Related by not exactly on topic: would anybody on the list be able to share old map files (not MTZ:s) with Convex, Cray, Fujitsu, or VAX reals/strings? I’d be interested to see what those files actually look(ed) like.
// Best wishes; Johan > On Nov 9, 2018, at 18:38, Zhijie Li <zhijie...@utoronto.ca> wrote: > > Hi all, > > On linux there are a few good GUI HEX editors. Here I’d like to recommend > BLESS, which conveniently displays all possible numerical interpretations of > the four bytes under cursor. It also allows the user to switch between big > endian or little endian through a checkbox. Unfortunately all floats are > assumed to be IEEE754, therefore VAX floats won’t be interpreted correctly. > ( The simplest way to convert vax to ieee float would be to write a little > program to do some bit operations. I’d be happy to take that as my weekend > project) > > > BTW, along the line of space efficiency, I can’t help noticing that the > miller indices are saved as float32 in mtz, as all other numbers in mtz. This > certainly have made mtz format a beautiful homogeneous data format ;). In > this particular case, if we have doubts about the reliability of the machine > stamp, trying to restore the miller indices would be a good way to test > hypotheses. > > Zhijie > > On Nov 9, 2018, at 9:04 PM, James Holton > <0000270165b9f4cf-dmarc-requ...@jiscmail.ac.uk> wrote: > >> As a beamline scientist I must say I am glad that diffraction image data is >> not usually stored as ASCII text. In fact, I am slowly warming to the idea >> of storing it as not just binary, but compressed formats. Problem, I'm sure >> will be that it won't be long before we forget how to decompress them, as >> most of the algorithms we are using aren't all that widespread. Probably >> around the same time future generations will curse us for using ASCII >> instead of unicode, which is a 16-bit standard. I'm sure we will be reviled >> for limiting ourselves so, just to save a factor of two in disk space. >> In situations like this I always use the unix "od" command. It makes >> everything "human readable" by converting the bytes into strings you can >> read. Then it is just a matter of figuring out what the bytes are. >> Unfortunately, "od" only decodes floats on the native platform, so if the >> mtz is from another platform (Windows vs Linux, for example), then you might >> need to do some swapping. Thus far, I have encountered files that require >> one of a few swapping strategies in order to make them work: >> >> 1 2 3 4 - no swapping >> >> 4 3 2 1 - reverse all bytes >> >> 3 4 1 2 - swap words and swap bytes within the words >> 2 1 4 3 - reverse of previous >> >> 2-1 1 4 3 - same as last, but if not all zero, decrement byte #2 before >> swapping >> 3 4 1 2+1 - same as 3412, but if not all zero increment byte #2 before >> swapping >> I'm sure there are other combinations, but the oldest MTZ I have is only >> from 1996. >> >> -James Holton >> MAD Scientist >> >> >> On 11/9/2018 4:47 AM, Eleanor Dodson wrote: >>> Anyone any idea what to do about this?? Created in 1992!! >>> Seems unreadable.. >>> >>> No CTYP lines input for file: 1 >>> Indices output even if all data items flagged "missing" >>> Warning, NOT all LABOUT data lines given >>> Warning: Machine stamp corrupted? Assuming native format. >>> >>>>>> CCP4 library signal library_file:End of File (Error) >>> >>> >>> To unsubscribe from the CCP4BB list, click the following link: >>> https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 >>> >> >> >> To unsubscribe from the CCP4BB list, click the following link: >> https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 >> > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 > Research Specialist @ Gonen Lab ____________________________________________________ UCLA * 615 Charles E. Young Drive South BSRB #347 * Los Angeles, CA 90095 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
