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Functions to combine and adjust the outputs of the fourthcorner and randtest.rlq functions created using permutational models 2 and 4 (sequential approach).

Usage

combine.randtest.rlq(obj1, obj2, ...)
combine.4thcorner(four1,four2)
p.adjust.4thcorner(x, p.adjust.method.G = p.adjust.methods,
p.adjust.method.D = p.adjust.methods, p.adjust.D = c("global",
"levels"))

Arguments

four1

an object of the class 4thcorner created with modeltype = 2 (or 4)

four2

an object of the class 4thcorner created with modeltype = 4 (or 2)

obj1

an object created with randtest.rlq and modeltype = 2 (or 4)

obj2

an object created with randtest.rlq and modeltype = 4 (or 2)

x

an object of the class 4thcorner

p.adjust.method.G

a string indicating a method for multiple adjustment used for output tabG, see p.adjust.methods for possible choices

p.adjust.method.D

a string indicating a method for multiple adjustment used for output tabD/tabD2, see p.adjust.methods for possible choices

p.adjust.D

a string indicating if multiple adjustment for tabD/tabD2 should be done globally or only between levels of a factor ("levels", as in the original paper of Legendre et al. 1997)

...

further arguments passed to or from other methods

Details

The functions combines the outputs of two objects (created by fourthcorner and randtest.rlq functions) as described in Dray and Legendre (2008) and ter Braak et al (2012).

Value

The functions return objects of the same class than their argument. They simply create a new object where pvalues are equal to the maximum of pvalues of the two arguments.

References

Dray, S. and Legendre, P. (2008) Testing the species traits-environment relationships: the fourth-corner problem revisited. Ecology, 89, 3400--3412.

ter Braak, C., Cormont, A., and Dray, S. (2012) Improved testing of species traits-environment relationships in the fourth corner problem. Ecology, 93, 1525--1526.

Author

Stéphane Dray stephane.dray@univ-lyon1.fr

Examples

data(aravo)
four2 <- fourthcorner(aravo$env, aravo$spe, aravo$traits, nrepet=99,modeltype=2)
four4 <- fourthcorner(aravo$env, aravo$spe, aravo$traits, nrepet=99,modeltype=4)
four.comb <- combine.4thcorner(four2,four4)
## or directly :
## four.comb <- fourthcorner(aravo$env, aravo$spe, aravo$traits, nrepet=99,modeltype=6)
summary(four.comb)
#> Fourth-corner Statistics
#> ------------------------
#> Permutation method  Comb. 2 and 4  ( 99  permutations)
#> 
#> Adjustment method for multiple comparisons:   holm 
#>               Test Stat           Obs     Std.Obs     Alter Pvalue Pvalue.adj  
#> 1  Aspect / Height    r  -0.045735104 -1.07962114 two-sided   0.32       1.00  
#> 2   Slope / Height    r   0.094917344  1.94978334 two-sided   0.08       1.00  
#> 3    Form / Height    F  15.219879474  3.23795242   greater   0.02       0.72  
#> 4   PhysD / Height    r   0.113164322  1.98108834 two-sided   0.04       1.00  
#> 5   ZoogD / Height    F  15.227717714  1.67606996   greater   0.11       1.00  
#> 6    Snow / Height    r  -0.271739531 -2.80497356 two-sided   0.02       0.72  
#> 7  Aspect / Spread    r  -0.044170141 -1.55510898 two-sided   0.11       1.00  
#> 8   Slope / Spread    r  -0.017325425 -0.77364418 two-sided   0.47       1.00  
#> 9    Form / Spread    F   5.548173196  0.22476723   greater   0.27       1.00  
#> 10  PhysD / Spread    r  -0.051680330 -0.93941452 two-sided   0.30       1.00  
#> 11  ZoogD / Spread    F   0.120114487 -1.01756970   greater   0.93       1.00  
#> 12   Snow / Spread    r   0.065634673  0.73407808 two-sided   0.49       1.00  
#> 13  Aspect / Angle    r  -0.090837201 -1.90874050 two-sided   0.07       1.00  
#> 14   Slope / Angle    r   0.100281966  2.29945221 two-sided   0.04       1.00  
#> 15    Form / Angle    F  30.664664234  7.89119483   greater   0.01       0.48  
#> 16   PhysD / Angle    r   0.221380084  4.55626644 two-sided   0.01       0.48  
#> 17   ZoogD / Angle    F  28.051040522  3.16689819   greater   0.02       0.72  
#> 18    Snow / Angle    r  -0.269613756 -2.60618791 two-sided   0.02       0.72  
#> 19   Aspect / Area    r   0.031237858  0.74372511 two-sided   0.56       1.00  
#> 20    Slope / Area    r  -0.003864605 -0.03480649 two-sided   0.98       1.00  
#> 21     Form / Area    F  13.609309880  2.64227747   greater   0.03       0.93  
#> 22    PhysD / Area    r  -0.134371361 -2.07282497 two-sided   0.03       0.93  
#> 23    ZoogD / Area    F  49.672266332 14.29032202   greater   0.01       0.48  
#> 24     Snow / Area    r  -0.024574466 -0.43634412 two-sided   0.59       1.00  
#> 25  Aspect / Thick    r  -0.058466142 -1.38136315 two-sided   0.17       1.00  
#> 26   Slope / Thick    r   0.074151819  1.49324698 two-sided   0.14       1.00  
#> 27    Form / Thick    F  14.204346501  9.41120270   greater   0.01       0.48  
#> 28   PhysD / Thick    r   0.143161734  2.40103522 two-sided   0.02       0.72  
#> 29   ZoogD / Thick    F   2.825887968  0.57502021   greater   0.19       1.00  
#> 30    Snow / Thick    r  -0.154660144 -1.67889659 two-sided   0.11       1.00  
#> 31    Aspect / SLA    r  -0.007694551  0.05042614 two-sided   0.97       1.00  
#> 32     Slope / SLA    r  -0.235864886 -3.71571891 two-sided   0.01       0.48  
#> 33      Form / SLA    F 100.787472071 17.10157728   greater   0.01       0.48  
#> 34     PhysD / SLA    r  -0.275524984 -4.78051167 two-sided   0.01       0.48  
#> 35     ZoogD / SLA    F   0.984301951 -0.87404483   greater   0.89       1.00  
#> 36      Snow / SLA    r   0.481181824  7.94830614 two-sided   0.01       0.48  
#> 37 Aspect / N_mass    r  -0.061575524 -0.92404445 two-sided   0.36       1.00  
#> 38  Slope / N_mass    r  -0.201308154 -3.61596658 two-sided   0.01       0.48  
#> 39   Form / N_mass    F  70.042280400 13.06958338   greater   0.01       0.48  
#> 40  PhysD / N_mass    r  -0.212434381 -3.96829951 two-sided   0.01       0.48  
#> 41  ZoogD / N_mass    F  10.300092724  0.72853295   greater   0.17       1.00  
#> 42   Snow / N_mass    r   0.429271163  7.98893996 two-sided   0.01       0.48  
#> 43   Aspect / Seed    r   0.011598435  0.23319198 two-sided   0.85       1.00  
#> 44    Slope / Seed    r   0.077073974  1.63665889 two-sided   0.07       1.00  
#> 45     Form / Seed    F   5.561841954  0.50422249   greater   0.20       1.00  
#> 46    PhysD / Seed    r   0.078156305  1.37549602 two-sided   0.19       1.00  
#> 47    ZoogD / Seed    F   3.369068338  1.27476528   greater   0.12       1.00  
#> 48     Snow / Seed    r  -0.177640721 -1.92068825 two-sided   0.05       1.00  
#> 
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
plot(four.comb, stat = "G")