Primarily to make sure x is converted to mpfr vector if it is not,
when use.mpfr is set.
ecd.mpnum(object, x)ecd.ifelse(object, test, yes, no)
ecd.sapply(object, x, FUN, ...)
ecd.mcsapply(object, x, FUN, ...)
an object of ecd class
a vector of numeric or mpfr.
logical, test of ifelse.
return values for true elements of test
return values for false elements of test
the function to be applied to each element of x
optional arguments to FUN
a numeric or mpfr vector