I am working through this tutorial:
In the tutorial we import a shapefile map of railroads,clip the data through a selection/calculation to create a new layer. Next we add a new field to this new shapefile table using Field Calculator.
Everything was working until I got to steps 18 and 19 when I need to SUM up the length of all the values in the field.
I am using a later version (2.18.3) So my steps for this process are Vector>Analysis Tools>Basic Statistics for Numeric Fields.
In the Basic Statistics For Numeric Fields dialog box I am able to select the layer, but I am unable to select the field 'length_km2' I think the problem is that the field is the wrong type. The field I need is currently set to 'double' in the table. The type name is 'Real'. I think the type should be 'Real' or 'Integer'. Is there a way to edit the field type? Or is there another way to apply this calculation?