PlanMaker ISFORMULA: Detect formulas replaced by fixed values

The PlanMaker 2026 reference, 2024 reference and 2021 reference were retrieved and compared on October 15, 2026. They document this function’s core operation. Documented by 2021 is not an original introduction date; the first introduction and any last-working-version endpoint remain unverified. The 2026/NX manual family does not establish per-build availability in FreeOffice, mobile clients or every operating system.

The examples below are vendor-supported controls and independently modeled expectations. No native PlanMaker execution, screenshot capture or workbook interchange test was performed. Keep the distinction between documentation support and observed application behavior when applying the guide to an installed version.

=ISFORMULA(Cell)

There is one required argument and no documented optional default. Use a single-cell reference such as A2 for the worked tests. The examples deliberately keep the inspected value in a visible source cell. The formulas use English function names. The one-argument call needs no list separator; nested helper formulas below use commas, which may need adjustment for the installed locale.

SoftMaker explicitly contrasts a formula cell with a fixed number or plain text. Create FormulaOrigins with Entry, Formula_present and Expected_result in A1:C1. Enter the A values below, then fill B2 =ISFORMULA(A2) through B8. Column C in the table is explanatory; type it only as a separate control label if useful.

The result category does not determine formula presence: numbers, text, errors and logical results can all come from formulas. Row 6 may look blank but still contains an expression. A TRUE result says only that a formula is present, not that it is mathematically correct or references the right cells.

In a copy, replace A3 with fixed numeric 25. Its visible value stays 25, but B3 changes to FALSE. That is the central audit case. Conversely, replacing A2 with =25 makes its flag TRUE without making it a useful dependency-driven calculation.

Create LineFormulas with Quantity, Unit_price, Amount and Formula_present in A1:D1. Enter numeric A:B pairs (3,8), (2,15), (5,4), (1,12) in rows 2:5. Fill C2 =A2*B2 through C5, and D2 =ISFORMULA(C2) through D5. Expected amounts are 24,30,20,12 and all D flags are TRUE.

Duplicate the sheet and replace only C3 with the fixed value 30. The displayed amount initially remains correct, but D3 becomes FALSE. Now change B3 from 15 to 16. C3 stays 30, whereas a correct row-based calculation would be 32. The formula-presence audit catches the structural problem before a later source edit reveals the stale result.

On a fresh copy of the original, enter =A2*B2 in C3 instead of the appropriate row-3 formula. D3 still reports TRUE, but C3 is 24, not 30. Thus a formula-presence check needs a separate value or reference audit. A useful independent arithmetic check on these rows is =C2-A2*B2, filled down; it should be zero for the original sheet and becomes -6 for that wrong-row formula.

The PlanMaker help includes a compatibility note saying Excel supports ISFORMULA from Excel 2013 onward. That is an Excel compatibility statement, not a claim that PlanMaker introduced the function in 2013. PlanMaker’s own 2021, 2024 and 2026 references are independently listed below. No import/export test was run.

Point the function at the cell to inspect. Do not replace its reference with a text address or assume a calculation that merely produces the same value has the same formula identity. A literal string beginning with an equals sign is still text if it was imported or entered as text; inspect how the editor stored it.

The short reference does not establish multi-cell range reduction, array spill behavior, external workbook handling or the result of a malformed direct argument. Test those shapes separately. ISREF checks reference validity; ISTEXT checks resulting text; neither substitutes for formula-presence auditing.

Record the PlanMaker version/build, edition, platform, language and workbook format. Recreate the original dataset, inspect the actual formulas and then apply the specified one-cell changes on a copy. Compare the original and changed outputs, not only a screenshot of the final values. Save/reopen and cross-product import results remain separate tests; neither was performed for this guide.