Function th

test/compute-engine/special-functions.test.ts:1451–1452

(j: number)

    expectApprox(ce.expr(['ExpIntegralEi', -2]), -0.04890051070806112, 1e-12);
    // Ci(−2) is the PRINCIPAL value Ci(2) + iπ (ruled 2026-09-01; the
    // machine kernel used to return the real part Ci(|x|) alone).
    const cm2 = ce.expr(['CosIntegral', -2]).N();
    expect(Math.abs(cm2.re - 0.4229808287748649)).toBeLessThan(1e-12);
    expect(cm2.im).toBeCloseTo(Math.PI, 12);
  });