Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / secs2d-0.0.8 / Utilities / Uinvfermidirac.m

diff --git a/octave_packages/secs2d-0.0.8/Utilities/Uinvfermidirac.m b/octave_packages/secs2d-0.0.8/Utilities/Uinvfermidirac.m
new file mode 100644 (file)
index 0000000..06d43f0
--- /dev/null
+++ b/octave_packages/secs2d-0.0.8/Utilities/Uinvfermidirac.m
@@ -0,0 +1,62 @@
+function [fd]=Uinvfermidirac(eta,par);
+
+%  [fd]=Uinvfermidirac(eta,par);
+
+% This file is part of 
+%
+%            SECS2D - A 2-D Drift--Diffusion Semiconductor Device Simulator
+%         -------------------------------------------------------------------
+%            Copyright (C) 2004-2006  Carlo de Falco
+%
+%
+%
+%  SECS2D is free software; you can redistribute it and/or modify
+%  it under the terms of the GNU General Public License as published by
+%  the Free Software Foundation; either version 2 of the License, or
+%  (at your option) any later version.
+%
+%  SECS2D is distributed in the hope that it will be useful,
+%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%  GNU General Public License for more details.
+%
+%  You should have received a copy of the GNU General Public License
+%  along with SECS2D; If not, see <http://www.gnu.org/licenses/>.
+
+% reshape eta into a sorted vector
+s = size(eta);
+eta = eta(:);
+[eta,order] = sort(eta);
+
+limits = Ufermidirac([-18,18],par);
+low  = limits(1);
+high = limits(2);
+
+etalow  = find(eta<=low);
+etahigh = find(eta>=high);
+etamid  = find((eta<high)&(eta>low));
+
+switch par
+case 1/2    
+    load fdhalf;
+    fd(etalow) =log(eta(etalow));
+    fd(etahigh)=(eta(etahigh)*3*sqrt(pi)/4).^(2/3);
+    if length(etamid)
+        fd(etamid) =log(linterp(a(:,2),exp(a(:,1)),eta(etamid)));
+    end
+case -1/2    
+    load fdmhalf;
+    fd(etalow) =log(eta(etalow));
+    fd(etahigh)=pi*(eta(etahigh).^2)/4;
+    if length(etamid)
+        fd(etamid) =log(linterp(a(:,2),exp(a(:,1)),eta(etamid)));
+    end
+otherwise
+    error(['wrong parameter: par=' num2str(par)])
+    return
+end
+
+
+% give answer in original order and shape
+fd(order) = fd;
+fd = reshape(fd,s);