Page last modified 17:03, 4 Mar 2011 by aduarte

Octave

1. Installation of Java support
1. 1.1. Linux
2. 1.2. Windows
2. Download the libraries
3. Add the SDAS libraries to the octave classpath
4. Get a connection to the sdas server
5. Search events
6. Search events in a time window
7. Search parameters
8. Search data
9. Get data

Version as of 17:24, 5 Apr 2025

Follow these steps to integrate the Shared Data Access System in your Octave code. All the examples were successfully tested in MS Windows and Linux distributions like Fedora, Gentoo and Debian. Please notice that you have to install the Octave JAVA support first. An octave FAQ on how to install packages can be found in the project's sourceforge homepage. Before installing the package, you will need to define some system variables, as explained on the next section.

The standalone MinGW32 Octave port for Windows from version 3.2.4 already includes the Java package, but it is not loaded by default and you also need to define the system variables by hand before using it. How to load a package is explained on this FAQ.

Installation of Java support

You should use the last version (at least 1.5) of the Sun Java Development Kit (JDK).
First you have to find out where is your java home located. To avoid errors, download and run this utility. The value returned by the utility is the JAVA_JRE value.

Now you have to set JAVA_HOME as a system variable:

Linux

Supposing you have the JAVA_JRE in /opt/jdk1.6.0_18/jre:

export JAVA_HOME="/opt/jdk1.6.0_18/"

Windows

Open the windows System Properties (right - click on My Computer or go to the Control Panel)

Select the tab Advanced
Click on Environment Variables...
In the system variables click New...
The Variable name is: JAVA_HOME
In the value field (supposing the value of JAVA_JRE is C:\java\jdk1.6.0_18\jre) enter the following value: C:\java\jdk1.6.0_18

Attention: if the path to your installation of Java contains spaces, it needs to be written between quotation marks (").

In MS Windows you need to define two more system variables:

JAVA_INCS: create this system variable with directives for the java compiler to include the header files that come with JDK (switch \ with /). Using the example above, the value of JAVA_INCS would be:

-IC:/java/jdk1.6.0_18/include -IC:/java/jdk1.6.0_18/include/win32

Add JAVA_HOME\bin to the existing PATH system variable. Following the examples above, you must add:
```
C:\java\jdk1.6.0_18\bin
```

Download the libraries

Download the following libraries into a folder of your system:

Apache XML-RPC
Apache Jakarta Commons
SDAS Core Libraries
SDAS Client

Since the server at baco computer uses an older version, if you are planing on accessing it server, you should download this version of SDAS Core Libraries and Client:

SDAS Core Libraries
SDAS Client

Add the SDAS libraries to the octave classpath

These example assume that you have saved all the jar files in the folder /home/user/sdas/

javaaddpath("/home/user/sdas/SDAS.jar")
javaaddpath("/home/user/sdas/SDASClient.jar")
javaaddpath("/home/user/sdas/commons-codec-1.3.jar")
javaaddpath("/home/user/sdas/xmlrpc-2.0.jar")

Beware that on Windows you must use / instead of the regular \. If you have saved all the jar files in the folder C:\sdas\, for example:

javaaddpath("C:/sdas/SDAS.jar")
javaaddpath("C:/sdas/SDASClient.jar")
javaaddpath("C:/sdas/commons-codec-1.3.jar")
javaaddpath("C:/sdas/xmlrpc-2.0.jar")

Get a connection to the sdas server

client = java_new("org.sdas.core.client.SDASClient", "baco.ipfn.ist.utl.pt", 8888);

Search events

found = client.searchDeclaredEventsByName('S');

found = client.searchDeclaredEventsByName('S');

found = client.searchDeclaredEventsByName('SHOT', 'en');

found = client.searchDeclaredEventsByUniqueID('SHOT', 'en');

found = client.searchDeclaredEventsByDescription('SHOT');

found = client.searchDeclaredEventsByDescription('SHOT', 'en');

for i=1:1:size(found)
    found(i).toString
end

max = client.searchMaxEventNumber('0x0000')

min = client.searchMinEventNumber('0x0000')

Search events in a time window

NOTE: You can construct time with a resolution of picosseconds, just add to the example values for millis, micros, nanos and picos
NOTE 2: Date constructors have the months index to 0 (January is 0 and December is 11)

Search events in December 2005:

date_start = java_new("org.sdas.core.time.Date", 2005, 11, 1);
date_end =  java_new("org.sdas.core.time.Date", 2005, 11, 31);
tstart =  java_new("org.sdas.core.time.TimeStamp", date_start);
tend =  java_new("org.sdas.core.time.TimeStamp", date_end);
eventsFound = client.searchEventsByEventTimeWindow(tstart, tend);
for i = 1:1:size(eventsFound)
    eventsFound(i).toString
end

Search events in the 22 December 2005 between 5pm and 6pm:

date_start = java_new("org.sdas.core.time.Date", 2005, 11, 22);
date_end = java_new("org.sdas.core.time.Date", 2005,11,22);
time_start = java_new("org.sdas.core.time.Time", 17, 0, 0);
time_end = java_new("org.sdas.core.time.Time", 18, 0, 0);
tstart = java_new("org.sdas.core.time.TimeStamp", date_start, time_start);
tend = java_new("org.sdas.core.time.TimeStamp", date_end, time_end);
eventsFound = client.searchEventsByEventTimeWindow(tstart, tend);
for i = 1:1:size(eventsFound)
    eventsFound(i).toString
end

Search parameters

parametersFound = client.searchParametersByName('DENS');

parametersFound = client.searchParametersByName('DENS', 'pt');

parametersFound = client.searchParametersByUniqueID('DENS');

parametersFound = client.searchParametersByDescription('current');


for i = 1:1:size(parametersFound)
    parametersFound(i).toString
end

Search data

This function returns the parameters unique identifiers where the data isn’t null for the selected event:

dataFound = client.searchDataByEvent('0x0000', 17898);
for i = 1:1:size(dataFound)
    dataFound (i)
end

Get data

NOTE: The unique identifiers are CASE-SENSITIVE

NOTE2: Some java types like float and long are not automatically recognised by octave. A transformation must be manually performed using the intValue and doubleValue methods

The returned data structure gives you information about:

start time
end time
time of the event
mime_type
the parameter unique identifier

Data for only one parameter

dataStructArray=client.getData('POST.PROCESSED.DENSITY','0x0000', 17898)
dataStruct=dataStructArray(1);
dens=dataStruct.getData;
for i=1:length(dens)
density(i)=dens(i).doubleValue;
end
tstart = dataStruct.getTStart;
tend = dataStruct.getTEnd;

Calculate the time between samples

tbs= (tend.getTimeInMicros.intValue - tstart.getTimeInMicros.intValue)/length(density);

Get the events associated with this data

events = dataStruct.getEvents;

The event time (I’m assuming the event I want is at the index 0, but I should check first...)

tevent = events(1).getTimeStamp;

The delay of the start time relative to the event time

delay = tstart.getTimeInMicros.intValue - tevent.getTimeInMicros.intValue

Finally create the time array

times = delay:tbs:delay+tbs*(length(density)-1);

And plot the data

plot(times, density);

Data for several parameters in the same event

dataStruct=client.getMultipleData({'POST.PROCESSED.DENSITY', 'POST.PROCESSED.IPLASMA'},'0x0000', 17898)
dataStructDens=dataStruct(1,1);
dataStructIP=dataStruct(2,1);
dens=dataStructDens.getData(); 
ip=dataStructIP.getData();

Data for several parameters in different events

dataStruct=client.getMultipleData({'POST.PROCESSED.DENSITY', 'POST.PROCESSED.IPLASMA'},{'0x0000','0x0000'}, [17898,17899])
dataStructDens=dataStruct(1,1);
dataStructIP=dataStruct(2,1);
dens=dataStructDens.getData(); 
ip=dataStructIP.getData();

Data for the same parameter in different events

dataStruct=client.getMultipleData('POST.PROCESSED.DENSITY',{'0x0000','0x0000'}, [17898,17899])
dataStructDens=dataStruct(1,1);
dataStructIP=dataStruct(2,1);
dens=dataStructDens.getData(); 
ip=dataStructIP.getData();

Data for the same parameter in different event numbers

dataStruct=client.getMultipleData('POST.PROCESSED.DENSITY', '0x0000', [17898,17899])