Local Polynomial

The Local Polynomial gridding method assigns values to grid nodes by using a weighted least squares fit with data within the grid node's search ellipse.

 

Local Polynomial Advanced Options Dialog

In the Grid Data dialog, specify Local Polynomial as the Gridding Method and click the Advanced Options button to open the Local Polynomial Advanced Options dialog.

 

Choose a Power and Polynomial Order in the Local Polynomial Advanced Options dialog.

 

General Page

On the General page, set the Power to a number between 0 and 20, then select a Polynomial Order, 1, 2, or 3.

 

Power

Set the Power to a number between 0 and 20. The Power parameter is used to assign the power for the weighted least square function, see Local Polynomial Math. This allows data closer to the grid node to have more impact on the value of the grid node than data farther away. This parameter is similar to the Inverse Distance to a Power gridding method. 

 

Polynomial Order

Select a Polynomial Order, 1, 2, or 3.

 

1: F(X,Y) = a +bX + cY

2: F(X,Y) = a +bX + cY + dXY + eX2 + fX2

3: F(X,Y) = a +bX + cY + dXY + eX2 + fX2 +gX2Y + hXY2 + iX3 + iY3

 

Search Page

The Search page allows you to specify search rules.

 

Breaklines Page

The Breaklines page is used to add breaklines to the gridding process. Faults are not supported with Local Polynomial.

 

 

See Also

Grid Data

Local Polynomial Math

General Gridding Recommendations