forked from vincentarelbundock/Rdatasets
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathglymet.html
101 lines (64 loc) · 2.96 KB
/
glymet.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>R: Glyphosate and metsulfuron-methyl tested on algae.</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes" />
<link rel="stylesheet" type="text/css" href="R.css" />
</head><body><div class="container">
<table width="100%" summary="page for glymet"><tr><td>glymet</td><td style="text-align: right;">R Documentation</td></tr></table>
<h2>Glyphosate and metsulfuron-methyl tested on algae.</h2>
<h3>Description</h3>
<p>The dataset has 7 mixtures, 8 dilutions, two replicates and 5 common control controls.
Four observations are missing, giving a total of 113 observations.
</p>
<h3>Usage</h3>
<pre>data(glymet)</pre>
<h3>Format</h3>
<p>A data frame with 113 observations on the following 3 variables.
</p>
<dl>
<dt><code>dose</code></dt><dd><p>a numeric vector of dose values</p>
</dd>
<dt><code>pct</code></dt><dd><p>a numeric vector denoting the grouping according to the mixtures percentages</p>
</dd>
<dt><code>rgr</code></dt><dd><p>a numeric vector of response values (relative growth rates)</p>
</dd>
</dl>
<h3>Details</h3>
<p>The dataset is analysed in Soerensen et al (2007).
The concentration addition model can be entertained for this dataset.
</p>
<h3>Source</h3>
<p>The dataset is kindly provided by Nina Cedergreen, Department of Agricultural Sciences,
Royal Veterinary and Agricultural University, Denmark.
</p>
<h3>References</h3>
<p>Soerensen, H. and Cedergreen, N. and Skovgaard, I. M. and Streibig, J. C. (2007)
An isobole-based statistical model and test for synergism/antagonism in binary mixture toxicity experiments,
<em>Environmental and Ecological Statistics</em>, <b>14</b>, 383–397.
</p>
<h3>Examples</h3>
<pre>
## Fitting the model with freely varying ED50 values
glymet.free <- drm(rgr~dose, pct, data = glymet,
fct = LL.3(), pmodels = list(~factor(pct) , ~1, ~factor(pct)))
## Lack-of-fit test
modelFit(glymet.free) # acceptable
summary(glymet.free)
## Plotting isobole structure
isobole(glymet.free, exchange=0.01)
## Fitting the concentration addition model
glymet.ca <- mixture(glymet.free, model = "CA")
## Comparing to model with freely varying e parameter
anova(glymet.ca, glymet.free) # borderline accepted
## Plotting isobole based on concentration addition
isobole(glymet.free, glymet.ca, exchange = 0.01) # acceptable fit
## Fitting the Hewlett model
glymet.hew <- mixture(glymet.free, model = "Hewlett")
### Comparing to model with freely varying e parameter
anova(glymet.ca, glymet.hew)
# borderline accepted
# the Hewlett model offers no improvement over concentration addition
## Plotting isobole based on the Hewlett model
isobole(glymet.free, glymet.hew, exchange = 0.01)
# no improvement over concentration addition
</pre>
</div></body></html>