IMEXP Function (LibreOffice Calc)

IMEXP returns the exponential of a complex number. It calculates e raised to a+bi, with e ≈ 2.71828. Unlike the ordinary numeric EXP function, IMEXP accepts complex input such as "1+i" and returns the result in complex-number text format. LibreOffice’s Engineering/Add-in function reference documents the signature and example; the real and imaginary pieces follow e^(a+bi) = e^a × (cos(b) + i sin(b)). The original short guide described this as the algebraic form of a complex exponential.

Copy-and-try:

=IMEXP("1+i")

Expected mathematically and observed in native Calc 25.2.3.2: 1.46869393991589+2.28735528717884i.

=IMEXP(ComplexNumber)

ComplexNumber — Required. One complex number expressed as text ("1+i", "3-4j"), a cell reference such as A2, the output of COMPLEX(RealNum;INum), or a real-only number such as 2.

The argument represents the complex exponent. i and j are supported imaginary-unit suffixes; follow the spelling used by your source data. There is no second optional argument or default exponent. English-language Calc Help uses semicolon separators inside multiargument expressions such as COMPLEX(3;4); formula delimiters, decimal separators, and localized function names can vary by configuration. Plain quoted complex literals use a period as decimal separator in the examples below. The official Help shown on 2026-10-11 carried a LibreOffice 26.8 Help banner; execution below used LibreOffice Calc 25.2.3.2. That observation does not establish an earliest supported version or another platform’s behaviour.

Enter the following values into an empty Calc sheet. For A2, enter 1+i as text (no leading equals sign); B2 and C2 are numeric coefficients.

On a narrow screen, scroll this table sideways to see every column.

In D2 enter:

=IMEXP(A2)

Expected / native observed: 1.46869393991589+2.28735528717884i. The result’s real part is e × cos(1), and the imaginary part is e × sin(1).

For a real-only exponent:

=IMEXP(2)

Expected / observed: 7.38905609893065 as text. The returned text is important: to perform normal numerical arithmetic on a real-valued result, extract it using IMREAL or use EXP(2) instead.

Combine your numeric columns rather than manually assembling strings:

=IMEXP(COMPLEX(B2;C2))

Expected / observed: -13.1287830814622-15.200784463068i for 3+4i. The COMPLEX function constructs the complex string from two coefficients.

A useful nonzero-input consistency check is:

=IMEXP(IMLN("3+4i"))

Expected / observed: 3+4i. IMLN chooses a complex logarithm and IMEXP reverses it (up to rounding). This does not mean the reverse composition IMLN(IMEXP(z)) always recovers every input without branch changes; avoid assuming equality for arbitrary imaginary components.

Changing the imaginary-unit suffix is supported:

=IMEXP("1+j")

Expected / observed: 1.46869393991589+2.28735528717884j.

• Err:502: In native Calc 25.2.3.2, =IMEXP("wrong") and =IMEXP("1+2k") both returned Err:502 (error code 502). Check malformed complex literals, text entered with an unsupported suffix, and locale-specific decimal input.
• Looks numeric but doesn’t sum normally: =ISTEXT(IMEXP(1)) evaluated to TRUE. Use IMREAL(IMEXP(2)) to obtain a numeric real coefficient, or EXP(2) if all your values are real and you need a number.
• Unexpected sign: The imaginary part can be negative even when a real component is positive. It follows the trigonometric sine of the imaginary coefficient. Check the sign entered in A2 before assuming the calculation is wrong.
• Rounded display: The full complex string may contain many digits. Treat nearly equal floating results using a tolerance rather than exact string equality.
• i versus j: Preserve one convention across imported rows to avoid inconsistent-looking output. Both suffixes were natively tested with this function.

Microsoft Excel IMEXP also takes one complex-number argument and documents x+yi/x+yj text input. In Excel’s standard English syntax you normally see IMEXP(inumber); don’t paste semicolon-separated nested Calc formulas without checking destination locale. Excel was documentation-checked, not executed. ODF storage, mobile/web implementations, and numerical formatting across spreadsheet engines were not tested.

COMPLEX · IMLN · IMPOWER · IMREAL · EXP · IMABS

1. LibreOffice 26.8 Help — IMEXP in Add-in Analysis Functions, accessed 2026-10-11. Supports the exact one-argument signature, complex text notation, function purpose and the rounded 1+j example.
2. LibreOffice Help — analysis function index, accessed 2026-10-11. Establishes the documented function family; the latest Help banner is not a promise of support in every installed edition.
3. Microsoft Excel IMEXP support, accessed 2026-10-11; compatibility claim only.
4. Original general Calc Help link, preserved from the existing page’s front matter.

Selected example formulas were run in LibreOffice Calc 25.2.3.2 on Linux on October 12, 2026. The official Help may cover a newer version. Tests of selected formulas do not certify every locale, interactive array operation or file round trip. View the example-check record.

Official IMEXP reference · Editorial standards