Looking for global trends
To identify a global trend in your data, look for a curve that is not flat on the projected plane.
If you have a global trend in your data, you may want to create a surface using one of the deterministic interpolation methods (for example, global or local polynomial), or you may wish to remove the trend when using kriging.
Etapes :
- Click the point or polygon feature layer in the ArcMap table of contents that you want to explore.
- Click the Geostatistical Analyst drop-down menu on the Geostatistical Analyst toolbar, click Explore Data, then click Trend Analysis.
- On the Trend Analysis interface, click the Trend and Projections choice under the Graph Options.
- Explore the bold lines on the vertical walls of the graph. These lines are indicating trends. One trend line goes along the x-axis (typically showing the longitudinal trend), while the other one shows the trend along the y-axis (typically the latitudinal trend). It is very useful to change the Order of Polynomial while examining the trends.
Astuce :
It can be very helpful to check for trends in directions that vary from the standard N–S and E–W. To enable such a view, rotate the trend axes by scrolling the upper wheel on the right-hand side of the tool, just under the main display window.
Rubriques connexes
7/10/2012