added map projection plot to itaCoordinates

kernel/ClassStuff/@itaCoordinates/plot_map_projection.m

+function varargout = plot_map_projection(this, varargin)
+%PLOT_MAP_PROJECTION - Plot a map projection of data on a sphere
+%  This function plots a map projection for a dataset on a full or 
+%  partial spherical surface
+%
+%  Syntax:
+%   plot_map_projection(this, data, options)
+%
+%   Options (default):
+%           'proj' ('wagner4')   : Specifies the projection type (See mapping toolbox documentation for supported projections)
+%           'phi0' (0)           : Longitute angle phi0 = 0 -> x-axis at origin of the map
+%           'shading' ('interp') : Specifies the shading algorithm
+%           'db' (false)         : db plot
+%           'limits' ([])        : Colorbar limits
+%
+%  Example:
+%   plot_map_projection(this, data, 'db', 'limits', [-50, 0])
+%
+%  See also:
+%   itaCoordinates, ita_sph_sampling, surf, scatter
+%
+%   Reference page in Help browser 
+%        <a href="matlab:doc plot_map_projection">doc plot_map_projection</a>
+
+% <ITA-Toolbox>
+% This file is part of the ITA-Toolbox. Some rights reserved. 
+% You can find the license for this m-file in the license.txt file in the ITA-Toolbox folder. 
+% </ITA-Toolbox>
+
+
+% Author: Marco Berzborn -- Email: marco.berzborn@akustik.rwth-aachen.de
+% Created:  06-Jun-2017 
+
+sArgs = struct('pos1_data','double',...
+               'phi0',0,...
+               'proj','wagner4',...
+               'db',false,...
+               'shading','interp',...
+               'limits',[],...
+               'fgh',[],...
+			   'colormap',[]);
+[data,sArgs] = ita_parse_arguments(sArgs,varargin);
+
+% convert to longitude, latitude coordinates required by the mapping toolbox
+[azi,ele,~] = cart2sph(this.x,this.y,this.z);
+lat = ele*180/pi;
+% if phi0 = 0, x = 1 is the origin of the map at lat = 0, lon = 0
+lon = (azi-sArgs.phi0)*180/pi;
+% longitude, latitude limits for the plot
+latLim = [min(lat),max(lat)];
+lonLim = [min(lon),max(lon)];
+
+if isempty(sArgs.fgh)
+    sArgs.fgh = figure();
+end
+% project sampling coordinates
+mstruct = defaultm(sArgs.proj);
+mstruct.origin = [0,0];
+mstruct = defaultm(mstruct);
+mstruct.maplonlimit = lonLim;
+mstruct.maplatlimit = latLim;
+mstruct.flinewidth = 1;
+mstruct.flatlimit = latLim;
+mstruct.flonlimit = lonLim;
+[x,y] = mfwdtran(mstruct,lat,lon);
+
+LatTicks = 0:30:latLim(2);
+LatTicks = [-fliplr(30:30:abs(latLim(1))),LatTicks(1:end)];
+LonTicks = 0:50:lonLim(2);
+LonTicks = [-fliplr(50:50:abs(lonLim(1))),LonTicks(1:end)];
+
+[latTicks,lonTicks] = meshgrid(latLim(1),LonTicks);
+[XTicks,~] = mfwdtran(mstruct,latTicks,lonTicks);
+[latTicks,lonTicks] = meshgrid(LatTicks,lonLim(2));
+[~,YTicks] = mfwdtran(mstruct,latTicks,lonTicks);
+
+
+% calculate delaunay triangulation for the meshgrid
+tri = delaunay(x,y);
+if sArgs.db
+    data = 20*log10(abs(data));
+else
+    data = abs(data);
+end
+trisurf(tri,x,y,data);
+
+cb = colorbar;
+cb.Label.String = 'Magnitude';
+if ~isempty(sArgs.limits)
+    caxis(sArgs.limits);
+end
+
+
+% use custom colormap if given
+if ~isempty(sArgs.colormap)
+	colormap(sArgs.fgh,sArgs.colormap);
+end
+% set shading, will be set to interpolate by default
+shading(sArgs.shading);
+
+% change view to top view
+view([0,90])
+
+% create axes corresponding to the chosen map projection
+axh = axesm(sArgs.proj, ...
+            'MapLatLim', latLim, ...
+            'MapLonLim', lonLim, ...
+            'Grid','on', ...
+            'Frame','on', ...
+            'LabelFormat','none', ...
+            'PLineLocation',30, ...
+            'MLineLocation',50, ...
+            'Origin',[0,0]);
+axh.YLim = latLim * pi/180;
+axh.XLim = lonLim * pi/180;
+
+% set ticks
+axh.YTick = YTicks;
+axh.YTickLabels = LatTicks;
+axh.XTick = XTicks;
+axh.XTickLabels = LonTicks;
+
+axh.YTickLabel = strcat(axh.YTickLabel, '^\circ');
+axh.XTickLabel = strcat(axh.XTickLabel, '^\circ');
+
+% set labels for x- and y-axes
+axh.YLabel.String = 'Latitude';
+axh.XLabel.String = 'Longitude';
+
+if nargout
+	varargout{1} = sArgs.fgh;
+end
+
+%end function
+end
\ No newline at end of file