repl.txt (1192B)
1 2 {{alias}}() 3 Returns an accumulator function which incrementally computes a product. 4 5 If provided a value, the accumulator function returns an updated product. If 6 not provided a value, the accumulator function returns the current product. 7 8 If provided `NaN` or a value which, when used in computations, results in 9 `NaN`, the accumulated value is `NaN` for all future invocations. 10 11 For long running accumulations or accumulations of large numbers, care 12 should be taken to prevent overflow. Note, however, that overflow/underflow 13 may be transient, as the accumulator does not use a double-precision 14 floating-point number to store an accumulated product. Instead, the 15 accumulator splits an accumulated product into a normalized fraction and 16 exponent and updates each component separately. Doing so guards against a 17 loss in precision. 18 19 Returns 20 ------- 21 acc: Function 22 Accumulator function. 23 24 Examples 25 -------- 26 > var accumulator = {{alias}}(); 27 > var v = accumulator() 28 null 29 > v = accumulator( 2.0 ) 30 2.0 31 > v = accumulator( -5.0 ) 32 -10.0 33 > v = accumulator() 34 -10.0 35 36 See Also 37 -------- 38