IMSUM in Collabora Office: Add Complex Ranges and Verify Both Coordinate Totals
Sum complex ranges in Collabora Calc, audit numeric helper totals and distinguish weighted component sums from totals of magnitudes.
Verification status: See the evidence and test scope described in this guide. How formula examples are checked
Quick answer: IMSUM adds complex values by summing their real and imaginary coefficients. =IMSUM("6+8j";"-3+4j") has independently expected quantity 3+12j.
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 range support
=IMSUM(Complex1 [; Complex2 [; ... [; Complex255]]])
The Collabora section explicitly permits complex values, references to cells and references to cell ranges of complex numbers. The nested optional syntax leaves the first argument required and permits up to 255 arguments.
Complex values use x+yi or x+yj notation. The reference’s explicit control adds 13+4j and 5+3j to obtain 18+7j.
The argument statement is not a complete policy for blanks, mixed ordinary text, Boolean values or errors inside a range. The fixtures below contain only valid complex strings. Keep one consistent suffix; this source does not establish every mixed-suffix outcome.
Example 1: sum a contiguous complex column
Enter exact text 6+8j, -3+4j and 2-5j in A2:A4. Use:
=IMSUM(A2:A4)
Expected quantity: 5+7j. The real total is 6−3+2=5, and the imaginary total is 8+4−5=7.
The explicit scalar-reference version =IMSUM(A2;A3;A4) has the same independently expected quantity. This pair demonstrates the documented range contract without assuming an array-entry procedure that the section does not require.
A one-input call such as =IMSUM("6+8j") retains that quantity under the formal optional-argument syntax. No two-input minimum is inferred from the idea of adding a set.
Example 2: inspect helper totals
In B2 use =IMREAL(A2) and in C2 use =IMAGINARY(A2), filling down. Expected coordinate sequences are 6, −3, 2 and 8, 4, −5.
=SUM(B2:B4) gives 5, and =SUM(C2:C4) gives 7. Compare those numeric totals with the two coefficients extracted from the IMSUM result.
IMREAL and IMAGINARY make the independent check visible. Ordinary SUM is used on numeric helpers, not assumed to apply complex parsing to the original text.
Advanced example: combine a two-dimensional range
In E2:F3, enter this four-cell complex fixture:
| E | F |
|---|---|
| 1+2j | 3-j |
| -2+4j | 5+3j |
=IMSUM(E2:F3) has independently expected quantity 7+8j. All four values contribute; the range is not being interpreted as two pairs to multiply.
Summing each row separately gives 4+j and 3+7j, whose total is again 7+8j. The identity holds for these exact small coefficients; a native calculation involving very different scales may need tolerance-aware checks.
Advanced example: construct a weighted sum explicitly
Apply weights two and three to the first two values in A. Construct their weighted values from numeric coefficients:
=COMPLEX(2*IMREAL(A2);2*IMAGINARY(A2);"j")
=COMPLEX(3*IMREAL(A3);3*IMAGINARY(A3);"j")
Expected quantities are 12+16j and −9+12j. Adding those values gives 3+28j.
This construction avoids assuming that an undocumented plain numeric argument has the same complex-coercion behavior as an explicit complex value. COMPLEX receives its suffix explicitly.
Advanced example: cancellation and recovery
The values 6+8j and 6−8j sum to a quantity with real coefficient 12 and imaginary coefficient 0. Their separate magnitudes sum to twenty, so a magnitude total is a different calculation.
For the primary sum 5+7j, =IMSUB(IMSUM(A2:A4);A4) recovers 3+12j, the sum of the other two values. IMSUB subtracts the selected contribution explicitly.
Input and verification limits
A zero coefficient can be valid cancellation; it is not automatically a missing observation. Keep original records beside the sum when interpreting cancellations.
The 255-argument syntax does not specify every range-size limit, invalid-input error or error precedence. Empty cells, mixed types and native precision boundaries remain unverified here. All shown outputs were independently calculated; no native Collabora execution was performed.
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.