Installing Qt DataVisualization

Hey friends,

I'm currently trying to get DataVisualizations but i cant get it to work :( I tried to follow the instructions from:

http://doc.qt.io/QtDataVisualization/

i added this line to main.cpp
Code:

#include <QtDataVisualization> using namespace QtDataVisualization;
and this to the .pro file:
Code:

QT += datavisualization
i did not understand what to do with this or where to put it:
Code:

import QtDataVisualization 1.2
At the moment the general message from qt creator says this:

Warnings while parsing QML type information of /home/gordon/Qt/5.5/gcc_64/qml:
<dump of /home/gordon/Qt/5.5/gcc_64/qml>:1:24: Reading only version 1.1 parts.
<dump of /home/gordon/Qt/5.5/gcc_64/qml>:10:5: Expected only Component and ModuleApi object definitions.

Project ERROR: Unknown module(s) in QT: datavisualization
---------------

to me it seems i need to install the add on somehow, but i could not find it in the package manager. can someone point me in the right direction? is this add on included in the opensource licence?

thx in advance guys!