Select by Attributes... (Numerical Expression)
- Author: V.Olaya (c) 2004, O.Conrad (c) 2011
- Menu: Shapes | Selection
Description
Selects records for which the expression evaluates to non-zero. The expression syntax is the same as the one for the table calculator. If an attribute field is selected, the expression evaluates only this attribute, which can be addressed with the letter 'a' in the expression formula. If no attribute is selected, attributes are addressed by the character 'f' (for 'field') followed by the field number (i.e.: f1, f2, ..., fn) or by the field name in square brackets (e.g.: [Field Name]).
Examples:
- f1 > f2
- eq([Population] * 2, [Area])
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Shapes | shapes, input | SHAPES | - | - |
| Options | Attribute | table field | FIELD | attribute to be evaluated by expression ('a'); if not set all attributes can be addressed (f1, f2, ..., fn). | - |
| Expression | text | EXPRESSION | - | Default: a > 0 |
| Use No-Data | boolean | USE_NODATA | - | Default: 0 |
| Method | choice | METHOD | - | Available Choices:
[0] new selection
[1] add to current selection
[2] select from current selection
[3] remove from current selection
Default: 0 |
Command Line
Usage: saga_cmd shapes_tools 3 [-SHAPES ] [-FIELD ] [-EXPRESSION ] [-USE_NODATA ] [-METHOD ]
-SHAPES: Shapes
shapes, input
-FIELD: Attribute
table field
-EXPRESSION: Expression
text
Default: a > 0
-USE_NODATA: Use No-Data
boolean
Default: 0
-METHOD: Method
choice
Available Choices:
[0] new selection
[1] add to current selection
[2] select from current selection
[3] remove from current selection
Default: 0