[OpendTect_Developers] help with StepInterval and extracting log values in msec

[Bruno Chaintreuil]

Dear Marcio Weck,


> I learned from Tutorial plugin how to extract well log values, but I 
> need to extract the step interval in time too [...] and I tried to 
> follow the same principle from uiExportLogs::writeLogs(StreamData & 
> sdo). [...] Am I doing this correctly? Is there another way to extract 
> the log value with time in msec?


I think you are doing it the right way. The idea is indeed to get for a 
regular depth step a time and a log value. There are different ways to 
set up the depth range along which you want to extract  the values, but 
by asking it to the well data with 
FStepIntv_->setFrom(wd.logs().dahInterval() ) you make sure it will take 
the depth range from the longest well log. The crucial step here is the 
depth to time conversion and in any case you have to work with the 
depth/time model of the well data. This is what you do with z = 
wdlist_[wID]->d2TModel()->getTime( md ). This depth/time model will 
interpolate (or extrapolate) within the depth/time table to provide you 
the best time conversion for each desired depth.


> For some wells, the time became -inf but for the most it works. I'm 
> using all the wells from F3 demo  to test.

I tried the F3 demo wells with your code and I did not have any problem. 
I would say either there is something wrong with the depths of your well 
logs or with the depth/time model itself (undefined or descending values 
which cause a bad extraction of the time in the main loop). Please check 
there are no strange values in the depth/time models of your wells (you 
can access these in the well manager by pushing the depth/time model 
button) and in your input logs.

Please contact me directly if this does not solve your problem,
Best Regards,
Bruno

-- 
 Bruno Chaintreuil, MSc.
 Software Engineer
 dGB Earth Sciences B.V.
 Nijverheidstraat 11-2, 7511 JM Enschede, The Netherlands
 bruno.chaintreuil at dgbes.com
 Tel: +31 534315155 , Fax: +31 534315104
 http://www.dgbes.com





Marcio Weck wrote:
> Dear all,
>
> My question is about extrating Log values with time in msec.
>
> I learned from Tutorial plugin how to extract well log values, but I 
> need to extract the step interval in time too. So, I looked for, how 
> OpendTect exports the Log data and I found that (quoted only the parts 
> relative to time values):
>
> /uiExportLogs::writeLogs( StreamData& sdo )
> {
> ...
>         float md = intv.atIndex( idx );
>     if ( zinft ) md *= mFromFeetFactor;
>  ...
>         else if ( inmsec ) z = wd.d2TModel()->getTime( md ) * 1000;
>  ...
> }
>
> void uiExportLogs::setDefaultRange( bool zinft )
> {
>     StepInterval<float> dahintv;
>     for ( int idx=0; idx<wd.logs().size(); idx++ )
>     {
>         const Well::Log& log = wd.logs().getLog(idx);
>         const int logsz = log.size();
>         if ( !logsz ) continue;
>
>         dahintv.setFrom( wd.logs().dahInterval() );
>         const float width = log.dah(logsz-1) - log.dah(0);
>         dahintv.step = width / (logsz-1);
>     break;
>     }
>
>     if ( zinft )
>     {
>     dahintv.start *= mToFeetFactor;
>     dahintv.stop *= mToFeetFactor;
>     dahintv.step *= mToFeetFactor;
>     }
>
>     zrangefld->setValue( dahintv );
> }
> /
>
> and I did that:
> for each well::data I create and configure a StepInterval<float> using 
> the same code from uiExportLogs::setDefaultRange( bool zinft ), and I 
> tried to follow the same principle from 
> uiExportLogs::writeLogs(StreamData & sdo).
> ps: FStepIntv is a StepInterval<float> and configured using "my 
> setDefaultRange(bool zinft)" some steps before.
>
> /std::cout << "handling logs" << std:: endl;
> const int nsteps = FStepIntv_->nrSteps();
> bool zinft = SI().depthsInFeetByDefault();
> ...
>             TypeSet<float> inplogtrc;
>             TypeSet<float> logtime;
>
>             float z =0.0, v =0.0;
>             for ( int i=0 ; i < nsteps; i++ ){
>                 float md = FStepIntv_->atIndex( i );
>                 if ( zinft ) md *= mFromFeetFactor;
>                 z = wdlist_[wID]->d2TModel()->getTime( md );
>                 v = inplog_->getValue( md );
>                 if ( mIsUdf(v) ) continue;
>                
>                 logtime.add( z*1000 ); // in msec
>                 inplogtrc.add( v );   
> ...
>
>
> // my setDefaultRange
> void setDefaultRange( bool zinft )
> {
>     delete FStepIntv_; FStepIntv_ = 0;
>     FStepIntv_ = new StepInterval<float>();
>     Well::Data& wd = *wdlist_[wID];
>     for ( int idx=0; idx<wd.logs().size(); idx++ )
>     {
>         const Well::Log& log = wd.logs().getLog(idx);
>         const int logsz = log.size();
>         if ( !logsz ) continue;
>
>         FStepIntv_->setFrom( wd.logs().dahInterval() );
>         const float width = log.dah(logsz-1) - log.dah(0);
>         FStepIntv_->step = width / (logsz-1);
>         break;
>     }
>     if ( zinft ) {
>         FStepIntv_->start *= mToFeetFactor;
>         FStepIntv_->stop *= mToFeetFactor;
>         FStepIntv_->step *= mToFeetFactor;
>     }
> }
> /
>
> For some wells, the time became -inf but for the most it works. Am I 
> doing this correctly? Is there another way to extract the log value 
> with time in msec? I'm using all the wells from F3 demo  to test.
>
> Best Regards,
>
> Márcio Weck
> ------------------------------------------------------------------------
>
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