Note: This section is still being developed under the current version of the software. -Erik 5/24/2008

Examples

Examples taken from the literature demonstrating some of the many capabilities of SISUS.

The links are to pages that include the input workbook and the results produced when submitted to SISUS.

Some of these examples were produced using previous versions of the software. As such, the workbooks differ in format and will experience an error if submitted; instead, copy data from example workbooks to current workbook format.

Getting Started worksheet and results that appear in the current Getting Started guide in the menu.

  • GettingStarted_v0_08
    • Made up data to show some of the capabilities of SISUS, 3 mixtures, one with no solution (n=4, k=2)
    Concentration dependent Mixing Model with linear constraints, Dirichlet prior on simplex, error bars on Convex Hull.

Examples from Phillips' papers in Oecologia, where he and his coauthors developed mixing models for stable isotope sourcing. Papers and software here.

Donald L. Phillips. Oecologia (2001) 127:166--170.
Mixing models in analyses of diet using multiple stable isotopes: a critique
DOI 10.1007/s004420000571
  • P2001Wolf_3-2
    • Phillips in Oecologia (2001), p.167 Table 1 Wolf (n=3, k=2)
    Basic Mixing Model with Unique Solution.

  • P2001Mink_7-2
    • Phillips in Oecologia (2001), p.169 Table 2 Mink (n=7, k=2)
    Basic Mixing Model with Solution Space.
Donald L. Phillips and Jillian W. Gregg. Oecologia (2001) 127:171--179.
Uncertainty in source partitioning using stable isotopes (IsoError)
DOI 10.1007/s004420000578
  • PG2001CaneSoil12yr_2-1
    • Phillips and Gregg in Oecologia (2001) p.174 Table 2 CaneSoil 12yr (n=2, k=1)
    Basic Mixing Model with Unique Solution.

  • PG2001CaneSoil12yrVar_2-1
    • Phillips and Gregg in Oecologia (2001) p.174 Table 2 CaneSoil 12yr with variation (n=2, k=1)
    Basic Mixing Model with Solution Space.
    Solution space results from isotopic variation in mixture and sources. Asking for samples from the isotopic distributions (independent multivariate normals for the mixture and each source) by specifying the number of samples of isotope values using the n.samples.isotope.mvn parameter. Note: The results are skewed a little toward the Sugar cane when variation is allowed. This is because some of the samples from the isotope distributions don't lead to solutions (see process_info.txt "9575 of 10000 = 95.75 % samples lead to feasible solutions"), and the solutions that are not feasible are when Cane soil falls on the far side of Forest soil.
    **Results with variation are experimental.**

  • PG2001CaneSoil50yr_2-1
    • Phillips and Gregg in Oecologia (2001) p.174 Table 2 CaneSoil 50yr (n=2, k=1)
    Basic Mixing Model with Unique Solution.

  • PG2001CaneSoil50yrVar_2-1
    • Phillips and Gregg in Oecologia (2001) p.174 Table 2 CaneSoil 50yr with variation (n=2, k=1)
    Basic Mixing Model with Solution Space.
    Solution space results from isotopic variation in mixture and sources.
    **Results with variation are experimental.**

  • PG2001Wolf_3-2
    • Phillips and Gregg in Oecologia (2001), p.175 Table 3 Wolf (n=3, k=2)
    Basic Mixing Model with Unique Solution.

  • PG2001WolfVar_3-2
    • Phillips and Gregg in Oecologia (2001), p.175 Table 3 Wolf with variation (n=3, k=2)
    Basic Mixing Model with Solution Space.
    Solution space results from isotopic variation in mixture and sources.
    **Results with variation are experimental.**
    ** not confident that population isotopic variation was correctly backed-out from paper **

Donald L. Phillips and Paul L. Koch. Oecologia (2002) 130:114--125.
Incorporating concentration dependence in stable isotope mixing models (IsoConc)
DOI 10.1007/s004420100786 Donald L. Phillips and Jillian W. Gregg. Oecologia (2003) 136:261--269.
Source partitioning using stable isotopes: coping with too many sources (IsoSource)
DOI 10.1007/s00442-003-1218-3



Donald L. Phillips. IsoSource page (2003?).
Additional Constraints

SISUS incorporates linear constraints directly using the "Linear Constraints" worksheet within the input workbook.




I encourage you to send your examples to me to be included here. Please include full reference information.