3D yield response to fertilizers missing example

[adamhsparks]

In the vignette the text states:

The blue dots are observed data, and the tan surface is the fitted surface drawn by the rgl package).

However, there is no associated R code in the RMD file and rgl is not listed in the "Setup" section.

[kwstat]

Added this text:

Note: This image was created by manual manipulation of an rgl device. The manual manipulation makes this non-reproducible in an Rmd file. See the example for the sinclair.clover data for the code.

Is that sufficient?

[adamhsparks]

Makes sense to me and is more clear than it currently appeared.

Thanks!