( ) , [ , , , , Q & A], , , $vectors$arrows , envfit(), . , , , @Didzis Elferts . plot(envfit(sol, NMDS.log)) , ( "" ). , , , . sqrt(r2), r2 - , . vegan , , . , ?envfit vegan:::ordiArrowMul(result_of_envfit).
, plot.envfit ggplot2:
library(vegan)
library(ggplot2)
library(grid)
data(dune)
# calculate distance for NMDS
NMDS.log<-log1p(dune)
set.seed(42)
sol <- metaMDS(NMDS.log)
scrs <- as.data.frame(scores(sol, display = "sites"))
scrs <- cbind(scrs, Group = c("hi","hi","hi","md","lo","hi","hi","lo","md","md",
"lo","lo","hi","lo","hi","md","md","lo","hi","lo"))
set.seed(123)
vf <- envfit(sol, NMDS.log, perm = 999)
vf:
> vf
***VECTORS
NMDS1 NMDS2 r2 Pr(>r)
Belper -0.78061195 -0.62501598 0.1942 0.174
Empnig -0.01315693 0.99991344 0.2501 0.054 .
Junbuf 0.22941001 -0.97332987 0.1397 0.293
Junart 0.99999981 -0.00062172 0.3647 0.022 *
Airpra -0.20995196 0.97771170 0.5376 0.002 **
Elepal 0.98959723 0.14386566 0.6634 0.001 ***
Rumace -0.87985767 -0.47523728 0.0948 0.429
.... <truncated>
, r2 NMDS1 NMDS2. :
spp.scrs <- as.data.frame(scores(vf, display = "vectors"))
spp.scrs <- cbind(spp.scrs, Species = rownames(spp.scrs))
p <- ggplot(scrs) +
geom_point(mapping = aes(x = NMDS1, y = NMDS2, colour = Group)) +
coord_fixed() +
geom_segment(data = spp.scrs,
aes(x = 0, xend = NMDS1, y = 0, yend = NMDS2),
arrow = arrow(length = unit(0.25, "cm")), colour = "grey") +
geom_text(data = spp.scrs, aes(x = NMDS1, y = NMDS2, label = Species),
size = 3)
:
