From 31ebb3f994074148092c9309eba8c8258a05249f Mon Sep 17 00:00:00 2001
From: Stefan Mahr <stefan.mahr@sphairon.com>
Date: Tue, 4 Jun 2013 15:50:15 +0200
Subject: [PATCH] matlab: add far-field plot helper functions

---
 matlab/plotFF3D.m | 68 +++++++++++++++++++++++++++++++++++++++++++
 matlab/plotFFdB.m | 74 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 142 insertions(+)
 create mode 100644 matlab/plotFF3D.m
 create mode 100644 matlab/plotFFdB.m

diff --git a/matlab/plotFF3D.m b/matlab/plotFF3D.m
new file mode 100644
index 0000000..5d76357
--- /dev/null
+++ b/matlab/plotFF3D.m
@@ -0,0 +1,68 @@
+function h = plotFF3D(nf2ff,varargin)
+%  h = plotFF3D(nf2ff,varargin)
+%
+%  plot normalized 3D far field pattern
+%
+% input:
+%   nf2ff:      output of CalcNF2FF
+%
+% variable input:
+%   'cellelement': - use element from cell array
+%                  - default is 1
+%   'logscale':    - if set, show farfield with logarithmic scale
+%                  - set the dB value for point of origin
+%                  - values below will be clamped
+%
+%   example:
+%       plotFF3D(nf2ff, 'cellelement', 2, 'logscale', -20)
+%
+%       see examples/NF2FF/infDipol.m
+%
+% See also CalcNF2FF
+% 
+% openEMS matlab interface
+% -----------------------
+% author: Thorsten Liebig, Stefan Mahr
+
+% defaults
+logscale = [];
+cellelement = 1;
+
+for n=1:2:numel(varargin)
+    if (strcmp(varargin{n},'logscale')==1);
+        logscale = varargin{n+1};
+    elseif (strcmp(varargin{n},'cellelement')==1);
+        cellelement = varargin{n+1};
+    end
+end
+
+E_far_normalized = nf2ff.E_norm{cellelement} / max(nf2ff.E_norm{cellelement}(:));
+
+if ~isempty(logscale)
+    E_far_normalized = 20*log10(E_far_normalized)/-logscale + 1;
+    ind = find ( E_far_normalized < 0 );
+    E_far_normalized(ind) = 0;
+    titletext = sprintf('electrical far field [dB] @ f = %e Hz',nf2ff.freq(cellelement));
+else
+    titletext = sprintf('electrical far field [V/m] @ f = %e Hz',nf2ff.freq(cellelement));
+end
+
+[theta,phi] = ndgrid(nf2ff.theta,nf2ff.phi);
+x = E_far_normalized .* sin(theta) .* cos(phi);
+y = E_far_normalized .* sin(theta) .* sin(phi);
+z = E_far_normalized .* cos(theta);
+%figure
+h = surf( x,y,z, E_far_normalized );
+set(h,'EdgeColor','none');
+axis equal
+
+title( titletext );
+xlabel( 'x' );
+ylabel( 'y' );
+zlabel( 'z' );
+
+if (nargout == 0)
+  clear h;
+end
+
+end
diff --git a/matlab/plotFFdB.m b/matlab/plotFFdB.m
new file mode 100644
index 0000000..a3c6cb8
--- /dev/null
+++ b/matlab/plotFFdB.m
@@ -0,0 +1,74 @@
+function h = plotFFdB(nf2ff,varargin)
+%  h = plotFFdB(nf2ff,varargin)
+%
+%  plot far field pattern in dBi
+%
+% input:
+%   nf2ff:      output of CalcNF2FF
+%
+% variable input:
+%   'cellelement': - use element from cell array
+%                  - default is 1
+%   'xaxis':       - 'phi' (default) or 'theta'
+%   'param':       - array positions of parametric plot
+%                  - if xaxis='phi', theta is parameter, and vice versa
+%                  - default is 1
+%
+%   example:
+%       plotFFdB(nf2ff, 'cellelement', 2, ...
+%                       'xaxis', 'phi', 'param', [1 46 91])
+%
+%       see examples/NF2FF/infDipol.m
+%
+% See also CalcNF2FF
+% 
+% openEMS matlab interface
+% -----------------------
+% author: Thorsten Liebig, Stefan Mahr
+
+% defaults
+cellelement = 1;
+xaxis = 'phi';
+param = 1;
+
+for n=1:2:numel(varargin)
+    if (strcmp(varargin{n},'cellelement')==1);
+        cellelement = varargin{n+1};
+    elseif (strcmp(varargin{n},'xaxis')==1);
+        xaxis = varargin{n+1};
+    elseif (strcmp(varargin{n},'param')==1);
+        param = varargin{n+1};
+    end
+end
+
+D_log = nf2ff.E_norm{cellelement} / max(nf2ff.E_norm{cellelement}(:));
+D_log = 20*log10(D_log) + 10*log10(nf2ff.Dmax);
+
+if (strcmp(xaxis,'theta')==1);
+    xax = nf2ff.theta;
+    yax = D_log(:,param);
+    parval = nf2ff.phi(param);
+    param = 'phi';
+elseif (strcmp(xaxis,'phi')==1);
+    xax = nf2ff.phi;
+    yax = D_log(param,:);
+    parval = nf2ff.theta(param);
+    param = 'theta';
+end
+
+%figure
+h = plot( xax / pi * 180 , yax );
+xlabel( sprintf('%s (deg)',xaxis ));
+ylabel( 'directivity (dBi)');
+
+createlegend = @(d)sprintf("%s = %3.1f",param,d / pi * 180);
+legendtext = arrayfun(createlegend,parval,'UniformOutput',0);
+legend( legendtext );
+title( sprintf('far field pattern @ f = %e Hz',nf2ff.freq(cellelement)) );
+grid on;
+
+if (nargout == 0)
+  clear h;
+end
+
+end