What does (=>.) do in this example? Linda
Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Skip Cave <[email protected]> Date: 11/2/18 12:06 PM (GMT-05:00) To: "[email protected]" <[email protected]> Subject: Re: [Jprogramming] Square Roots and Extended Arithmetic Thanks for all the comments and help in understanding why trying to get an extended integer result from a square root is a bad idea. I think the functional symmetry of square *: and square root %: led me to subconsciously forget that the results of squared integers (all integers) are not symmetrical with the results of the square roots of integers (which are NOT all integers). I should remember this, since one of my favorite J idioms is the implicit verb (=>.) for finding integers in a list of floating point numbers: a=.2+i.20 %:a 1.41421 1.73205 2 2.23607 2.44949 2.64575 2.82843 3 3.16228 3.31662 3.4641 3.60555 3.74166 3.87298 4 4.12311 4.24264 4.3589 4.47214 4.58258 (=>.)%:a 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 a#~(=>.)%:a 4 9 16 Skip ---------------------------------------------------------------------- For information about J forums see https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7Cff92971a609a479e20a408d640dd2c50%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636767716000495561&sdata=G6T0f9%2BRqYnk1RdVs20bJpDQoL1LbSJfno1GhgqDoxg%3D&reserved=0 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
