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Unable to access predictions in some tools in canvas

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Unable to access predictions in some tools in canvas

Postby PenguinJunk » Fri Jun 28, 2013 12:19

I've set up a simple linear regression in Orange Canvas. My data passes through the Data Sampler to produce a training and a validation set. The training set is sent to Linear Regression and the predictor from this to the Predictions tool. The validation set is also sent to the Predictions tool.

In the Predictions tool, I can see the predictions and all looks well. I can also see the predictions if I send them to Data Table and I can see that they exist if i send the data to Merge Data. I would like to plot the actual against the predicted values and look at the distribution of the error. However, if I send my predictions to Scatterplot, I can only see my input attributes and the validation values (not the predictions). The same is true if I send my predictions to Feature Constructor. Sending them via Data Table or Merge Data does not help.

Please can you tell me where i am going wrong? I don't want to have to export the predictions and do the analysis in another tool.

Re: Unable to access predictions in some tools in canvas

Postby Ales » Fri Jun 28, 2013 12:30

The predictions are added as a meta attribute, which the Scatter Plot (and some other widget) do not use.

To work around this add a 'Select Attributes' widget after the 'Predictions' widget and move the meta attribute corresponding to the prediction column to regular attributes.

Re: Unable to access predictions in some tools in canvas

Postby PenguinJunk » Fri Jun 28, 2013 12:33

Thank you, I just discovered that as you replied. Thank you for your fast response. Is there a reason why they become meta attributes?


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