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+<<TableOfContents(3)>>
+====== Database ======
+===== Open a DB connection =====
+==== postgres ====
+<code>#!highlight matlab
+connection = database('mydb', 'username', 'password', 'org.postgresql.Driver', 'jdbc:postgresql://192.168.1.2:5432/my_database');
+</code>
+==== sqlite ====
+<code>#!highlight matlab
+% establish variables
+path = '/home/myhome/routes/';
+file = 'routes_20110101.sqlite';
+databaseName = ''; %leave blank
+userName = ''; %leave blank
+password = ''; %leave blank
+driver = 'org.sqlite.JDBC'; %downloaded from http://www.xerial.org/trac/Xerial/wiki/SQLiteJDBC
+databaseURL = sprintf('jdbc:sqlite:%s%s', path, file);
+% create connection
+conn = database(databaseName, userName, password, driver, databaseURL);
+% test for successful connection
+if isconnection(conn)
+% fetch data etc.
+</code>
+If you receive an exception when fetching results
+<code>
+??? Java exception occurred:
+java.lang.IllegalStateException: SQLite JDBC: inconsistent internal state
+                at org.sqlite.RS.checkCol(RS.java:69)
+                at org.sqlite.RS.getColumnCount(RS.java:423)
+Error in ==> rsmd.get at 55
+  n = 1:double(getColumnCount(d.Handle));
+Error in ==> cursor.fetch at 162
+                x = get(rs,{'ColumnName';'ColumnType'});
+</code>
+you will need to adjust the return type of the results for Matlab
+<code>#!highlight matlab
+setdbprefs('DataReturnFormat','cellarray');
+</code>
+(See the Matlab documentation for details http://www.mathworks.com/help/toolbox/database/ug/setdbprefs.html)
+===== Get Column Names =====
+<code>#!highlight matlab
+query = 'select * from blah';
+cursor = exec(connection, query);
+fetch(cursor);
+names = columnnames(cursor);
+</code>
+====== Date and Time ======
+===== Convert date to String =====
+<code>#!highlight matlab
+datestr(now, 'dd-mm-yy HH:MM:SS')
+</code>
+===== Current Date =====
+<code>#!highlight matlab
+now()
+</code>
+===== Parse a Date =====
+<code>#!highlight matlab
+str = '2010-05-03 20:30:00.0'
+datenum(str) % ans = 734261.854166667
+datevec(str) % ans =  2010           5           3          20          30           0
+</code>
+====== Figures ======
+===== Formatting =====
+==== Axis Labels ====
+<code>#!highlight matlab
+plot(time,value);
+xlabel('The Time');
+ylabel('The Value');
+</code>
+==== Date Axis ====
+<code>#!highlight matlab
+time = datenum(time_str); % convert time string to a serial number
+plot(time, value); % plot
+datetick('x', 'dd-mm-yy HH:MM:SS','keepticks'); % tell matlab to format the xaxis using the supplied date format
+</code>
+==== Legend ====
+<code>#!highlight matlab
+hold on;
+plot(x);
+plot(y);
+legend('X Values', 'Y Values');
+</code>
+===== Rectangle =====
+<code>#!highlight matlab
+rectangle('Position', [x,y, width, height], 'FaceColor','r');
+</code>
+===== Regression Line =====
+<code>#!highlight matlab
+plot(x,y, '.'); %plot data
+% plot regression line
+p=polyfit(x, y,1) % fit a polynom of degree 1
+regression_y = x* p(1)+ p(2); % if higher polynom degree is used add terms.. eg. for degree2 :   y = x.^2*p(1) + x*p(2) + p(3)
+plot(x,regression_y,'r');
+</code>
+===== Scatterplots =====
+==== Simple Scatter Plots ====
+<code>#!highlight matlab
+scatter(q, v, 'filled')  % or plot(q,v)
+</code>
+==== Scatter plot with color coding ====
+<code>#!highlight matlab
+scatter(q,v,50, relative_error,'filled') % Parameters: x,y,size of point, value to determine color
+caxis([0, 1]);
+colorbar()
+</code>
+===== Tweaks =====
+==== Disable annoying popup of plots ====
+<code>#!highlight matlab
+    set(figure,'visible','off');
+</code>
+====== Java in Matlab ======
+===== Use Java Classes from Matlab =====
+ . Long Article here: http://www.mathworks.com/access/helpdesk/help/techdoc/matlab_external/f4863.html
+Short story: there are two ways to expose java .jar files to matlab
+  * adding them to a textfile: matlab\toolbox\local\classpath.txt
+  * using the matlab command: javaaddpath
+Afterwards a java class can be used with its fully qualified name ("java.lang.String") or you can use imports ( _import java.lang.*_ or _import java.lang.String_ )
+====== NaNs ======
+===== Remove NaNs from vector =====
+<code>#!highlight matlab
+x = x(~isnan(x));
+</code>
+===== Remove rows containing NaNs from matrix =====
+<code>#!highlight matlab
+X(any(isnan(X),2),:) = [];
+</code>
+More for example here: http://www.mathworks.com/access/helpdesk/help/techdoc/data_analysis/f0-10104.html#f0-8511
+====== Sorting ======
+===== Sorting structs =====
+To sort an array of structs by one value use
+<code>#!highlight matlab
+[unused,order]  = sort({original_values(:).timestamp})
+sorted_values = original_values(order)
+</code>
+====== Webservices ======
+===== Calling a Webservice from Matlab =====
+Very simple examples can be found here: http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/createclassfromwsdl.html
+Alas, real life is never simple. I was unable to find information on how to pass an array of custom objects to a webservice. Some time of googling and trial-and-error later I finally managed to get things working. Here is an example of how to access a webservice which takes an Array of Points ( each point has x and y coordinates) and a Date as parameters:
+<code>#!highlight matlab
+% (!) Note that this is just an example on how to use a web service in Matlab.
+% There are much more convenient wrapper functions available for this specific service!
+%
+% create the inputs
+p1.x=16.38163;
+p1.y=48.18769;
+p2.x=16.35889;
+p2.y=48.18088;
+points.item=[p1 p2]; % this MUST be called "item" (sic!) or else matlab will create a wrong SOAP message!
+time.item = {'2009-05-22T12:00:00'};
+suggestions.item = {'Mit Strassenbahn'};
+% Create and call the Webservice
+createClassFromWsdl('http://10.101.21.217:8080/service?wsdl');
+efa_service=EFAService;
+getNetworkIds(server, points, time, suggestions)
+</code>

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