YIELDMAT Function (OpenOffice Calc)

• Introduced: First release not established; documented by OpenOffice.org 3.3.
• Supported in: Apache OpenOffice 4.1.16; this is a verified release, not a final supported version.
• Scope: Desktop Calc, English function names and semicolon-separated formulas.
• Checked: October 14, 2026. Eight ordinary reference formulas were recalculated from generated ODF in 4.1.16 on Linux x86-64, Build 9816. Source and independent arithmetic were checked.

YIELDMAT calculates the yield for interest paid at maturity from a quoted price per 100 and three date fractions. Its settlement-value denominator includes accrued interest. It is not the regular coupon YIELD solver and does not use a coupon-frequency argument. Release implementation.

YIELDMAT(Settlement;Maturity;Issue;Rate;Price[;Basis])

• Settlement, Maturity, Issue: dates; use Issue≤Settlement<Maturity.
• Rate: positive annual interest rate in this implementation.
• Price: positive quoted price per 100 for the ordinary model.
• Basis: optional 0, with alternatives 1–4. The returned rate is annualized under those fractions.

The native column contains saved 4.1.16 results; independent references use high-precision arithmetic and the stated source rules. Values are shown to twelve decimal places where needed. Enter DATE expressions directly rather than locale-dependent date text.

For issue January 1, settlement July 1, 2024, maturity January 1, 2025, rate 5%, price 99 and basis 0, the maturity payment is 105 per 100. Settlement value includes 2.5 accrued interest, so its denominator is 99+2.5=101.5.

The yield is (105/101.5-1)/0.5≈0.068965517241, or 6.8965517241%. Dividing 105 by 99 without the accrued part would describe a different calculation. At settlement equal to issue, the accrued fraction is zero and the native one-year result is approximately 0.060606060606.

With A=year fraction Issue→Maturity, B=Issue→Settlement and C=Settlement→Maturity, the helper computes ((1+A*Rate)/(Price/100+B*Rate)-1)/C. PRICEMAT reverses this algebra when the same dates, rate and basis are supplied.

For the January–July–January example, basis 1 gives approximately 0.068867697047, basis 2 gives 0.068518408374, and basis 3 gives 0.068809526604. The rate difference comes from the helper fractions rather than a different market price. The April–October basis-0 example in the table returns exactly 6% to the shown precision.

The wrapper rejects Rate≤0 and Settlement≥Maturity. It does not provide every useful model check, so validate positive Price, Issue≤Settlement and a positive accrued settlement denominator yourself. All native cases use ordinary valid dates and positive rate/price; invalid domains and nonpositive prices were not executed.

The result assumes the stated interest is paid at maturity and the price convention matches the formula. It does not infer periodic coupon dates, transaction costs or suitability of a quoted yield. Keep the accrued portion separate when auditing the denominator and when comparing with YIELDDISC or the periodic-coupon YIELD function.

PRICEMAT, YIELDDISC, YIELD.

• Function-specific release implementation
• Function calculation helper
• GetYearFrac date-fraction helper
• GetDiffParam date-fraction helper

The generated ODF produced the informational load warning “Not all attributes could be read.” The sheet was hard-recalculated and saved separately. All eight ordinary function identities, inputs and results were reconciled; a stale SUM cache changed from 999999 to 3 and an uncached SUM returned 7. This establishes the stated examples, not every workbook style or invalid input. Other explanatory identities are independent calculations. The authoring-tool XLSX was not executed in OpenOffice, and its preview values are not the native results reported here.