dsm.cor {dsm} | R Documentation |
Once a DSM has been fitted to data, this function can be used to check for autocorrelation in the residuals.
dsm.cor( dsm.obj, Transect.Label = "Transect.Label", Segment.Label = "Segment.Label", max.lag = 10, resid.type = "scaled.pearson", fun = cor, ylim = c(0, 1), subset = "all", ... )
dsm.obj |
a fitted dsm object. |
Transect.Label |
label for the transect (default: |
Segment.Label |
label for the segments (default: |
max.lag |
maximum lag to calculate at. |
resid.type |
the type of residuals used, see |
fun |
the function to use, by default |
ylim |
user defined limits in y direction. |
subset |
which subset of the data should the correlation function be calculated on? |
... |
other options to pass to |
a plot or a vector of fun
applied at the lags.
Within each Transect.Label
, segments will be sorted according to their Segment.Labels
. This may require some time to get right for your particular data. If one has multiple surveys where transects are revisited, for example, one may want to make Transect.Label
a unique transect-survey id. Neither label need to be included in the model, they must just be present in the $data
field in the model. This usually means that they have to be in the segment data passed to dsm
.
The current iteration of this function will only plot correlations nicely, other things are up to you but you can get the function to return the data (by assigning the result to an object).
If there are NA values in the residuals then the correlogram will not be calculated. This usually occurs due to NA values in the covariates (so the smoother will not have fitted values there). Code like 'any(is.na(dsm.obj$data))' might be helpful.
David L. Miller
library(Distance) library(dsm) # load the data, see ?mexdolphins data(mexdolphins) # fit a model hr.model <- ds(distdata, max(distdata$distance), key = "hr", adjustment = NULL) mod1<-dsm(count~s(x,y), hr.model, segdata, obsdata) # look at lag 1 differences up to a maximum of lag 9, using deviance # residuals dsm.cor(mod1, resid.type="deviance", max.lag=9, Segment.Label="Sample.Label")