The SPP Procedure

TREND Statement

  • TREND name = FIELD(field-definition);

The TREND statement enables you to define a spatial trend covariate, where name is a standard SAS variable name that names the trend and the FIELD suboption describes the field as follows:

FIELD (X-variable, Y-variable, field-variable )

specifies a spatial field variable as a trend by using any spatial field covariates that are available in the DATA= data set, where X-variable specifies the X coordinate and Y-variable specifies the Y coordinate of the spatial field. The third argument is the field-variable, which is a numeric variable in the DATA= data set. The X-variable and Y-variable should be the same as the ones in the PROCESS statement. If you specify a different X-variable and a different Y-variable from the ones specified in the PROCESS statement then, PROC SPP will produce an error.