LinearFilter Command

Use the LinearFilter command in a Logic Template to filter out records that lie within a linear range.

When dealing with large amounts of data it is often more efficient to use a range index to narrow the search. The LinearFilter command can then be used to fine tune the result set.

To execute a Linear Filter request, use the LinearFilter command with three or four arguments:

LinearFilter( bd, dat, rng ); or LinearFilter( bd, dat, rng, flag );

LinearFilter Arguments

Argument

Description

bd

Indicates how the boundaries of the range are handled.

dat

The name of the data field to be tested.

rng

The name of the HTML variable containing the range used for filtering.

flag

Indicate ( drop or keep ) special processing for records with a value of zero for dat.

Access the LinearFilter Dialog Box by selecting Numeric->Linear menu item under the Filtering category of the Logic Template editor command menu.

Examples

Command

Description

Range = [ LowLimit :: HiLimit ];

LinearFilter( INCLUSIVE_LOW, DataValue, Range);

Pass records containing, in the field named "DataValue", a value that is greater than or equal to the value stored in HTML variable "LowLimit" and less than the value stored in the HTML variable "HiLimit".

LinearFilter( INCLUSIVE_LOW, DataValue, Range, keep);

Pass records containing, in the field named "DataValue", 0 or a value that is greater than or equal to the lower limit and less than the upper limit of a range returned from the HTML selection list named "Range".

Range = [ LowLimit :: HiLimit ];

LinearFilter( INCLUSIVE, DataValue, Range);

Pass records containing, in the field named "DataValue", a value that is greater than or equal to the value stored in HTML variable "LowLimit" and less than or equal to the value stored in the HTML variable "HiLimit".

LinearFilter( INCLUSIVE, DataValue, Range, keep);

Pass records containing, in the field named "DataValue", 0 or a value that is greater than or equal to the lower limit and less than or equal to the upper limit of a range returned from the HTML selection list named "Range".

LinearFilter( NONINCLUSIVE, DataValue, Range);

Pass records containing, in the field named "DataValue", a value that is greater than the lower limit and less than the upper limit of a range returned from the HTML selection list named "Range".

Range = [ LowLimit :: HiLimit ];

LinearFilter( NONINCLUSIVE, DataValue, Range, keep);

Pass records containing, in the field named "DataValue", 0 or a value that is greater than the value stored in HTML variable "LowLimit" and less than the value stored in the HTML variable "HiLimit".

LinearFilter( INCLUSIVE_HIGH, DataValue, Range);

Pass records containing, in the field named "DataValue", a value that is greater than the lower limit and less than or equal to the upper limit of a range returned from the HTML selection list named "Range".

Range = [ LowLimit :: HiLimit ];

LinearFilter( INCLUSIVE_HIGH, DataValue, Range, keep);

Pass records containing, in the field named "DataValue", 0 or a value that is greater than the value stored in HTML variable, "LowLimit" and less than or equal to the value stored in the HTML variable, "HiLimit".