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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">You can find higher-level widgets like this in CTK. For example,
<a href="http://www.commontk.org/index.php/Documentation/ctkTransferFunctionWidget">
http://www.commontk.org/index.php/Documentation/ctkTransferFunctionWidget</a>.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Andras<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> vtkusers [mailto:vtkusers-bounces@vtk.org]
<b>On Behalf Of </b>David Gobbi<br>
<b>Sent:</b> Wednesday, September 20, 2017 11:15 AM<br>
<b>To:</b> Miguel Nunes <m.nunes@fratoria.com><br>
<b>Cc:</b> VTK Users <vtkusers@vtk.org><br>
<b>Subject:</b> Re: [vtkusers] A simple and efficient histogram class?<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hi Miguel,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I think you listed all the histogram classes. The simplest is vtkImageHistogram, e.g.<o:p></o:p></p>
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<p class="MsoNormal"><a href="https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.kitware.com%2Fvtk%2Fvtk%2Fblob%2Fmaster%2FImaging%2FCore%2FTesting%2FCxx%2FImageHistogram.cxx&data=02%7C01%7Classo%40queensu.ca%7C43231217f85e4232906508d5003a63e4%7Cd61ecb3b38b142d582c4efb2838b925c%7C1%7C0%7C636415173137430197&sdata=bLPacE94PkaGB7%2B%2Bhx8MZnEuBCE9OizpRTN7zzN9qig%3D&reserved=0" target="_blank">https://gitlab.kitware.com/vtk/vtk/blob/master/Imaging/Core/Testing/Cxx/ImageHistogram.cxx</a><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Rather than producing a plot, per se, it produces the histogram as an image. It's basic interface is:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">SetNumberOfBins(15)<o:p></o:p></p>
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<p class="MsoNormal">SetBinSpacing(1.0)<o:p></o:p></p>
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<p class="MsoNormal">SetBinOrigin(0.0)<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">So you would need to compute the "BinSpacing" from your desired range. The "BinOrigin" is simply the lower end of the range.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">As well as producing an image of the histogram, it has a GetHistogram() method for getting the histogram as an array.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"> - David<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, Sep 20, 2017 at 8:09 AM, Miguel Nunes <<a href="mailto:m.nunes@fratoria.com" target="_blank">m.nunes@fratoria.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Hello,<br>
I would like to ask this list about histograms in VTK c++. I have been a vtk<br>
user for several years, but never had the need to use histograms through vtk<br>
as I was using pure c++ and openGL.<br>
Now, I would like to simply plot a basic histogram of a float 3d image. I<br>
have taken a look at the examples provided but I find myself quite confused.<br>
Honestly, for an advanced visualization toolkit I am quite surprised to find<br>
it so complicated. There are classes such as vtkPlot that allow bars, then<br>
there is vtkBarChartActor, vtkImageAccumulate, vtkXYPlotActor,<br>
vtkImageHistogramStatistics and vtkImageHistogram.<br>
<br>
It all needs to be remixed, connected and many properties have to be set<br>
manually.<br>
<br>
Maybe I am missing a class (or the point), but in general terms I would like<br>
to easily plot and render a simple histogram, like:<br>
<br>
myHistogram->setData( vtkImagaData *)<br>
myHistogram->setXRange(range[2]) // clips values under and above the range specified<br>
myHistogram->setNumberOfBins(15) // calculates the bin width and each bins' Y<br>
myHistogram->update() //generate the whole thing<br>
renderer->getActor()->setData(myHistogram)<br>
<br>
...and then its done.<br>
<br>
Any chance this actually exist? Thank you very much!<o:p></o:p></p>
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