lag_int

simd_kernels::kernels::window

Function lag_int 

Source 
pub fn lag_int<T: Copy + Default>(
    window: IntegerAVT<'_, T>,
    n: usize,
) -> IntegerArray<T>
Expand description

Accesses values from previous positions in integer arrays with configurable offset.

Implements SQL LAG() window function semantics, retrieving values from earlier positions in the array sequence. Essential for time series analysis, trend detection, and comparative analytics requiring access to historical data points.

§Parameters

  • window - Integer array view containing sequential data for lag access
  • n - Lag offset specifying how many positions to look backward

§Returns

Returns an IntegerArray<T> containing:

  • Values from n positions earlier in the sequence
  • Default values for positions where lag source is unavailable
  • Null mask indicating validity of lagged values

§Examples

ⓘ
use minarrow::IntegerArray;
use simd_kernels::kernels::window::lag_int;

let arr = IntegerArray::<i32>::from_slice(&[10, 20, 30, 40]);
let result = lag_int((&arr, 0, arr.len()), 1);