Operators and parameters in expressions | Prediktera Documentation

Operators than can be used expressions include the data operators wNNN and bMMM for referring to wavelength bands, the range operator : used for averaging data, standard arithmetic (+,-,/,* …) and comparison operators (=,>,< …) as well as some mathematical functions ( …) and constants ( ).

Breeze does not validate the provided expression until you click Apply changes to apply it to some data.

Data Operator	Description
`wNNN`	Wavelength lookup operator that finds the wavelength band closest to the provided number `NNN`. This means `NNN` need not match exactly to find data. A setting controls how far off a wavelength is allowed to be to be considered a match. If there isn’t matching data an error is displayed when applying the workflow to data. Learn more in Wavelength matching. Example of this syntax: `w700` or `w1714`.
`bMMM`	Band index operator. `MMM` represent the one-based index of a wavelength band. For example `b1` is the first band, and `b20` is the twentieth. If the index `MMM` does not exist, Breeze displays an error message.
`:`	Average range operator that returns the average value for a range of wavelength bands. For example: `w1200:w1500` yields average value of all data points between wavelength 1200 nm and 1500 nm. `b1:b2` yields average values of the first two bands.

Data Operator

Description

wNNN

Wavelength lookup operator that finds the wavelength band closest to the provided number NNN. This means NNN need not match exactly to find data.

A setting controls how far off a wavelength is allowed to be to be considered a match. If there isn’t matching data an error is displayed when applying the workflow to data. Learn more in Wavelength matching.

Example of this syntax: w700 or w1714.

bMMM

Band index operator. MMM represent the one-based index of a wavelength band. For example b1 is the first band, and b20 is the twentieth.

If the index MMM does not exist, Breeze displays an error message.

:

Average range operator that returns the average value for a range of wavelength bands.

For example: w1200:w1500 yields average value of all data points between wavelength 1200 nm and 1500 nm. b1:b2 yields average values of the first two bands.

Expand to see all available operators

Arithmetic Operator	Description
`-`	Subtract
`+`	Add
`/`	Divide
`*`	Multiply
`%`	Modulo
`^`	Raised to a power

Comparison Operator	Description
`=`	Equal to
`\|` `OR`	TRUE if any of the conditions separated by OR is TRUE
`&` `AND`	TRUE if all the conditions separated by AND is TRUE
`!=` `<>`	Not equal to
`<`	Less than
`<=`	Less than or equal to
`>`	Greater than
`>=`	Greater than or equal to

Function operator	Description
`SQRT(N)`
`SIN(N)`
`COS(N)`
`EXP(N)`
`LOG(N)`
`LOG10(N)`
`AVG(N)`
`ROUND(N)`

Constants	Description
`TRUE`	Always evaluates to TRUE
`FALSE`	Always evaluates to FALSE
`INF`	token value
`PI`	approximated to