Added new QENS model

lamp_mac/str_fit.pro

@@ -1974,6 +1974,23 @@ case uv[0] of
                            Pexplain[12] = 'Rotational diffusion constant (in E units)'
                      end
 
+;QENS_Mix2
+                 97: begin & formu ='Y = QENS_Mix2(X, P1, P2, P3, P4, P5, P6, P7) ;QENS delta + Lorentzian + random walk translation'
+                     npp     = 7                                                          ;Number of parameters
+                     editf   = 0                                                          ;Not editable formula
+                     fixpi   = [0,0,0,0,0,0,0]                                            ;Fixed params (definitively)
+                     txtpi   = ['P1.scale', 'P2.u2', 'P3.pos', 'P4.fixed', 'P5.fraction', 'P6.HWHM', 'P7.D']
+                     valpi   = ['I: 1 >0', 'u2: 0 >0', 'C: 0', 'f0: 0.5 >0<1', 'f1: 0.3 >0<1', $ ;Initial values
+                       'HWHM: 0.5 >0', 'D: 0.1 >0']
+                     Pexplain[1]  = 'Intensity scaling (arbitrary units).'
+                     Pexplain[2]  = 'u^2 for DW term'
+                     Pexplain[3]  = 'Position'
+                     Pexplain[4]  = 'Fraction of immobile protons [f0]'
+                     Pexplain[5]  = 'Fraction of protons contributing to Lorentzian [f1]'
+                     Pexplain[6]  = 'HWHM of Lorenzian'
+                     Pexplain[7]  = 'Self-diffusion constant [D] (in E/Q^2 units) for long-range translation'
+                   end
+
                  endcase
 
                  bsf=115
@@ -3725,9 +3742,9 @@ TBname=[TBname,       'QENS_IL1', 'QENS_IL2', 'QENS_IL3']
 TBname=[TBname,       'QENS_Fixed_JumpsNsites', 'QENS_Fixed_2JumpsNsites', 'QENS_Fixed_JumpsNsitesLogNormDist']
 ;SubIndex UV(5)        93                        94                         95
 ;
-;                      105                       
-TBname=[TBname,       'QENS_Mix1']
-;SubIndex UV(5)        96                       
+;                      105         106              
+TBname=[TBname,       'QENS_Mix1', 'QENS_Mix2']
+;SubIndex UV(5)        96          97          
 ;
 
 Flist=widget_button(row1 ,value='ADD a Function',/menu    ,font=ft_b_normal) ;         ,TBname IDX           ,Case IDX
@@ -3837,6 +3854,7 @@ but9 =widget_button(mau1 ,value='- Teubner-Strey'         ,font=ft_b_normal, uva
  but9=widget_button(but  ,value='- Fixed pop + Jumps between N & M sites in a circle '    ,font=ft_b_normal, uvalue=[40,103,leader,base0,Flist,94, mess])
  but9=widget_button(but  ,value='- Fixed pop + Jumps on N sites in a circle with log-norm distribution'    , uvalue=[40,104,leader,base0,Flist,95, mess], font=ft_b_normal)
  but9=widget_button(but  ,value='- Fixed pop + Long-range and confined translation + isotropic rotation'   , uvalue=[40,105,leader,base0,Flist,96, mess], font=ft_b_normal)
+ but9=widget_button(but  ,value='- Fixed pop + Lorentzian + Random-walk translation'                       , uvalue=[40,106,leader,base0,Flist,97, mess], font=ft_b_normal)
  bid =widget_button(but  ,value='---') & widget_control,bid,sens=0
 
  if Qmanual gt ' ' then begin
@@ -6638,6 +6656,51 @@ function QENS_Mix1, X, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12
 
 end
 
+
+function QENS_Mix2, X, P1, P2, P3, P4, P5, P6, P7
+  ;+
+  ;******************************************************************************
+  ;** Delta +
+  ;** Lorentzian +
+  ;** Random translational diffusion
+  ;**
+  ;**   This assumes 3 independent populations, each contributing to
+  ;**   a single type of motion. However there is no way to ensure
+  ;**   that P4+P5 < 1, so the fit can go to non-physical values
+  ;**   such that the fraction for the last component 1-P4-P5 < 0.
+  ;**
+  ;**   As the position of the delta can be between two energy values,
+  ;**   the intensity of the delta is shared into 2 deltas placed at those two energies.
+  ;**
+  ;** Parameters:
+  ;**   P1  = Scaling factor
+  ;**   P2  = u^2 for DW term
+  ;**   P3  = Center
+  ;**   P4  = Fraction of atoms contributing to delta
+  ;**   P5  = Fraction of atoms contributing to Lorentzian 
+  ;**   P6  = HWHM of Lorenzian function
+  ;**   P7  = D (self-diffusion coefficient in A^2*meV) 
+  ;-
+
+  common c_str_fitqens, func_resol, Qcurrent1D, Qcurrent2D, mig2, mig3, mig4, mig5
+
+  Y = QENS_delta(X, 1.0, 0.0, P3, P4) ;delta (area=1, DW=0, position, fraction=P4)
+
+  ;General Lorentzian function
+  Y += P5 * strnormLorentz(X, P3, P6)
+  
+  ;Random walk translation
+  hwhm = P7 * Qcurrent1D^2 
+  Y += (1-P4-P5) * strnormLorentz(X, P3, hwhm)
+
+  ;scaling & DW
+  Y *= P1
+  if P2 gt 0. then Y *= EXP((-P2*Qcurrent1D^2/3.)>(-70.))
+
+  return, Y
+
+end
+
 ;
 ;;End QENS functions
 ;******************************************************************************