checkNegValueDS: Checks if a numeric variable has negative values
Description
this function is only called by the client function ds.glm.
Usage
checkNegValueDS(weights)
Value
a boolean; TRUE if the vector has one or more negative values and FALSE otherwise
Arguments
weights
a numeric vector
Author
Gaye, A.
Details
if a user sets the parameter 'weights' on the client site function ds.glm this
server side function is called to verify that the 'weights' vector does not have negative values
because no negative are allowed in weights.