IMPRODUCT in Collabora Office: Multiply Complex Ranges and Verify Cross-Terms
Multiply complex values and ranges in Collabora Calc, audit real and imaginary cross-terms and keep explicit complex factors separate from plain numeric coercion.
Verification status: See the evidence and test scope described in this guide. How formula examples are checked
Quick answer: IMPRODUCT multiplies complex values. =IMPRODUCT("6+8j";"2-j") has independently expected quantity 20+10j, including both real and imaginary cross-terms.
Availability and version history
- Introduced: the original Collabora release and launch date are not established by the reviewed sources.
- Availability: documented in Collabora Office 26.04 desktop help.
- Platform scope: online and mobile deployment support is not inferred from the desktop documentation.
- Checked: October 14, 2026. Function-specific documentation and independent controls; no native Collabora execution.
Syntax and documented range inputs
=IMPRODUCT(Complex1 [; Complex2 [; ... [; Complex255]]])
Collabora explicitly allows complex values, cell references and cell ranges of complex numbers. The first argument is required; the nested optional syntax extends to 255 arguments.
The reference’s direct control multiplies 3+4j by 5−3j to obtain 27+11j. For a+bj times c+dj, the real coefficient is ac−bd and the imaginary coefficient is ad+bc.
The minus sign follows from j²=−1. Multiplying corresponding coefficients independently would be a different operation. These examples use explicit complex inputs rather than assuming a plain numeric scalar’s coercion rule.
Example 1: multiply paired records
Enter only the first two text columns in A1:B5. In C2 use =IMPRODUCT(A2;B2) and fill down. Expected quantities occupy the last column.
| A, first factor | B, second factor | C, product |
|---|---|---|
| 6+8j | 2-j | 20+10j |
| 3+2j | 1-4j | 11-10j |
| -2+3j | 4+j | -11+10j |
| 1+j | 1-j | 2 |
For the second row, the real coefficient is 3×1−2×(−4)=11; the imaginary coefficient is 3×(−4)+2×1=−10.
The last product has real coefficient two and imaginary coefficient zero. Its simple written quantity does not certify the native result’s storage TYPE.
Example 2: expose a sign error with numeric helpers
For the first pair, extract coefficients a=6, b=8, c=2 and d=−1 using IMREAL and IMAGINARY.
The numeric checks are =6*2-8*(-1), giving 20, and =6*(-1)+8*2, giving 10. Constructing =COMPLEX(20;10;"j") reproduces the product quantity.
Using ac+bd instead would give 4 for the real coefficient. That plausible-looking number exposes why the cross-term sign must be checked.
Advanced example: multiply a contiguous range
Enter exact text 1+j, 2-j and 3+2j in E2:E4. Use:
=IMPRODUCT(E2:E4)
Expected quantity: 7+9j. The first two factors give 3+j; multiplying by 3+2j gives real coefficient 9−2=7 and imaginary coefficient 6+3=9.
The scalar-reference version =IMPRODUCT(E2;E3;E4) has the same independently expected quantity. Range support is explicit in this product’s source; no blank or mixed-type aggregation policy is inferred from it.
A single-input call retains the input quantity under the formal syntax. It does not square that input automatically.
Advanced example: explicit real scaling and rotation
To double 6+8j without relying on undocumented numeric coercion, use the explicit complex factor 2+0j. =IMPRODUCT("6+8j";"2+0j") has expected quantity 12+16j.
Multiplying by 0+1j instead produces −8+6j. Repeating the quarter-turn gives −6−8j, then 8−6j, then the original 6+8j. Every state has magnitude ten.
COMPLEX can build those explicit factors from numeric coefficients with a supplied “j” suffix.
Advanced example: conjugates and inverse recovery
Multiplying 6+8j by its conjugate 6−8j yields real coefficient 100 and imaginary coefficient 0. IMCONJUGATE provides that sign reversal.
For the first paired product, =IMDIV(C2;B2) recovers 6+8j, since B2 is nonzero. IMDIV reverses the multiplication under its own numerator/denominator contract.
The product magnitude is the square root of 500, approximately 22.360679775. It equals ten times the square root of five mathematically, offering another independent check.
Input and numeric limits
All range cells here contain valid, consistently suffixed complex text. The 255-argument statement does not specify every range-size, blank, ordinary-text or error policy.
Native malformed-input errors, mixed-suffix handling, zero coercion and extreme overflow remain unverified. Component calculations and moderate exact fixtures are the verification scope, not a promise of identical last digits under every evaluation order.
References and verification
Complete function-specific documentation reviewed. Outputs are independent complex-component models or explicit documented controls, not captured native application results. Formulas use English names and semicolon separators; optional-argument brackets describe syntax and are not typed into working formulas.