( ops: ReadonlyArray<Expression>, fn: (...xs: number[]) => number | Complex, bigFn?: (...xs: BigDecimal[]) => BigDecimal | Complex | number, complexFn?: (...xs: Complex[]) => Complex )
| 131 | if (complexFn && Number.isFinite(re) && isNaNKernelResult(result)) |
| 132 | result = complexFn(ce.complex(re, 0)); |
| 133 | } |
| 134 | |
| 135 | if (result === undefined) return undefined; |
| 136 | if (result instanceof Complex) |
| 137 | return ce.number(ce._numericValue({ re: result.re, im: result.im })); |
| 138 | if (typeof result === 'number') return boxMachineNumber(ce, result); |
| 139 | return ce.number(result); |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * N-ary kernel dispatcher for special functions. |
| 144 | * |
| 145 | * Routing: |
| 146 | * - any complex operand → `complexFn` |
| 147 | * - bignum preferred and `bigFn` available → `bigFn` |
| 148 | * - otherwise → machine `fn`; if `fn` returns NaN on finite inputs and a |
| 149 | * `complexFn` is available, retry it (the value may be complex for real |
| 150 | * inputs, e.g. EllipticK(m) for m > 1). |
| 151 | * |
| 152 | * A NaN result on finite inputs yields `undefined` (the expression stays |
| 153 | * symbolic) rather than a NaN literal: the kernels use NaN to signal |
| 154 | * "outside the implemented domain", not a mathematical result. |
| 155 | */ |
| 156 | export function applyN( |
| 157 | ops: ReadonlyArray<Expression>, |
| 158 | fn: (...xs: number[]) => number | Complex, |
| 159 | bigFn?: (...xs: BigDecimal[]) => BigDecimal | Complex | number, |
| 160 | complexFn?: (...xs: Complex[]) => Complex |
| 161 | ): Expression | undefined { |
| 162 | if (!ops.every((op) => isNumber(op))) return undefined; |
| 163 | const ce = ops[0].engine; |
| 164 | |
| 165 | if (ops.some((op) => Number.isNaN(op.re) || Number.isNaN(op.im))) |
| 166 | return ce.NaN; |
| 167 | |
| 168 | let result: number | Complex | BigDecimal | undefined = undefined; |
| 169 | |
| 170 | const isNaNResult = (r: typeof result): boolean => |
| 171 | r === undefined || |
| 172 | (typeof r === 'number' |
| 173 | ? Number.isNaN(r) |
| 174 | : r instanceof Complex |
| 175 | ? r.isNaN() |
| 176 | : r.isNaN()); |
| 177 | |
| 178 | if (ops.some((op) => op.im !== 0)) { |
| 179 | result = complexFn?.(...ops.map((op) => ce.complex(op.re, op.im))); |
| 180 | } else { |
| 181 | // Cascade: bignum (if preferred) → machine → complex. A NaN from a |
| 182 | // kernel means "outside this kernel's implemented domain", so a |
| 183 | // lower-precision or complex-valued answer is better than none. |
| 184 | if (bignumPreferred(ce) && bigFn) |
| 185 | result = bigFn(...ops.map((op) => op.bignumRe ?? ce.bignum(op.re))); |
| 186 | if (isNaNResult(result)) result = fn(...ops.map((op) => op.re)); |
| 187 | if ( |
| 188 | isNaNResult(result) && |
| 189 | complexFn && |
| 190 | ops.every((op) => Number.isFinite(op.re)) |
no test coverage detected