NEED HELP: GSL with QWT

[t.v.zolkin]

Hi All. I'm new with qwt library, and now I'm having big troubles with next problem:
I have a gsl_matrix *My_matrix object, and realy haven't idea and understanding how plot it...(I need something like Scatter plot screenshot in qwt web site from my gsl_matrix).
How I have read firstly I need to create a QwtPlot *My_Plot and QwtPlotCurve *My_Curve objects. And after that I must set data into the curve...But If I right understand curve have two ways of data settings:
1) setRawData (const double * xData, const double *yData, int size)
And i dont understand what this function mean (is xData just simple value (and if its true how set array of data) or xData is array, and in this case I don't understand how transfer data from my gsl_matrix here (probably it is possible wiyh using matrix_view but I dont know how))
2) using setData(const double *xData, const double *yData, int size) which is also not simple for me cause I'have not idea how...

Please explain me how deside my problem. TIA

[Uwe]

The only way to connect values to a curve is to use a QwtData object. All other QwtPlotCurve::setData() methods are convenience functions, that create an internal QwtData object.

So subclass QwtData and implement the virtual methods as a bridge to your matrix. Note that YourData::copy() only needs to copy the bridge - not the matrix itsself.

Uwe

[t.v.zolkin]

Are you mean that I need doing something like that:

QwtData *My_data = new QwtData();
My_data -> copy( My_gsl_matrix);

??? sorry about misunderstuding?

[Uwe]

QwtData is an interface only - the functionality behind is implemented in derived classes. ( like QAbstractItemModel ). If you don't know the concept of abstract interfaces please have a look in your OO bible.

Uwe