Fourier Transforms

Laurence Pearl pearl at bsm.biochemistry.ucl.ac.uk
Thu Jun 29 18:02:48 EST 1995


Toby Flint is suffering from not understanding Fourier Transforms.
But don't despair. The really fundamental thing about a Fourier Transform,
is that it is a mapping from one space to another, in which every point in
the one space carries information about every point in the other space and vice versa.
Mathematically thats all held in the h.x bit at the end of the classical
formula. But if you want a superb operational description of how Fourier
Tranforms operate in Crystallography (as opposed to signal processing or other
more boring applications) then look no further, for Kevin Cowtan,
not merely satisfied with giving us the all time best denstity modifcation
program I (at least) have ever used, has also produced an up-to-date
version of the Lipson and Cochrane optical transforms which provide more
than you need to know !!!

But Toby dear boy (I'm 40 next birthday so I'm allowed to call you dear boy)
you have to know how to use the Web, and call up :

http://www.yorvic.york.ac.uk/~cowtan/fourier/fourier.html

This is Kevin's 'Book of Fourier' and it is wonderful.

Remember, if you're lost in reciprocal space DONT PANIC !!



+----------------------------------------------------------------------------+
+  Laurence Pearl                                                            +
+                                                                            +
+  Section of Structural Biochemistry                                        +
+  Department of Biochemistry and Molecular Biology                          +
+  University College London                                                 +
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+  Phone +44-171-380-7372                                                    +
+  FAX   +44-171-380 7193                                                    +
+  E-Mail pearl at bsm.bioc.ucl.ac.uk                                           +
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