sdpar-methods {dti} | R Documentation |
This function estimates the parameters of a piecewise linear model for the dependence between error standard deviation and mean.
## S4 method for signature 'dtiData': sdpar(object,level=NULL,sdmethod="sd",interactive=TRUE)
object |
An object of class dtiData |
level |
Suggested value for slot level . As a default the value in object@level is used. The value determines the lower endpoint of the linear section in the model for error standard deviation as a function of the mean. |
sdmethod |
Method for estimating voxelwise standard deviations if replicates of zero weighted images are available, either "sd" or "mad" . |
interactive |
If TRUE a density of values in zero weighted images is plotted together with
the specification of the lower endpoint of the interval of linearity. A good choice of this point should correspond, if present, to the minimum between the first two modes of the density estimate. The value can be changed or accepted. If changed a new value for slot lambda is set. |
The function returns an object of class dtiData
.
Karsten Tabelow tabelow@wias-berlin.de
J"org Polzehl polzehl@wias-berlin.de
dtiData
,
readDWIdata
,
dti.smooth
,
dtiTensor
,
## Not run: demo(dti_art)