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<mailto: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
