CtfFind

Ctffind and xmipp_convert_spi22ccp4

Ctffind uses the header record number 54 (known as MACHST) to guess the machine architecture in which the file was created (usually small or big endian). The definition of MACHST is

 
The machine stamp is a 32-bit quantity containing a set of four `nibbles' (half-bytes)---only half
 the space is used. Each nibble is a number specifying the representation 
of (in C terms) double (d) , float (f), int (i) and unsigned char (c) types. 
Thus each stamp is of the form 0xdfic0000. 
The values for the floating point nibbles may be taken from the list (following HDF):
1 	Big-endian ieee
2 	VAX
3 	Cray
4 	Little-endian ieee
5 	Convex native
6 	Fujitsu VP

this definition is ambiguous and can be interpreted in two ways, of course xmipp and ctffind use different conventions. A work around this problem is to define the environment variable NATIVEMTZ

If you use bash

export NATIVEMTZ=kk

If you use csh

setenv NATIVEMTZ kk

-- Main.RobertoMarabini - 08 Oct 2008