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Stats

Stats with float/double and a narrower int/short/long family. uint is excluded: an unsigned type has no signed-overflow-safe range reduction.

Whole-array & per-axis reductions

Whole-array (floatN, or a floatMxN treated flat): sum, mean, variance/varianceSample, stdDev/stdDevSample, argmin/argmax, min/max, median, range, plus two bundled-result shortcuts that compute several of the above together in as few passes as possible: meanMinMaxRange(x) and the full-summary bundle meanMinMaxRange_medianIQRstdDevVariance(x).

Per-axis, each with a ref floatN dest zero-alloc form and an allocating form: rowSum/colSum, rowMean/colMean, rowMin/rowMax/colMin/colMax, rowVariance/colVariance, rowStdDev/colStdDev, rowNormL1/rowNormL2/colNormL1/colNormL2.

Covariance & correlation

covarianceInto(in A, ref C) / covariance(in A) / correlation(in A) - computed via Gram formulation (center once, then centeredᵀ · centered through Blas's matMatDotTransA). Degrades to a zero matrix (not NaN) when M < 2 for the ref-dest primitive; allocating wrappers throw.

Transforms

Whole-array and per-axis (Rows/Columns) in-place variants of standardize, rescale (+ (lo,hi) overload), center, maxAbs, softmax.

Integer stats - widened-return convention

sum → long (overflow headroom); mean/variance/stdDev/varianceSample/stdDevSample/median → double (need a fractional result); min/max → int (same type); argmin/argmax → int (index). Whole-array only - no per-axis reductions, covariance, or in-place transforms for the integer family.

Histogram & resampling

Two smaller features that live alongside Stats:

  • Histogram - histogramInto(in data, lo, hi, ref Indices counts) (+ auto-range overload), densityInto, cdfInto (monotone, last bin pinned to 1.0), histogram2DInto. Out-of-range and NaN samples are always dropped, never thrown (the closed upper edge x == hi lands in the last bin, not dropped). ref-dest only, no allocating wrapper.
  • Resample - sampleAt(in data, float pos, Interp, EdgeMode) : float (continuous-position evaluation: Nearest/Linear/Cubic Catmull-Rom over 4 taps), resampleInto (1D endpoint- preserving resize, point-resampling, no anti-alias prefilter), resample2DInto (separable 2-pass). EdgeMode{Clamp, Wrap, Mirror}.