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damp [2010/11/02 01:00]
pac079 created
damp [2011/11/25 03:26]
rowlesmr fixed some formatting and added additional 's to fix auto colouring.
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 ====== GSAS-style Dampening Factors ====== ====== GSAS-style Dampening Factors ======
-Dampening factor for any refined value (lattice parameters, atomic positions etc.), for those who think that they know better than the least squares algorithm +Dampening factor for any refined value (lattice parameters, atomic positions etc.), for those who like to think that they know better than the least squares algorithm
-<code topas>macro Damp(DampFactor) { update = Val + (Change*(1/​Exp(DampFactor/​2)));​ } + 
-'​Rather than the true GSAS dampening [applied shift = (10-damp)/​10],​ an exponential function is used, scaled to useful dampening values of 0-9 +<code topas> 
-'​Useful dampening factors range from values of 0 (no dampening) to 9 (1% applied shift) +''​Rather than the true GSAS dampening [applied shift = (10-damp)/​10],​ an exponential function is used, scaled to useful dampening values of 0-9 
-'List of DampFactor,​AppliedChanges:​ 0,1; 1,0.607; 2,0.368; 3,0.223; 4,0.135; 5,0.082; 6,0.50; 7,0.030; 8,0.018; 9,0.011 +''​Useful dampening factors range from values of 0 (no dampening) to 9 (1% applied shift) 
-'e.g. A simple lattice parameter refinement with dampening factors of 9, 8, 7, 6, 5, 4, 3, 2, 1 and 0 +''List of DampFactor,​AppliedChanges:​ 0,1; 1,0.607; 2,0.368; 3,0.223; 4,0.135; 5,0.082; 6,0.50; 7,0.030; 8,0.018; 9,0.011 
-' ​    ​converges in 422, 271, 173, 111, 71, 45, 28, 17, 10 and 5 cycles, respectively +''e.g. A simple lattice parameter refinement with dampening factors of 9, 8, 7, 6, 5, 4, 3, 2, 1 and 0 
-'​Example of use: site O1 x @  0.30696 Damp(3) y 0 z 0.25 occ O-2 1 beq @ 2 Damp(7)</​code>​+'' ​    ​converges in 422, 271, 173, 111, 71, 45, 28, 17, 10 and 5 cycles, respectively 
 +''​Example of use:  
 +'' ​site O1 x @  0.30696 Damp(3) y 0 z 0.25 occ O-2 1 beq @ 2 Damp(7) 
 + 
 +macro Damp(DampFactor)  
 +
 +   ​update = Val + (Change*(1/​Exp(DampFactor/​2)));​  
 +
 +</​code>​

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