I define the following function to convert a t-value with degrees of freedom
DF to another t-value with different degrees of freedom fullDF:

tConvert <- function(tval, DF, fullDF) ifelse(DF>=1, qt(pt(tval, DF),
fullDF), 0)

It works as expected with the following case:

> tConvert(c(2,3), c(10,12), 12)
[1] 1.961905 3.000000

However, it gives me warning for the example below although the output is
still as intended:

> tConvert(c(2,3), c(0,12), 12)
[1] 0 3
Warning message:
In pt(q, df, lower.tail, log.p) : NaNs produced

I'm confused about the warning especially considering the fact that the
following works correctly without such warning:

> tConvert(2, 0, 12)
[1] 0

What am I missing?

Thanks,
Gang

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