The Sample Selection tool is used to select
samples from a vector layer to train classification algorithms. It allows to select some
geometries in the layer and to assign classes to them.
Using the interface
It is accessed through:
GeoDMA >
Select Samples
To select samples from a layer, perform the following:
-
In the Input Parameters group:
-
Vector Layer: select the layer
where the samples will be selected.
-
Label Column: select or create the
column where the samples will be saved. If you want to create a new column,
click
.
In the Dialog opened, type the name of the column to be created.
NOTE: The column name can not contain any
special character (Spaces, accents, etc).
-
If the column selected in the Label Column
combo box already exists, a dialog will be shown asking to load the existing samples. If
you click Yes, the samples existing in the column will be loaded and you can
edit/delete them or add more samples. If you click No, the samples will not be
loaded and the selected samples will overwrite the existing column.
-
In the Add New Class group:
-
Label: Type the name of the new
class.
-
Select the color of the new class. NOTE:
The color selected is only for visualization. It will not be saved.
-
Click
to add the new class.
-
In the Sample Set and
Tools groups:
-
The existent classes will be shown in the pane bellow the
Sample Set group name.
-
To select new samples from a class, select the class in the pane and ensure
that the selection tool
is
activated in the window. NOTE:
This selection tool is different from the default TerraView selection tool.
Thus, you MUST use it.
-
In the TerraView Map Display, select the geometries corresponding to the desired
class. The selected geometries will be colored with the class color.
-
To add the selected samples to the selected class, click
in
the Tools group. The added samples will be colored in the Map Display
with transparency, in the color of the class.
-
To save the added samples in the data source (layer selected in the
Vector Layer combo box), click
in the Tools group. The samples added, but not saved in the data source
will appear with Bold and Italic font in the Classes pane. The
saved samples will appear in normal font.
-
To delete an added samples, select them in the Map Dislpay or in the Classes pane
and click
.
If a class is selected, it will delete the class and all its samples.
-
In the Output group:
-
CSV File (Optional): If you want to export the samples and data as CSV, select a
CSV file by clicking in
.
-
Click OK to close and save the samples or Cancel to close the
interface without saving. NOTE: The samples
saved through the button
will not be removed if you click Cancel.