Introduction
CGGC performs permutation tests to assess differences
between groups of growth curves. It calculates all pairwise
comparisons between two or more groups of growth curves.
To conduct CGGC on your own data, simply type data into the box below
or paste data into the box from a text document or Excel spreadsheet.
Accurate pvalues
can be obtained by setting the number of permutations to some large value.
We suggest 100 permutations for initial testing but at least 10000
permutations for definitive and publishable results.
Data Requirements:
The first row contains columns headers.
Each other row of data contains:
In the first column a group indicator (for example, mouse strain in the example below).
All other columns contain data for individual time points.
Missing data needs to be represented by the 2 letters "NA", without the quotes.
Some Example data is:
Strain D0 D1 D3 D5 D7 D9 D11
BALB/c 4.01 3.96 2.62 2.59 2.13 1.47 0
BALB/c 4 3.91 3.94 3.81 2.82 1.74 0.98
BALB/c 4.32 4.93 4.15 NA 3.88 1.82 0.93
C57B/6 4.7 3.61 3.61 3.68 3.5 1.43 0
C57B/6 5.33 5.58 4.26 4.55 3.77 2.19 0.95
C57B/6 4.1 4.38 3.42 3.43 2.59 NA NA
C.lmr1/2 4.57 3.51 3.72 2.55 2.05 0 0
C.lmr1/2 3.91 3.58 2.94 2.87 2.26 1.2 0.97
C.lmr1/2 4.79 3.82 4.21 3.78 2.43 1.75 0
The output from this example is:
The number of lines of data processed (excluding the heading line) = 9
The number of unique groups entered = 3
The number of time points entered = 7
The number of permutations selected = 10000
Group1 Group2 Stat P.Value adj.P.Value
1 BALB/c C.lmr1/2 0.603 0.52 1
2 BALB/c C57B/6 0.598 0.64 1
3 C.lmr1/2 C57B/6 1.203 0.39 1
(Your P values may vary slightly.)
Enter your data here:

Authors
Method designed by Gordon Smyth and Russell Thompson with web interface by Keith Satterley.
Method
CGGC computes a permutation pvalue for each pair of groups, using the average
tstatistic between the groups as the test statistic.
ttests are computed for each time and averaged to obtain the permutation statistic.
The actual computations are performed by the compareGrowthCurves function
of the statmod R package.
The method is described and used in the references Elso et al (2004)
and Baldwin et al (2007) listed below.
Citation
If you use results from this page in a publication, please describe the test as the
"CGGC permutation test" and cite one of the following two papers:
 Elso, C. M., Roberts, L. J., Smyth, G. K., Thomson, R. J., Baldwin, T. M., Foote, S. J., and Handman, E. (2004).
Leishmaniasis host response loci (lmr13) modify disease severity through a Th1/Th2independent pathway.
Genes and Immunity 5, 93100.
[PubMed]
 Baldwin, T., Sakthianandeswaren, A., Curtis, J., Kumar, B., Smyth, G. K., Foote, S., and Handman, E. (2007).
Wound healing response is a major contributor to the severity of cutaneous leishmaniasis in the ear model of infection.
Parasite Immunology 29, 501513.
[PubMed]
Comments/Questions? Contact Gordon Smyth.
Last modified:
17 March 2019
