Error in uniroot(f = function(x) { : f() values at end points not of opposite sign

[Puzzled-Face]

Some tests have started to report problems with the use of uniroot. A typical warning is:

Warning (test-helpers_knitr.R:89:15): knit_print methods exist for all relevant classes and produce consistent output
Error for class StartingDose: Error in uniroot(f = function(x) { : 
  f() values at end points not of opposite sign

The warnings are all reported in test-helpers_knitr.R. The affected classes are

• StartingDose
• DualEndpointBeta
• DualEndpointEmax
• DualEndpointRW
• DualDesign
• TDDesign

No test fails as a result of this error.

The only calls to uniroot within the crmPack source code are on line 394 of Simulations-methods.R (summary-GeneralSimulations) and line 4009 of Design-methods.R (simulate-DADesign).

The error for StartingDose is particularly surprising as the class is not involved in any simulation.