*
   * @throws IllegalStateException if the dataset is empty
   */
  public double populationStandardDeviation() {
    return Math.sqrt(populationVariance());
  }

  /**
   * Returns the <a href="http://en.wikipedia.org/wiki/Variance#Sample_variance">unbiased sample

(Div64F x (Const64F <t> [c])) && reciprocalExact64(c) => (Mul64F x (Const64F <t> [1/c]))

// rewrite single-precision sqrt expression "float32(math.Sqrt(float64(x)))"
(Cvt64Fto32F sqrt0:(Sqrt (Cvt32Fto64F x))) && sqrt0.Uses==1 => (Sqrt32 x)

(Sqrt (Const64F [c])) && !math.IsNaN(math.Sqrt(c)) => (Const64F [math.Sqrt(c)])

// for rewriting results of some late-expanded rewrites (below)
(SelectN [0] (MakeResult x ___)) => x

    (TF_ConstOp
      (GetScalarOfType<0> $res)
    ),
    /*keep_dims=*/
    ConstBoolAttrFalse
  )>;

//===----------------------------------------------------------------------===//
// Sqrt op patterns.
//===----------------------------------------------------------------------===//

// SqrtGrad(y, dy) = dy * 0.5 / y
def LowerSqrtGradOp : Pat<
  (TF_SqrtGradOp $y, $dy),
  (TF_DivOp

		{name: "FSQRTS", argLength: 1, reg: fp11, asm: "FSQRTS", typ: "Float32"},                                                            // sqrt(arg0)
		{name: "FNEGS", argLength: 1, reg: fp11, asm: "FNEGS", typ: "Float32"},                                                              // -arg0

//
// The pattern lower FusedBatchNormV3 to arithmetic ops.
// Specifically, performs the following calculation:
//
//   (x - mean) * scale / sqrt(variance + epsilon) + offset
//
// Let multiplier = scale / sqrt(variance + epsilon),
// to compute
//   (x - mean) * scale / sqrt(variance + epsilon) + offset,
// is then to compute
//   (x * multiplier) + (offset - mean * multiplier).
//
// def : Pattern<

   * Map<String, Integer> map = ImmutableMap.of("a", 4, "b", 9);
   * Function<Integer, Double> sqrt =
   *     new Function<Integer, Double>() {
   *       public Double apply(Integer in) {
   *         return Math.sqrt((int) in);
   *       }
   *     };
   * Map<String, Double> transformed = Maps.transformValues(map, sqrt);
   * System.out.println(transformed);
   * }</pre>
   *

   * Map<String, Integer> map = ImmutableMap.of("a", 4, "b", 9);
   * Function<Integer, Double> sqrt =
   *     new Function<Integer, Double>() {
   *       public Double apply(Integer in) {
   *         return Math.sqrt((int) in);
   *       }
   *     };
   * Map<String, Double> transformed = Maps.transformValues(map, sqrt);
   * System.out.println(transformed);
   * }</pre>
   *

	}
	if i > 0 {
		var d Word
		for s := uint(0); i > 0; s += 8 {
			d |= Word(buf[i-1]) << s
			i--
		}
		z[len(z)-1] = d
	}

	return z.norm()
}

// sqrt sets z = ⌊√x⌋
func (z nat) sqrt(x nat) nat {
	if x.cmp(natOne) <= 0 {
		return z.set(x)
	}
	if alias(z, x) {
		z = nil
	}

		{name: "FSQRT", argLength: 1, reg: fp11, asm: "FSQRT"},                                          // sqrt(arg0) (floating point)
		{name: "FSQRTS", argLength: 1, reg: fp11, asm: "FSQRTS"},                                        // sqrt(arg0) (floating point, single precision)
		{name: "FFLOOR", argLength: 1, reg: fp11, asm: "FRIM"},                                          // floor(arg0), float64

   *      = ImmutableListMultimap.of("a", 4, "a", 16, "b", 9);
   * Function<Integer, Double> sqrt =
   *     new Function<Integer, Double>() {
   *       public Double apply(Integer in) {
   *         return Math.sqrt((int) in);
   *       }
   *     };
   * ListMultimap<String, Double> transformed = Multimaps.transformValues(map,
   *     sqrt);
   * System.out.println(transformed);
   * }</pre>
   *