reiterc@lafcol.UUCP (Reiter Clifford A) (04/19/88)
Here are some "light" APL expressions which highlight some of the
extended features of Sharp APL/PC which I have found useful. (I think
these are extensions.) I thought some of the new Sharp APL users would
like to experiment with some of these.
COMPLEX NUMBERS
------- -------
(-1)*.5
1o(-1)oo1
A is ((-8)+ 4 4 rho iota 16)*.5 comment: on the union keyboard quaddiv
is alt =,alt back sp,alt l
and quadPP uses lower case P's
quadPP is 5 ----- ----
quaddiv A
A+.x quaddiv A
quadPP is 10
GCD
---
I is iota 8
I jot.or I
(*1)or 1.5x*1
(*1)or o1 comment: e or pi
(go ahead, try it with complex numbers)
ENCLOSED ARRAYS
-------- ------
quadPS is 0,0,(-2),(-2) comment: the negatives are needed and quadPS
uses
lower case P and S
----- ----
A is <3 4 rho iota 12
B is <2 2 rho 1 0 0
A,B
4 5 rho A,B
<<<<<<<<<'me' comment: for the introverted
EXTENDING AN AXIS OF LENGTH 1
--------- -- ---- -- ------ -
A is ?3 3 rho 10
V is ? 3 rho 10
B is 1 3 rho V
A+.xV
A+.xB
How is V different from >,<V ?
Straight forward frequency counts of the occurrences of the elements of
W
in a data vector A is given by:
FREQ is +/[1] A jot.= W
Faster by 30% (roughly) is:
FREQ is A+.=>,<W comment: isn't it pretty
Faster is:
FREQ is +/ W jot.= A
Faster still is the suggestions about mode made some weeks ago.
Clifford Reiter reiterc@lafcol.UUCP
Mathematics Department
Lafayette College