| 1. | Title | Title | VASIP 2: Software Update for Visualizing Propagation of Measurement and Process Errors in VASI Based Site Models |
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| 2. | Creator | Author / affiliation / country | Chris J. Cieszewski; Quantfor Co., Watkinsville, GA, USA; United States |
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| 2. | Creator | Author / affiliation / country | Andrew A. Wawrykowicz; GWN Systems Inc., Edmonton, AB, Canada; Canada |
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| 3. | Subject | Keywords | Variable-age site index; VASI; Base-age invariance; BAI; Self-referencing models; Polymorphic height growth; Measurement error; Process error; Error propagation; Parameter sensitivity |
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| 3. | Subject | Discipline(s) | |
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| 4. | Description | Abstract | This note follows Cieszewski and Wawrykowicz (2025) on VASIP 1.0 and presents VASIP 2, version 2.0.20, for variable-age site index (VASI) curves. The height model is unchanged, and the program retains sixteen historical Alberta and Saskatchewan parameter sets. New functions include: (1) animated graphs with live reference movement; (2) nested conditional bounds at one, two, and three standard errors (SEs); and (3) paired graphs of absolute and relative deviations and bound-sum bias, which measures bound asymmetry about the central curve. Site-index and height-crossing-age readouts update live with the reference point. Adjustable graphs, file imports and exports, named projects, and reporting tools further extend the workflow. Measurement-height variation and global-coefficient variation can be viewed separately or jointly at the selected sensitivity settings. In the program, Process is represented by global-coefficient variation, which changes growth efficiency (the relative height-growth rate). This propagates the coefficient uncertainty represented by the reported SEs, including any effects of lack of fit reflected in them, without simulating stochastic residual disturbances. The program includes a complete user guide; we trace its parameter sources to the 1991 Alberta note and the 1993–1995 Saskatchewan records. The bounds are deterministic sensitivity envelopes informed by marginal coefficient SEs, with no verified probability coverage. |
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| 5. | Publisher | Publisher | Contemporary Journal Concept Press |
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| 6. | Contributor | Contributors / supporting agencies | |
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| 7. | Date | Publication date | 2026-10-30 |
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| 8. | Type | Type | Text.Serial.Journal |
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| 9. | Format | Format | PDF; application/pdf; VASIP-2.0.20-Windows-x64-Setup.exe; application/x-dosexec |
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| 10. | Identifier | Article URL | https://mcfns.com/index.php/Journal/en/article/view/342 |
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| 11. | Source | Journal / volume / issue / year / pages | Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS); Vol. 18 No. 2: MCFNS October 30, 2026; 69-88 (20) |
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| 11. | Source | Online ISSN | 1946-7664 |
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| 12. | Language | Language | en |
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| 13. | Relation | Supplementary files | VASIP-2.0.20-Windows-x64-Setup.exe |
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| 14. | Coverage | Geographical coverage | |
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| 15. | Rights | Rights / copyright | Mathematical and Computational Forestry & Natural-Resource Sciences (MCFNS) 2026 |
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