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author | Johannes Ranke <jranke@uni-bremen.de> | 2020-05-13 16:20:23 +0200 |
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committer | Johannes Ranke <jranke@uni-bremen.de> | 2020-05-13 16:20:23 +0200 |
commit | 218a9c55bd80fb708b15fa7196422f759bfe4b27 (patch) | |
tree | ad4b2aa4b561b3118d1ca8ee5e6b34fbd2dfcfe8 /vignettes/web_only/NAFTA_examples.Rmd | |
parent | 36bc31c52cbe4b686f5562e21ee110380481dff8 (diff) |
Further formatting improvement of benchmark vignette
Also, use .rmd extension instead of .Rmd for vignettes.
Diffstat (limited to 'vignettes/web_only/NAFTA_examples.Rmd')
-rw-r--r-- | vignettes/web_only/NAFTA_examples.Rmd | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/vignettes/web_only/NAFTA_examples.Rmd b/vignettes/web_only/NAFTA_examples.Rmd deleted file mode 100644 index 26a9240a..00000000 --- a/vignettes/web_only/NAFTA_examples.Rmd +++ /dev/null @@ -1,243 +0,0 @@ ---- -title: "Evaluation of example datasets from Attachment 1 to the US EPA SOP for the NAFTA guidance" -author: "Johannes Ranke" -date: "`r Sys.Date()`" -output: - html_document: - toc: true - toc_float: - collapsed: false - mathjax: null - fig_retina: null -references: -- id: usepa2015 - title: Standard Operating Procedure for Using the NAFTA - Guidance to Calculate Representative Half-life Values and Characterizing - Pesticide Degradation - author: - - family: US EPA - type: report - issued: - year: 2015 - url: https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/standard-operating-procedure-using-nafta-guidance -vignette: > - %\VignetteIndexEntry{Example evaluation of FOCUS Laboratory Data L1 to L3} - %\VignetteEngine{knitr::rmarkdown} - %\VignetteEncoding{UTF-8} ---- - -# Introduction - -In this document, the example evaluations provided in Attachment 1 to the SOP -of US EPA for using the NAFTA guidance [@usepa2015] are repeated using mkin. -The original evaluations reported in the attachment were performed using PestDF -in version 0.8.4. Note that PestDF 0.8.13 is the version distributed at the US -EPA website today (2019-02-26). - -The datasets are now distributed with the mkin package. - -```{r, include = FALSE} -library(knitr) -opts_chunk$set(tidy = FALSE, cache = FALSE, fig.height = 7) -library("mkin", quietly = TRUE) -``` - -# Examples where DFOP did not converge with PestDF 0.8.4 - -In attachment 1, it is reported that the DFOP model does not converge for these -datasets when PestDF 0.8.4 was used. For all four datasets, the DFOP model can -be fitted with mkin (see below). The negative half-life given by PestDF 0.8.4 -for these fits appears to be the result of a bug. The results for the other -two models (SFO and IORE) are the same. - -## Example on page 5, upper panel - -```{r p5a} -p5a <- nafta(NAFTA_SOP_Attachment[["p5a"]]) -plot(p5a) -print(p5a) -``` - -## Example on page 5, lower panel - -```{r p5b} -p5b <- nafta(NAFTA_SOP_Attachment[["p5b"]]) -plot(p5b) -print(p5b) -``` - -## Example on page 6 - -```{r p6} -p6 <- nafta(NAFTA_SOP_Attachment[["p6"]]) -plot(p6) -print(p6) -``` - -## Example on page 7 - -```{r p7} -p7 <- nafta(NAFTA_SOP_Attachment[["p7"]]) -plot(p7) -print(p7) -``` - -# Examples where the representative half-life deviates from the observed DT50 - -## Example on page 8 - -For this dataset, the IORE fit does not converge when the default starting values -used by mkin for the IORE model are used. Therefore, a lower value for the rate -constant is used here. - -```{r p8} -p8 <- nafta(NAFTA_SOP_Attachment[["p8"]], parms.ini = c(k__iore_parent_sink = 1e-3)) -plot(p8) -print(p8) -``` - -# Examples where SFO was not selected for an abiotic study - -## Example on page 9, upper panel - -```{r p9a} -p9a <- nafta(NAFTA_SOP_Attachment[["p9a"]]) -plot(p9a) -print(p9a) -``` - -In this example, the residuals of the SFO indicate a lack of fit of this model, -so even if it was an abiotic experiment, the data do not suggest a simple -exponential decline. - -## Example on page 9, lower panel - -```{r p9b} -p9b <- nafta(NAFTA_SOP_Attachment[["p9b"]]) -plot(p9b) -print(p9b) -``` - -Here, mkin gives a longer slow DT50 for the DFOP model (17.8 days) than -PestDF (13.5 days). Presumably, this is related to the fact that -PestDF gives a negative value for the proportion of the fast degradation -which should be between 0 and 1, inclusive. This parameter is called -f in PestDF and g in mkin. In mkin, it is restricted to the interval from -0 to 1. - -## Example on page 10 - -```{r p10} -p10 <- nafta(NAFTA_SOP_Attachment[["p10"]]) -plot(p10) -print(p10) -``` - -Here, a value below N is given for the IORE model, because the data -suggests a faster decline towards the end of the experiment, which -appears physically rather unlikely in the case of a photolysis study. -It seems PestDF does not constrain N to values above zero, thus -the slight difference in IORE model parameters between PestDF and -mkin. - -# The DT50 was not observed during the study - -## Example on page 11 - -```{r p11} -p11 <- nafta(NAFTA_SOP_Attachment[["p11"]]) -plot(p11) -print(p11) -``` - -In this case, the DFOP fit reported for PestDF resulted -in a negative value for the slower rate constant, which is -not possible in mkin. The other results are in agreement. - -# N is less than 1 and the DFOP rate constants are like the SFO rate constant - -In the following three examples, the same results are obtained with mkin as -reported for PestDF. As in the case on page 10, the N values below 1 are deemed -unrealistic and appear to be the result of an overparameterisation. - - -## Example on page 12, upper panel - -```{r p12a} -p12a <- nafta(NAFTA_SOP_Attachment[["p12a"]]) -plot(p12a) -print(p12a) -``` - -## Example on page 12, lower panel - -```{r p12b} -p12b <- nafta(NAFTA_SOP_Attachment[["p12b"]]) -plot(p12b) -print(p12b) -``` - -## Example on page 13 - -```{r p13} -p13 <- nafta(NAFTA_SOP_Attachment[["p13"]]) -plot(p13) -print(p13) -``` - -# DT50 not observed in the study and DFOP problems in PestDF - -```{r p14} -p14 <- nafta(NAFTA_SOP_Attachment[["p14"]]) -plot(p14) -print(p14) -``` - -The slower rate constant reported by PestDF is negative, which is not -physically realistic, and not possible in mkin. The other fits give the same -results in mkin and PestDF. - -# N is less than 1 and DFOP fraction parameter is below zero - -```{r p15a} -p15a <- nafta(NAFTA_SOP_Attachment[["p15a"]]) -plot(p15a) -print(p15a) -``` - -```{r p15b} -p15b <- nafta(NAFTA_SOP_Attachment[["p15b"]]) -plot(p15b) -print(p15b) -``` - -In mkin, only the IORE fit is affected (deemed unrealistic), as the fraction -parameter of the DFOP model is restricted to the interval between 0 and 1 in -mkin. The SFO fits give the same results for both mkin and PestDF. - -# The DFOP fraction parameter is greater than 1 - -```{r p16} -p16 <- nafta(NAFTA_SOP_Attachment[["p16"]]) -plot(p16) -print(p16) -``` - -In PestDF, the DFOP fit seems to have stuck in a local minimum, as mkin finds -a solution with a much lower $\chi^2$ error level. As the half-life from the -slower rate constant of the DFOP model is larger than the IORE derived half-life, -the NAFTA recommendation obtained with mkin is to use the DFOP representative -half-life of 8.9 days. - -# Conclusions - -The results obtained with mkin deviate from the results obtained with PestDF -either in cases where one of the interpretive rules would apply, i.e. the -IORE parameter N is less than one or the DFOP k values obtained with PestDF are -equal to the SFO k values, or in cases where the DFOP model did not converge, -which often lead to negative rate constants returned by PestDF. - -Therefore, mkin appears to suitable for kinetic evaluations according to the -NAFTA guidance. - -# References |