Pointless does at least throw an error On 31 Jan 2012, at 13:19, Ian Tickle wrote:
> Eleanor > > Maybe the interpreter should at least throw an error if it encounters > a character (such as a bracket) that it can't interpret, as Jens > implied. > > Cheers > > -- Ian > > On 31 January 2012 10:16, Eleanor Dodson <c...@ysbl.york.ac.uk> wrote: >> Sorry, but it is a pain writing interpreters - at least it was in Fortran! >> and once you have one which recognises slashes as divisors, brackets can >> seem a step too far! >> >> Eleanor >> >> >> On 01/31/2012 08:46 AM, Phil Evans wrote: >>> >>> I had hoped that Pointless could replace Reindex, but doing some test it >>> seems that it also has problems with the syntax of reindex operators. I need >>> to look into this (but perhaps not immediately, sorry) >>> >>> Phil >>> >>> >>> On 31 Jan 2012, at 02:30, Jens Kaiser wrote: >>> >>>> Hi all, >>>> we encountered an odd behaviour of REINDEX. >>>> >>>> Snip form logfile: >>>> >>>> Data line--- reindex HKL (h+l)/2, -k, (h-l)/2 >>>> Data line--- end >>>> >>>> Reflections will be reindexed, and unit cell recalculated >>>> >>>> Reindexing transformation: >>>> (h' k' l') = ( h k l ) ( 1.00000 0.00000 1.00000 ) >>>> ( 0.00000 -1.00000 0.00000 ) >>>> ( 0.50000 0.00000 -0.50000 ) >>>> >>>> Obviously, the first line of the matrix is not what we intended to >>>> create. >>>> >>>> inputting the transformation as HKL h/2+l/2, -k, h/2-l/2 >>>> produces the desired result: >>>> >>>> Data line--- reindex HKL h/2+l/2, -k, h/2-l/2 >>>> Data line--- end >>>> >>>> Reflections will be reindexed, and unit cell recalculated >>>> >>>> Reindexing transformation: >>>> (h' k' l') = ( h k l ) ( 0.50000 0.00000 0.50000 ) >>>> ( 0.00000 -1.00000 0.00000 ) >>>> ( 0.50000 0.00000 -0.50000 ) >>>> >>>> >>>> >>>> Admittedly, the documentation does not use any brackets in the examples, >>>> but i would expect REINDEX either to throw an error or treat (h+l)/2 >>>> like (h-l)/2 but not treat them in the way encountered. >>>> >>>> Cheers, >>>> >>>> Jens >>>> >>>> >>>> -- >>>> +-------------------------------------+-----------------------------+ >>>> | Jens T. Kaiser | Office: +1(626)395-2662 | >>>> | California Institute of Technology | Lab: +1(626)395-8392 | >>>> | m/c 114-96 | Cell: +1(626)379-1650 | >>>> | 1200 E. California Blvd. | Xray: +1(626)395-2661 | >>>> | Pasadena, CA 91125 | Email: kai...@caltech.edu | >>>> | USA | Skype: jens.t.kaiser | >>>> +-------------------------------------+-----------------------------+
