Changeset 1029 for branches

Timestamp:

Oct 17, 2010 10:32:31 PM (13 years ago)

Author:

toby

Message:

fix FWHM calc

File:

• branches/sandbox/widplt (modified) (2 diffs)

branches/sandbox/widplt

@@ -563 +563 @@
                             }
                         }
-                        # assume FWHM add as square roots
+                        # Use polynomial of P. Thompson, D.E. Cox & J.B. Hastings,  
+                        # J. Appl. Cryst.,20,79-83, 1987 (GSAS manual 9/26/04 p157)
+                        # to compute composite FWHM
                         lappend tfwhmlist \
-                                [expr sqrt($gfwhm*$gfwhm + $lfwhm*$lfwhm)]
+                            [expr {
+                                   pow(
+                                       pow($gfwhm,5) + 
+                                       2.69269*pow($gfwhm,4)*$lfwhm + 
+                                       2.42843*pow($gfwhm,3)*pow($lfwhm,2) +
+                                       4.47163*pow($gfwhm,2)*pow($lfwhm,3) + 
+                                       0.07842*$gfwhm*pow($lfwhm,4) + 
+                                       pow($lfwhm,5)
+                                       , 0.2)
+                               }]
                     }
-                }
+                        }
                 if $lflag {
                     catch {
@@ -938 +949 @@
     set tantt [expr tan($tt * $torad ) ]
     set costt [expr cos($tt * $torad ) ]
-    return [expr sqrt \
-            (8.* log(2) * ($U * $tantt * $tantt + $V * $tantt + $W \
-            + $P / ($costt * $costt))) / 100.]
-}
+    return [expr {
+                  sqrt (8.* log(2) * 
+                        ($U * $tantt * $tantt + $V * $tantt + $W + 
+                         $P / ($costt * $costt))
+                        ) / 100.}]
+}
+
 proc LFWHM {tt X Y} {
     set pi 3.14159