[ccp4bb]: Summary: Mapstretch

[Mark van Raaij <m.vanraaij@chem.leidenuniv.nl>]

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Dear colleagues,

In the end I simply multiplied the cell constants in the xplor ascii
file
as several people suggested.
I had looked at that file but hadn't recognised the line:
 6.72000E+02 6.72000E+02 6.72000E+02 9.00000E+01 9.00000E+01 9.00000E+01
as being cell parameters due to the exponential nature of the numbers...

Other suggestions:

Use program MAIN

Andrew Leslie has a jiffy, Tassos offers to write one, which he thinks
is
easy.

dvd:
write the map in an ascii format (e.g., EZD format with
MAPMAN); edit this file and multiply all three unit cell
lengths by 1.5; convert the map back into CCP4 or whatever
format with MAPMAN - i think this should work
come to think of it, it might even work if you change the
cell lengths with the CEll command inside MAPMAN and then
mappage the map

Robert Esnouf:
Add a line in bobscript
 transform map em by rotation 1.5 0 0 0 1.5 0 0 0 1.5;

Bart Hazes:
You can stretch a map equally in all dimensions by increasing all three
unit
cell parameters by the same amount. I'm not sure if this is easy to do
in the
map file header records but you can always backtransform to structure
factors,
make the changes to the MTZ header (SFTOOLS) and transform back.

Petr Leiman:
Make maps of different sizes and fit with the program SITUS, take the
one with 
the best fit.
I should have done this last one and will perhaps still do it later once
I get 
round to installing SITUS...

Thanks for your help and sorry for omitting some reactions,

Mark