*elempatchprevaction

To start the patch checker and move through several patches, changing the patch size, while using quality criteria given from a file:

*readqualitycriteria c:/criteria/mycriteria.txt
*createmark elems 1 displayed
*elementqualitysetup 1
*elempatchstartaction 0 1.0
*elempatchnextaction
*elempatchnextaction
*elempatchincraction
*elempatchprevaction
*elempatchdecraction
*elempatchstopaction
*elementqualityshutdown 1

Incorrect usage results in a Tcl error. To detect errors, you can use the catch command:

if { [ catch {command_name...} ] } {
   # Handle error
}