SAGA-GIS Tool Library Documentation (v9.1.2)

Tool Field Calculator [Shapes]

The table calculator calculates a new attribute from existing attributes based on a mathematical formula. 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:
- sin(f1) * f2 + f3
- [Population] / [Area]
One can also use the drop-down-menu to append fields numbers to the formula.

If the use no-data flag is unchecked and a no-data value appears in a record's input, no calculation is performed for it and the result is set to no-data.

Following operators are available for the formula definition:

+Addition
-Subtraction
*Multiplication
/Division
abs(x)Absolute Value
mod(x, y)Returns the floating point remainder of x/y
int(x)Returns the integer part of floating point value x
sqr(x)Square
sqrt(x)Square Root
exp(x)Exponential
pow(x, y)Returns x raised to the power of y
x ^ yReturns x raised to the power of y
ln(x)Natural Logarithm
log(x)Base 10 Logarithm
pi()Returns the value of Pi
sin(x)Sine, expects radians
cos(x)Cosine, expects radians
tan(x)Tangent, expects radians
asin(x)Arcsine, returns radians
acos(x)Arccosine, returns radians
atan(x)Arctangent, returns radians
atan2(x, y)Arctangent of x/y, returns radians
min(x, y)Returns the minimum of values x and y
max(x, y)Returns the maximum of values x and y
gt(x, y)Returns true (1), if x is greater than y, else false (0)
x > yReturns true (1), if x is greater than y, else false (0)
lt(x, y)Returns true (1), if x is less than y, else false (0)
x < yReturns true (1), if x is less than y, else false (0)
eq(x, y)Returns true (1), if x equals y, else false (0)
x = yReturns true (1), if x equals y, else false (0)
and(x, y)Returns true (1), if both x and y are true (i.e. not 0)
or(x, y)Returns true (1), if at least one of both x and y is true (i.e. not 0)
ifelse(c, x, y)Returns x, if condition c is true (i.e. not 0), else y
rand_u(x, y)Random number, uniform distribution with minimum x and maximum y
rand_g(x, y)Random number, Gaussian distribution with mean x and standard deviation y
nodata()Returns tables's no-data value
isnodata(x)Returns true (1), if x is a no-data value, else false (0)

Parameters

 NameTypeIdentifierDescriptionConstraints
InputShapesShapes, inputTABLE--
OutputResult (*)Shapes, output, optionalRESULT--
OptionsResult Field (*)Table fieldFIELDSelect a field for the results. If not set a new field for the results will be added.-
Field NameTextNAME-Default: Calculation
FormulaTextFORMULA-Default: f1 + f2
Add Field to FormulaChoice, GUIFIELD_SELECTORConvenient way to append a field number to the formula. Shows one all numeric fields with number, name and datatype overview.Available Choices:
Default: 0
SelectionBooleanSELECTION-Default: 1
Use No-DataBooleanUSE_NODATA-Default: 0
(*) optional

Command-line

Usage: saga_cmd table_calculus 2 [-TABLE <str>] [-RESULT <str>] [-FIELD <str>] [-NAME <str>] [-FORMULA <str>] [-SELECTION <str>] [-USE_NODATA <str>]
  -TABLE:<str>     	Shapes
	Shapes, input
  -RESULT:<str>    	Result
	Shapes, output, optional
  -FIELD:<str>     	Result Field
	Table field
  -NAME:<str>      	Field Name
	Text
	Default: Calculation
  -FORMULA:<str>   	Formula
	Text
	Default: f1 + f2
  -SELECTION:<str> 	Selection
	Boolean
	Default: 1
  -USE_NODATA:<str>	Use No-Data
	Boolean
	Default: 0