Might I suggest changing the variable name from A to SQ? Then you have the calculation of SQ[i] = i * i.
On Fri, Oct 24, 2014 at 9:32 PM, David Crayford <dcrayf...@gmail.com> wrote: > On 25/10/2014 3:35 AM, Bob Rutledge wrote: >> >> I would guess that, as previously suggested, >> >> for i = 1, count do a[i] = a[i] * i end >> >> would really rather be >> >> for i = 1, count do a[i] = i * i end >> > > Good eye Bob! When I copy and pasted the snippet into the e-mail it dropped > the square brackets. When I edited the code I inserted a bug! > > Bloody square brackets will be the death of me! > > >> Bob >> >> Barkow, Eileen wrote: >>> >>> I keep getting this error both in MVS and UNIX. >>> >>> LUA: //'xcics.lua4z.samplib(cpu)':4: attempt to perform arithmetic on >>> field '? ' (a nil value) stack traceback: >>> //'xcics.lua4z.samplib(cpu)':4: in main chunk >>> ÝC¨: ? *** >>> -----Original Message----- >>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On >>> Behalf Of Bass, Walter W >>> Sent: Friday, October 24, 2014 2:21 PM >>> To: IBM-MAIN@LISTSERV.UA.EDU >>> Subject: Re: [ANN] Lua4z: the Lua programming language on z/OS, with >>> batteries >>> >>>> -----Original Message----- >>>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On >>>> Behalf Of David Crayford >>>> Sent: Thursday, October 23, 2014 10:08 PM >>>> To: IBM-MAIN@LISTSERV.UA.EDU >>>> Subject: Re: [ANN] Lua4z: the Lua programming language on z/OS, with >>>> batteries> >>>> >>>> >>> >>> <snip> >>> >>>> OK, let's try simple matrix multiplication which should test both array >>>> access and math. >>>> >>>> /* REXX */ >>>> arg count >>>> if count = "" then count = 1000000 >>>> start = sysvar("SYSCPU") >>>> do i = 1 to count >>>> a.i = i * i >>>> end >>>> say 'CPU time = 'sysvar("SYSCPU") - start >>>> >>>> CPU time = 3.57 >>>> >>>> local t = require("timer")() >>>> local count = arg[1] or 1000000 >>>> local a = {} >>>> for i = 1, count do a[i] = a[i] * i end >>>> t:print_elapsed() >>>> >>>> elapsed time: 0.131965 >>>> >>>> >>>> That's a huge difference, two orders of magnitude. >>>> >>> >>> <snip remainder> >>> >>> Maybe I'm just showing my ignorance of the Lua language syntax, but this >>> statement: " a[i] = a[i] * i " >>> >>> Does not appear to be the equivalent to the REXX statement: >>> " a.i = i * i " >>> >>> In fact, I would expect that the above Lua statement is actually >>> multiplying i by an uninitialized variable "a[i]". Assuming the above code >>> executes without error, then due to the principle of least astonishment, I >>> would imagine that this uninitialized value is assumed to be zero. >>> >>> If that IS what is happening, it will of course be MUCH faster to compute >>> i * 0 than to compute i squared. >>> >>> Can someone with Lua syntax knowledge please enlighten me? >>> >>> Thanks, >>> Bill Bass >>> United HealthCare / Optum >>> >>> >>> This e-mail, including attachments, may include confidential and/or >>> proprietary information, and may be used only by the person or entity to >>> which it is addressed. If the reader of this e-mail is not the intended >>> recipient or his or her authorized agent, the reader is hereby notified that >>> any dissemination, distribution or copying of this e-mail is prohibited. If >>> you have received this e-mail in error, please notify the sender by replying >>> to this message and delete this e-mail immediately. >>> >>> >>> ---------------------------------------------------------------------- >>> For IBM-MAIN subscribe / signoff / archive access instructions, send >>> email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN >>> >>> ---------------------------------------------------------------------- >>> For IBM-MAIN subscribe / signoff / archive access instructions, >>> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN >> >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
