[Jprogramming] Taylor coefficients dyad

[Zsbán Ambrus]

Let me ask some question on the builtins for Taylor coefficients.

Firstly, I don't understand how diadic (u t.) works.  Of the following
two phrases, the first one gives the correct result, and the second
one should give the same result according to the dictionary if I read
it right, but I get something else.  Why?

   ^t.i.6
1 1 0.5 0.166667 0.0416667 0.00833333
   1 ^t.i.6
_ 1 0.5 0.333333 0.25 0.2

Secondly, about the (u t:) dyad.  This one isn't defined in the
dictionary, but calling it doesn't usually result in an error.  Is
this some kind of undocumented feature?  Eg.

   $1 ^t:i.6
0
   $1 (^&2)t:i.6
6

All above examples are using:

   JVERSION
Engine: j701/2011-01-10/11:25
Library: 7.01.040
Platform: Linux 64
Installer: j701a_linux64.sh
InstallPath: /home/ambrus/local/j64-701

Ambrus