Insert Function dialog and search for the exact English name. You can also type formulas directly, starting with =. This navigation and keyboard entry method are documented by the official Insert Functions guide (checked 2026-10-13).

All formulas here use the official English names and comma-delimited syntax. The ONLYOFFICE Advanced Settings reference explains that formula language and regional settings can vary. If your editor displays a translated function name or expects another list separator, use its formula assistant rather than blindly substituting punctuation. Decimal commas and argument separators are separate regional concerns. In example formulas, literal complex numbers and the suffix are text in double quotes; unquoted entries such as 3+4i are not equivalent to a quoted text literal.

Edition and version applicability

The current unversioned ONLYOFFICE Docs Help Center documents this function. That verifies present official documentation, not a first-supported version, successful execution in every deployed Docs server, or equivalent outcomes in all versions of Desktop Editors. The ONLYOFFICE Docs changelog and Desktop Editors changelog were consulted on 2026-10-13; neither was used to infer an undocumented first introduction release for this function. Native tests on identified Docs/web and Desktop versions are still required, especially for edge-case parsing, exact error text, and round-trip formatting. Excel, Google Sheets, other spreadsheet products and cmath are not evidence of ONLYOFFICE’s native behaviour.

Verification: Argument definitions and purposes come from the linked official references. Expected values were independently calculated. Native ONLYOFFICE Docs web or Desktop execution, historical-edition testing, localized syntax, exact errors and output formatting were not tested.

• ONLYOFFICE IMABS function: primary syntax and purpose.
• ONLYOFFICE Insert Functions: engineering category and how to enter formulas.
• ONLYOFFICE Spreadsheet Editor Advanced Settings: formula language and region.
• ONLYOFFICE Docs changelog: product release history, not proof of this function’s introduction.
• ONLYOFFICE Desktop Editors changelog: independent desktop release history.
• Related official references: COMPLEX, IMREAL, IMAGINARY, IMARGUMENT.