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Numbagg: Fast N-dimensional aggregation functions with Numba

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Fast, flexible N-dimensional array functions written with Numba and NumPy's generalized ufuncs.

Why use numbagg?

Performance

  • Outperforms pandas
    • On a single core, 2-10x faster for moving window functions, 1-2x faster for aggregation and grouping functions
    • When parallelizing with multiple cores, 4-30x faster
  • Outperforms bottleneck on multiple cores
    • On a single core, matches bottleneck
    • When parallelizing with multiple cores, 3-7x faster
  • Outperforms numpy on multiple cores
    • On a single core, matches numpy
    • When parallelizing with multiple cores, 5-15x faster
  • ...though numbagg's functions are JIT compiled, so the first run is much slower

Versatility

  • More functions (though bottleneck has some functions we don't have, and pandas' functions have many more parameters)
  • Functions work for >3 dimensions. All functions take an arbitrary axis or tuple of axes to calculate over
  • Written in numba — way less code, simple to inspect, simple to improve

Functions & benchmarks

Summary benchmark

Two benchmarks summarize numbagg's performance — the first with a 1D array of 10M elements without parallelization, and a second with a 2D array of 100x10K elements with parallelization. Numbagg's relative performance is much higher where parallelization is possible. A wider range of arrays is listed in the full set of benchmarks below.

The values in the table are numbagg's performance as a multiple of other libraries for a given shaped array calculated over the final axis. (so 1.00x means numbagg is equal, higher means numbagg is faster.)

func 1D
pandas
1D
bottleneck
1D
numpy
2D
pandas
2D
bottleneck
2D
numpy
bfill 1.06x 1.13x n/a 11.11x 5.04x n/a
ffill 1.12x 0.99x n/a 11.50x 4.25x n/a
group_nanall 1.38x n/a n/a 7.77x n/a n/a
group_nanany 1.12x n/a n/a 6.21x n/a n/a
group_nanargmax 1.16x n/a n/a 6.81x n/a n/a
group_nanargmin 1.17x n/a n/a 6.48x n/a n/a
group_nancount 1.05x n/a n/a 4.94x n/a n/a
group_nanfirst 1.52x n/a n/a 11.13x n/a n/a
group_nanlast 1.12x n/a n/a 5.56x n/a n/a
group_nanmax 1.13x n/a n/a 5.13x n/a n/a
group_nanmean 1.14x n/a n/a 5.61x n/a n/a
group_nanmin 1.12x n/a n/a 5.75x n/a n/a
group_nanprod 1.15x n/a n/a 5.25x n/a n/a
group_nanstd 1.14x n/a n/a 5.41x n/a n/a
group_nansum_of_squares 1.33x n/a n/a 8.00x n/a n/a
group_nansum 1.18x n/a n/a 5.63x n/a n/a
group_nanvar 1.13x n/a n/a 4.88x n/a n/a
move_corr 16.42x n/a n/a 115.76x n/a n/a
move_cov 12.30x n/a n/a 86.56x n/a n/a
move_exp_nancorr 6.65x n/a n/a 46.98x n/a n/a
move_exp_nancount 1.88x n/a n/a 9.95x n/a n/a
move_exp_nancov 6.53x n/a n/a 43.63x n/a n/a
move_exp_nanmean 1.61x n/a n/a 10.65x n/a n/a
move_exp_nanstd 1.76x n/a n/a 12.40x n/a n/a
move_exp_nansum 1.09x n/a n/a 9.01x n/a n/a
move_exp_nanvar 1.77x n/a n/a 11.41x n/a n/a
move_mean 6.03x 1.34x n/a 26.60x 6.25x n/a
move_std 4.76x 0.89x n/a 29.09x 6.24x n/a
move_sum 5.16x 1.13x n/a 24.02x 6.10x n/a
move_var 5.45x 1.05x n/a 29.54x 6.05x n/a
nanargmax1 2.40x 0.53x n/a 2.32x 0.93x n/a
nanargmin1 2.35x 0.50x n/a 2.53x 1.00x n/a
nancount 2.01x n/a 1.59x 12.26x n/a 3.96x
nanmax1 3.15x 0.50x 0.09x 3.59x 3.24x 0.09x
nanmean 3.00x 1.01x 3.82x 18.98x 5.04x 19.33x
nanmin1 3.07x 0.50x 0.09x 3.39x 3.03x 0.09x
nanquantile 0.69x n/a 0.53x 4.94x n/a 4.33x
nanstd 1.63x 1.61x 3.39x 12.39x 10.18x 22.03x
nansum 2.48x 0.94x 3.31x 20.47x 4.65x 17.90x
nanvar 1.61x 1.65x 3.40x 12.62x 10.49x 22.13x

Full benchmarks

func shape size ndim pandas bottleneck numpy numbagg pandas_ratio bottleneck_ratio numpy_ratio numbagg_ratio
bfill (1000,) 1000 1 0ms 0ms n/a 0ms 0.38x 0.01x n/a 1.00x
(10000000,) 10000000 1 15ms 16ms n/a 14ms 1.06x 1.13x n/a 1.00x
(100, 100000) 10000000 2 37ms 17ms n/a 3ms 11.11x 5.04x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 18ms n/a 3ms n/a 6.13x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 199ms n/a 31ms n/a 6.44x n/a 1.00x
ffill (1000,) 1000 1 0ms 0ms n/a 0ms 0.37x 0.01x n/a 1.00x
(10000000,) 10000000 1 15ms 14ms n/a 14ms 1.12x 0.99x n/a 1.00x
(100, 100000) 10000000 2 37ms 14ms n/a 3ms 11.50x 4.25x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 14ms n/a 3ms n/a 4.64x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 176ms n/a 31ms n/a 5.72x n/a 1.00x
group_nanall (1000,) 1000 1 0ms n/a n/a 0ms 0.72x n/a n/a 1.00x
(10000000,) 10000000 1 48ms n/a n/a 35ms 1.38x n/a n/a 1.00x
(100, 100000) 10000000 2 18ms n/a n/a 2ms 7.77x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
group_nanany (1000,) 1000 1 0ms n/a n/a 0ms 0.70x n/a n/a 1.00x
(10000000,) 10000000 1 49ms n/a n/a 44ms 1.12x n/a n/a 1.00x
(100, 100000) 10000000 2 18ms n/a n/a 3ms 6.21x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanargmax (1000,) 1000 1 0ms n/a n/a 0ms 1.07x n/a n/a 1.00x
(10000000,) 10000000 1 49ms n/a n/a 42ms 1.16x n/a n/a 1.00x
(100, 100000) 10000000 2 17ms n/a n/a 3ms 6.81x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanargmin (1000,) 1000 1 0ms n/a n/a 0ms 1.06x n/a n/a 1.00x
(10000000,) 10000000 1 49ms n/a n/a 42ms 1.17x n/a n/a 1.00x
(100, 100000) 10000000 2 17ms n/a n/a 3ms 6.48x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nancount (1000,) 1000 1 0ms n/a n/a 0ms 0.66x n/a n/a 1.00x
(10000000,) 10000000 1 44ms n/a n/a 42ms 1.05x n/a n/a 1.00x
(100, 100000) 10000000 2 13ms n/a n/a 3ms 4.94x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
group_nanfirst (1000,) 1000 1 0ms n/a n/a 0ms 0.73x n/a n/a 1.00x
(10000000,) 10000000 1 52ms n/a n/a 34ms 1.52x n/a n/a 1.00x
(100, 100000) 10000000 2 16ms n/a n/a 1ms 11.13x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
group_nanlast (1000,) 1000 1 0ms n/a n/a 0ms 0.72x n/a n/a 1.00x
(10000000,) 10000000 1 47ms n/a n/a 42ms 1.12x n/a n/a 1.00x
(100, 100000) 10000000 2 14ms n/a n/a 2ms 5.56x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
group_nanmax (1000,) 1000 1 0ms n/a n/a 0ms 0.71x n/a n/a 1.00x
(10000000,) 10000000 1 48ms n/a n/a 43ms 1.13x n/a n/a 1.00x
(100, 100000) 10000000 2 14ms n/a n/a 3ms 5.13x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanmean (1000,) 1000 1 0ms n/a n/a 0ms 0.72x n/a n/a 1.00x
(10000000,) 10000000 1 50ms n/a n/a 44ms 1.14x n/a n/a 1.00x
(100, 100000) 10000000 2 16ms n/a n/a 3ms 5.61x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanmin (1000,) 1000 1 0ms n/a n/a 0ms 0.73x n/a n/a 1.00x
(10000000,) 10000000 1 48ms n/a n/a 43ms 1.12x n/a n/a 1.00x
(100, 100000) 10000000 2 14ms n/a n/a 2ms 5.75x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanprod (1000,) 1000 1 0ms n/a n/a 0ms 0.70x n/a n/a 1.00x
(10000000,) 10000000 1 48ms n/a n/a 42ms 1.15x n/a n/a 1.00x
(100, 100000) 10000000 2 14ms n/a n/a 3ms 5.25x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
group_nanstd (1000,) 1000 1 0ms n/a n/a 0ms 0.71x n/a n/a 1.00x
(10000000,) 10000000 1 51ms n/a n/a 45ms 1.14x n/a n/a 1.00x
(100, 100000) 10000000 2 17ms n/a n/a 3ms 5.41x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nansum (1000,) 1000 1 0ms n/a n/a 0ms 0.74x n/a n/a 1.00x
(10000000,) 10000000 1 51ms n/a n/a 43ms 1.18x n/a n/a 1.00x
(100, 100000) 10000000 2 16ms n/a n/a 3ms 5.63x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nanvar (1000,) 1000 1 0ms n/a n/a 0ms 0.70x n/a n/a 1.00x
(10000000,) 10000000 1 51ms n/a n/a 45ms 1.13x n/a n/a 1.00x
(100, 100000) 10000000 2 16ms n/a n/a 3ms 4.88x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 2ms n/a n/a n/a 1.00x
group_nansum_of_squares (1000,) 1000 1 0ms n/a n/a 0ms 0.88x n/a n/a 1.00x
(10000000,) 10000000 1 57ms n/a n/a 43ms 1.33x n/a n/a 1.00x
(100, 100000) 10000000 2 22ms n/a n/a 3ms 8.00x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 1ms n/a n/a n/a 1.00x
move_corr (1000,) 1000 1 0ms n/a n/a 0ms 2.68x n/a n/a 1.00x
(10000000,) 10000000 1 710ms n/a n/a 43ms 16.42x n/a n/a 1.00x
(100, 100000) 10000000 2 683ms n/a n/a 6ms 115.76x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 5ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 49ms n/a n/a n/a 1.00x
move_cov (1000,) 1000 1 0ms n/a n/a 0ms 2.43x n/a n/a 1.00x
(10000000,) 10000000 1 490ms n/a n/a 40ms 12.30x n/a n/a 1.00x
(100, 100000) 10000000 2 460ms n/a n/a 5ms 86.56x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 4ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 44ms n/a n/a n/a 1.00x
move_mean (1000,) 1000 1 0ms 0ms n/a 0ms 0.46x 0.01x n/a 1.00x
(10000000,) 10000000 1 92ms 21ms n/a 15ms 6.03x 1.34x n/a 1.00x
(100, 100000) 10000000 2 88ms 21ms n/a 3ms 26.60x 6.25x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 20ms n/a 3ms n/a 6.66x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 228ms n/a 32ms n/a 7.12x n/a 1.00x
move_std (1000,) 1000 1 0ms 0ms n/a 0ms 0.53x 0.02x n/a 1.00x
(10000000,) 10000000 1 141ms 26ms n/a 30ms 4.76x 0.89x n/a 1.00x
(100, 100000) 10000000 2 123ms 26ms n/a 4ms 29.09x 6.24x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 26ms n/a 4ms n/a 7.37x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 291ms n/a 37ms n/a 7.82x n/a 1.00x
move_sum (1000,) 1000 1 0ms 0ms n/a 0ms 0.46x 0.01x n/a 1.00x
(10000000,) 10000000 1 95ms 21ms n/a 18ms 5.16x 1.13x n/a 1.00x
(100, 100000) 10000000 2 83ms 21ms n/a 3ms 24.02x 6.10x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 21ms n/a 3ms n/a 6.79x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 227ms n/a 31ms n/a 7.29x n/a 1.00x
move_var (1000,) 1000 1 0ms 0ms n/a 0ms 0.50x 0.02x n/a 1.00x
(10000000,) 10000000 1 131ms 25ms n/a 24ms 5.45x 1.05x n/a 1.00x
(100, 100000) 10000000 2 122ms 25ms n/a 4ms 29.54x 6.05x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 25ms n/a 4ms n/a 7.12x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 275ms n/a 36ms n/a 7.69x n/a 1.00x
move_exp_nancorr (1000,) 1000 1 0ms n/a n/a 0ms 2.33x n/a n/a 1.00x
(10000000,) 10000000 1 344ms n/a n/a 52ms 6.65x n/a n/a 1.00x
(100, 100000) 10000000 2 338ms n/a n/a 7ms 46.98x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 6ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 55ms n/a n/a n/a 1.00x
move_exp_nancount (1000,) 1000 1 0ms n/a n/a 0ms 0.57x n/a n/a 1.00x
(10000000,) 10000000 1 51ms n/a n/a 27ms 1.88x n/a n/a 1.00x
(100, 100000) 10000000 2 47ms n/a n/a 5ms 9.95x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 4ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 40ms n/a n/a n/a 1.00x
move_exp_nancov (1000,) 1000 1 0ms n/a n/a 0ms 2.19x n/a n/a 1.00x
(10000000,) 10000000 1 215ms n/a n/a 33ms 6.53x n/a n/a 1.00x
(100, 100000) 10000000 2 234ms n/a n/a 5ms 43.63x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 5ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 43ms n/a n/a n/a 1.00x
move_exp_nanmean (1000,) 1000 1 0ms n/a n/a 0ms 0.39x n/a n/a 1.00x
(10000000,) 10000000 1 47ms n/a n/a 30ms 1.61x n/a n/a 1.00x
(100, 100000) 10000000 2 52ms n/a n/a 5ms 10.65x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 4ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 43ms n/a n/a n/a 1.00x
move_exp_nanstd (1000,) 1000 1 0ms n/a n/a 0ms 0.68x n/a n/a 1.00x
(10000000,) 10000000 1 64ms n/a n/a 36ms 1.76x n/a n/a 1.00x
(100, 100000) 10000000 2 74ms n/a n/a 6ms 12.40x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 5ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 44ms n/a n/a n/a 1.00x
move_exp_nansum (1000,) 1000 1 0ms n/a n/a 0ms 0.38x n/a n/a 1.00x
(10000000,) 10000000 1 36ms n/a n/a 33ms 1.09x n/a n/a 1.00x
(100, 100000) 10000000 2 43ms n/a n/a 5ms 9.01x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 4ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 42ms n/a n/a n/a 1.00x
move_exp_nanvar (1000,) 1000 1 0ms n/a n/a 0ms 0.40x n/a n/a 1.00x
(10000000,) 10000000 1 56ms n/a n/a 32ms 1.77x n/a n/a 1.00x
(100, 100000) 10000000 2 64ms n/a n/a 6ms 11.41x n/a n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a n/a 4ms n/a n/a n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a n/a 46ms n/a n/a n/a 1.00x
nanargmax1 (1000,) 1000 1 0ms 0ms n/a 0ms 17.65x 0.17x n/a 1.00x
(10000000,) 10000000 1 24ms 5ms n/a 10ms 2.40x 0.53x n/a 1.00x
(100, 100000) 10000000 2 25ms 10ms n/a 11ms 2.32x 0.93x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 11ms n/a 11ms n/a 1.00x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 107ms n/a 108ms n/a 0.99x n/a 1.00x
nanargmin1 (1000,) 1000 1 0ms 0ms n/a 0ms 17.72x 0.17x n/a 1.00x
(10000000,) 10000000 1 25ms 5ms n/a 11ms 2.35x 0.50x n/a 1.00x
(100, 100000) 10000000 2 25ms 10ms n/a 10ms 2.53x 1.00x n/a 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 11ms n/a 11ms n/a 1.00x n/a 1.00x
(100, 1000, 1000) 100000000 3 n/a 108ms n/a 108ms n/a 1.00x n/a 1.00x
nancount (1000,) 1000 1 0ms n/a 0ms 0ms 0.77x n/a 0.02x 1.00x
(10000000,) 10000000 1 3ms n/a 3ms 2ms 2.01x n/a 1.59x 1.00x
(100, 100000) 10000000 2 8ms n/a 3ms 1ms 12.26x n/a 3.96x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a 3ms 1ms n/a n/a 3.97x 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a 33ms 7ms n/a n/a 5.07x 1.00x
nanmax1 (1000,) 1000 1 0ms 0ms 0ms 0ms 11.07x 0.17x 0.55x 1.00x
(10000000,) 10000000 1 32ms 5ms 1ms 10ms 3.15x 0.50x 0.09x 1.00x
(100, 100000) 10000000 2 36ms 33ms 1ms 10ms 3.59x 3.24x 0.09x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 32ms 1ms 10ms n/a 3.24x 0.10x 1.00x
(100, 1000, 1000) 100000000 3 n/a 320ms 11ms 98ms n/a 3.26x 0.11x 1.00x
nanmean (1000,) 1000 1 0ms 0ms 0ms 0ms 0.39x 0.00x 0.05x 1.00x
(10000000,) 10000000 1 17ms 6ms 21ms 6ms 3.00x 1.01x 3.82x 1.00x
(100, 100000) 10000000 2 21ms 5ms 21ms 1ms 18.98x 5.04x 19.33x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 5ms 21ms 1ms n/a 6.10x 23.77x 1.00x
(100, 1000, 1000) 100000000 3 n/a 54ms 258ms 8ms n/a 7.00x 33.59x 1.00x
nanmin1 (1000,) 1000 1 0ms 0ms 0ms 0ms 10.86x 0.17x 0.55x 1.00x
(10000000,) 10000000 1 33ms 5ms 1ms 11ms 3.07x 0.50x 0.09x 1.00x
(100, 100000) 10000000 2 36ms 32ms 1ms 11ms 3.39x 3.03x 0.09x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 32ms 1ms 10ms n/a 3.12x 0.10x 1.00x
(100, 1000, 1000) 100000000 3 n/a 320ms 11ms 102ms n/a 3.12x 0.11x 1.00x
nanquantile (1000,) 1000 1 0ms n/a 0ms 0ms 0.56x n/a 0.21x 1.00x
(10000000,) 10000000 1 114ms n/a 87ms 164ms 0.69x n/a 0.53x 1.00x
(100, 100000) 10000000 2 131ms n/a 115ms 27ms 4.94x n/a 4.33x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a n/a 315ms 19ms n/a n/a 16.51x 1.00x
(100, 1000, 1000) 100000000 3 n/a n/a 3118ms 165ms n/a n/a 18.88x 1.00x
nanstd (1000,) 1000 1 0ms 0ms 0ms 0ms 0.31x 0.02x 0.14x 1.00x
(10000000,) 10000000 1 21ms 20ms 43ms 13ms 1.63x 1.61x 3.39x 1.00x
(100, 100000) 10000000 2 24ms 20ms 43ms 2ms 12.39x 10.18x 22.03x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 20ms 46ms 1ms n/a 14.17x 32.66x 1.00x
(100, 1000, 1000) 100000000 3 n/a 202ms 513ms 13ms n/a 16.08x 40.78x 1.00x
nansum (1000,) 1000 1 0ms 0ms 0ms 0ms 0.46x 0.01x 0.03x 1.00x
(10000000,) 10000000 1 14ms 5ms 19ms 6ms 2.48x 0.94x 3.31x 1.00x
(100, 100000) 10000000 2 22ms 5ms 19ms 1ms 20.47x 4.65x 17.90x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 5ms 20ms 1ms n/a 6.21x 22.95x 1.00x
(100, 1000, 1000) 100000000 3 n/a 53ms 226ms 8ms n/a 6.98x 29.90x 1.00x
nanvar (1000,) 1000 1 0ms 0ms 0ms 0ms 0.32x 0.02x 0.13x 1.00x
(10000000,) 10000000 1 21ms 21ms 44ms 13ms 1.61x 1.65x 3.40x 1.00x
(100, 100000) 10000000 2 25ms 21ms 43ms 2ms 12.62x 10.49x 22.13x 1.00x
(10, 10, 10, 10, 1000) 10000000 5 n/a 20ms 46ms 1ms n/a 14.02x 32.28x 1.00x
(100, 1000, 1000) 100000000 3 n/a 202ms 503ms 13ms n/a 15.68x 38.98x 1.00x

2345

Example implementation

Numbagg makes it easy to write, in pure Python/NumPy, flexible aggregation functions accelerated by Numba. All the hard work is done by Numba's JIT compiler and NumPy's gufunc machinery (as wrapped by Numba).

For example, here is how we wrote nansum:

import numpy as np
from numbagg.decorators import ndreduce

@ndreduce.wrap()
def nansum(a):
    asum = 0.0
    for ai in a.flat:
        if not np.isnan(ai):
            asum += ai
    return asum

Implementation details

Numbagg includes somewhat awkward workarounds for features missing from NumPy/Numba:

  • It implements its own cache for functions wrapped by Numba's guvectorize, because that decorator is rather slow.
  • It does its own handling of array transposes to handle the axis argument in reduction functions.
  • It rewrites plain functions into gufuncs, to allow writing a traditional function while retaining the multidimensional advantages of gufuncs.

Already some of the ideas here have flowed upstream to numba (for example, an axis parameter), and we hope that others will follow.

License

3-clause BSD. Includes portions of Bottleneck, which is distributed under a Simplified BSD license.

Footnotes

  1. This function is not currently parallelized, so exhibits worse performance on parallelizable arrays. 2 3 4 5 6 7 8

  2. Benchmarks were run on a Mac M3 Max laptop in September 2024 on numbagg's HEAD, pandas 2.2.2, bottleneck 1.4.0 numpy 2.0.1, with python numbagg/test/run_benchmarks.py -- --benchmark-max-time=10. They run in CI, though GHA's low CPU count means we don't see the full benefits of parallelization.

  3. While we separate the setup and the running of the functions, pandas still needs to do some work to create its result dataframe, and numbagg does some checks in python which bottleneck does in C or doesn't do. So use benchmarks on larger arrays for our summary so we can focus on the computational speed, which doesn't asymptote away. Any contributions to improve the benchmarks are welcome.

  4. In some instances, a library won't have the exact function — for example, pandas doesn't have an equivalent move_exp_nancount function, so we use its sum function on an array of 1s. Similarly for group_nansum_of_squares, we use two separate operations.

  5. anynan & allnan are also functions in numbagg, but not listed here as they require a different benchmark setup.