Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
introgis [2017/11/22 16:23]
qcbs [Exercise 5 - Manipulation of rasters and intro to satellite imagery]
introgis [2017/11/24 10:54] (current)
qcbs [Exercice 3 - Interpolation and raster manipulation with QGIS]
Line 208: Line 208:
 **Step 8**: From the menu 'Layer properties'​ of the table '​BBS_Routes_QC.shp',​ find the Join tab and join the table BBS_Routes and BBS_Ovenbird_QC using the shared column '​Route'​ (select Route as both the source and the target columns). Disable the option to "Cache join layer in virtual memory"​. You should now see the number of ovenbird observations per year in the attribute table of the '​BBS_Routes_QC'​ file.  **Step 8**: From the menu 'Layer properties'​ of the table '​BBS_Routes_QC.shp',​ find the Join tab and join the table BBS_Routes and BBS_Ovenbird_QC using the shared column '​Route'​ (select Route as both the source and the target columns). Disable the option to "Cache join layer in virtual memory"​. You should now see the number of ovenbird observations per year in the attribute table of the '​BBS_Routes_QC'​ file. 
  
-**Step 9**: Activate the editing mode and use the 'Field Calculator'​ to add a new column (real, precision 2) to the table BBS_Routes containing the sum of the number of bird observations between 1980-1994 and 1995-2010. Each field has to be selected one by one from the Fields and Values list (sorry). The data type should be integer (length 10 or more). Column names should have less than 10 characters, should start with a letter and should contain no spaces or special characters.+**Step 9**: Activate the editing mode and use the 'Field Calculator'​ to add a new column (real, precision 2) to the table BBS_Routes containing the sum of the number of bird observations between 1980-1994 and 1995-2010. Each field has to be selected one by one from the Fields and Values list (sorry). Column names should have less than 10 characters, should start with a letter and should contain no spaces or special characters.
  
 **Step 10**: Save the changes and exit editing mode. Note that only the new columns that were created are really part of the BBS_Routes_QC table. Now remove the join (from the Properties menu) to remove the yearly observations. If you see a series of NULL values in the newly computed columns, close the attribute table and open it again. ​ **Step 10**: Save the changes and exit editing mode. Note that only the new columns that were created are really part of the BBS_Routes_QC table. Now remove the join (from the Properties menu) to remove the yearly observations. If you see a series of NULL values in the newly computed columns, close the attribute table and open it again. ​