Tutorial 6 queues & arrays & results recording

ByMohammed Amer Al-

Batati

2012

OMNet++

Step by Step

Part - 6

cQueue is a container class that acts as a queue.The basic cQueue member functions:

insert(obj), inserts an object into the queue head. pop(), returns and removes object from the front. remove(obj), removes that object from the queue.length(), returns the number of items in the queue.empty(), tells whether there is anything in the

queue.insertBefore(obj_where, obj_what)insertAfter(obj_where, obj_what)front(), returns pointer to the object at the front. back() , returns pointer to the object at the back.

Queues

cQueue Example:

Iterators

Queues – cont.

cArray is a container class that holds objects derived from cObject. cArray works as an array, but it grows automatically when it

becomes full. The basic usage:

cArray array("array"); // Creating an array int index = array.add( obj ); // Adding an object int index = array.find(obj);// Finding an object array.remove (obj)// Remove an object

Iteration for (int i=0; i<array.size(); i++){if (array[i]) // is this position used?{

}}

Expandable Array

There are two main types of outputs: vectors and scalars.

output vectors are to record time series data and output scalars are supposed to record a single value per simulation run.

Let’s record the node power after every transmission operation. To do that add the following:1. cOutVector TxEnergy;// in Node.h2. TxEnergy.setName("NodePower");// in Node.cc (initialize())3. TxEnergy.record(energy);// after updating node energy

Save, build, and run.

Result Recording and Analysis

A folder called “results” will be generated.

Click one of VEC files to generate an analysis file (.anf).

Select “result” as parent folder -> name it-> click finish.

Output Vectors

Click Wildcard to add all other VEC files in single ANF file.

Browse data to get the following results

Output Vectors – cont.

You may want to record the distribution as a histogram (not as a time series).Syntax: cHistogram hData;hData.collect(value);// to insert a new value.

Other functions can be used to get the statics, for example: hData.getCount(), hData.getMin(),

hData.getMax(), hData.getMean(),hData.getStddev(), hData.getVariance(), hData.getSum(), hData.getSqrSum().

Histograms

Let’s record node life time, which is the time that a node takes before it dies:1. At Node.h

2. At Node.cc

Output Scalars

Save, Build and run

Play with the properties to get:

Output Scalars – cont.

An eventlog file contains a log of messages sent during the simulation and the details of events that prompted their sending or reception.

The Sequence Chart displays eventlog files in a graphical form.

Add: record-eventlog = true # In omnetpp.ini

Save and run.

Eventlog and Sequence Chart

ELOG files will be generated.

Double-Click one of them to watch the sequence chart.

Sequence Chart