typo: MAPC, MAPR and MAPS are elements 17-19 of the header, but you can see that anyway from the specification. Cheers
-- David On 15 September 2011 09:51, David Waterman <dgwater...@gmail.com> wrote: > Hi Pascal, > > The map data is a three dimensional array with dimensions [NC, NR, NS]. On > its own, this gives you no information about the grid pitch in the three > (crystallographic, not Cartesian) directions, which is determined in > fractional coordinates by the number of intervals. That is, along the X > direction the sampling interval has size 1/NX. Of course, you need the X, Y > and Z lengths (elements 11-13) to convert the fractional coordinate sizes to > real space units. There is a further conversion to take into account too: > the correspondence between X, Y, Z and C, R, S is not fixed by the format, > but is file dependent and described by MAPC, MAPR and MAPS (elements > 11-13). > > Hope this helps, > -- David > > > > On 15 September 2011 08:30, Pascal <pascal...@parois.net> wrote: > >> Hi, >> >> I am looking at the specifications of the ccp4 map file format and I am >> confused with the number of columns and the number of intervals. >> >> I assume that the number of columns is the grid size but what is the >> number of intervals (elements 8-9 in the header)? >> >> Regards, >> Pascal >> > >
