Interpolates a surface from points using a trend technique.
Learn more about how Trend works
Usage tips
Command line and Scripting

As the order of the polynomial is increased, the surface being fitted becomes progressively more complex. A higherorder polynomial will not always generate the most accurate surface; it is dependent on the data.

The optional RMS file output contains information on the RMS (root mean square) error of the interpolation. This information can be used to determine the best value to use for the polynomial order, by changing the order value until you get the lowest RMS error. See How Trend works for information on the RMS file.

For the LOGISTIC option of Type of Regression, the zvalue field of input point features should have codes of zero (0) and one (1).

Some input datasets may have several points with the same X,Y coordinates. If the values of the points at the common location are the same, they are considered duplicates and have no affect on the output. If the values are different, they are considered 'coincident' points. Interpolation functions may handle this data condition differently, in some cases using the first coincident point encountered for the calculation, or sometimes the last. This may cause some locations in the output raster to have different values than what you might expect. The solution is to prepare your data by removing these coincident points.

The following environment settings affect this tool:
 General: Current Workspace, Scratch Workspace, Output Coordinate system, Output Extent, Snap Raster.
 Raster Storage: See the Raster Storage settings for the particular output raster format selected.
Map Algebra

As the order of the polynomial is increased, the surface being fitted becomes progressively more complex. A higherorder polynomial will not always generate the most accurate surface; it is dependent on the data.

The optional RMS file output contains information on the RMS (root mean square) error of the interpolation. This information can be used to determine the best value to use for the polynomial order, by changing the order value until you get the lowest RMS error.

For the LOGISTIC option, all points in the input point file and point coverage should have codes of zero (0) and one (1).

GENERATE input files in the POINT format provide an easy method to create surfaces and twodimensional coverages from ASCII files containing x,y coordinates and zvalues. The x,y coordinates and zvalues can be expressed as integers or single or doubleprecision floatingpoint values. The x,y coordinates for the output raster are stored in double precision. The zvalues are stored in single precision. GENERATE files in the POINT format contain the feature ID, x,y coordinates, and zvalues for point features. The ID values are not used by Trend. The format for GENERATE files containing points is:
ID,X,Y,Z ... END
The end of the file is indicated with the END keyword. A typical GENERATE file containing points is shown below. The file can be comma or space delimited.1,234.065,837.123,125.845 2,735.774,729.345,93.739 37,840.934,385.700,157.037 5,385.888,286.602,25.764 END

Some input datasets may have several points with the same X,Y coordinates. If the values of the points at the common location are the same, they are considered duplicates and have no affect on the output. If the values are different, they are considered 'coincident' points. Interpolation functions may handle this data condition differently, in some cases using the first coincident point encountered for the calculation, or sometimes the last. This may cause some locations in the output raster to have different values than what you might expect. The solution is to prepare your data by removing these coincident points.

Trend does not respect the Mask setting.

Learn more about how to specify the input feature dataset in the Map Algebra expression of Raster Calculator.
ArcObjects

As the order of the polynomial is increased, the surface being fitted becomes progressively more complex. A higherorder polynomial will not always generate the most accurate surface; it is dependent on the data.

The optional Output RMS file output contains information on the RMS (root mean square) error of the interpolation. This information can be used to determine the best value to use for the polynomial order, by changing the order value until you get the lowest RMS error.

For the Logistic option of trendType, all points in the input point dataset should have codes of zero (0) and one (1).

Some input datasets may have several points with the same X,Y coordinates. If the values of the points at the common location are the same, they are considered duplicates and have no affect on the output. If the values are different, they are considered 'coincident' points. Interpolation functions may handle this data condition differently, in some cases using the first coincident point encountered for the calculation, or sometimes the last. This may cause some locations in the output raster to have different values than what you might expect. The solution is to prepare your data by removing these coincident points.

The output from the ArcObjects method is a raster object.