Monday, December 5, 2011

How to find out the digitized line directions in gvSIG

Sometimes it is useful to find out the direction the line work was digitized. It is possible to use the labeling function in gvSIG to display an indicator of the line direction as shown in the screenshot below.



The steps to label the line work with "direction" indicators are outlined below.
  1. Start gvSIG OADE 2010. Open a map view and load in a line geometry file e.g. test.shp.


  2. In the legend (TOC) pane, click the line layer. Right click the layer name with the mouse.

    A popup menu appears.
  3. Choose Properties.

    The Layer properties dialog box appears.

  4. Click  the Labeling tab.
  5. Toggle on Enable labeling. In the General field, choose Advanced settings.
  6. In the Method field, choose the Label all features in the same way.
  7. Click the Placement button.

    The Placement properties dialog box appears.

  8. In the Orientation group, choose Follow line.
     
  9. In the Position group, choose On the line. In the Orientation drop down list, choose Line.
  10. In the Along lines field, choose In the middle.
  11. Choose to Place one label per feature part. Click OK.
  12. Click the Properties button.

    The Label class properties dialog box appears.

  13. Click the first row in the Label no. grid. Then click the [...] button.

    The Expression dialog box appears.

  14. In the Expression field, type in "<". Click OK.
  15. Toggle on Label features in this class and choose All features. Click OK.
  16. Click OK.

    The digitized line directions are indicated with the "<" character.

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