Resources Numerical accuracy

Calculations

Every calculation under our calculation policies: what it works out, its formula and the precision it runs at. Open one to see its code as it is in the released app.

  • 6,917 calculations in 1,248 source files
  • 143 exact
  • 6,286 in 64-bit
  • 335 with a 32-bit step
  • Last reviewed

Calculations

  • Permeability of free space

    The constant μ0 used in every hand formula.

    μ0 = 4 × 10⁻⁷ × π

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Round conductor as a polygon

    The corners of the polygon that stands for a round wire.

    pᵢ = (cx + r cos(2πi ÷ n), cy + r sin(2πi ÷ n)), n = 48

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • C-core gap field

    The flux density in the air gap of a C-core electromagnet by the magnetic circuit formula.

    B = μ0 × NI ÷ ((g + l ÷ μr) × 10⁻³), l = 2(w − tk) + 2(h − tk) − g

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Magnet in a closed iron frame

    The flux density in a permanent magnet set in one leg of a closed frame.

    B = Br × (lm ÷ μrm) ÷ (lm ÷ μrm + L ÷ μr), L = 2(w − tk) + 2(h − tk) − lm

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Field round one wire

    The flux density at two radii from the center of a round conductor.

    B = μ0 × I ÷ (2π × r × 10⁻³), r = 2a

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Force between two wires

    The force per meter between two parallel conductors.

    F = μ0 × |I₁ × I₂| ÷ (2π × d × 10⁻³)

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Template sizes within their ranges

    Clamps each size a person types to the template's allowed range.

    Magnetics add-on: template shapes and hand formulas addons/magnetics/lib/templates.js
    • PartCraft
    64-bit
  • Frame of the study's plane

    The origin and axes of the plane the result is drawn in.

    x = (helper × n) ÷ |helper × n|; y = n × x

    Magnetics add-on: the result drawn as display bodies addons/magnetics/lib/bodies.js
    • PartCraft
    32-bit, display only
  • Triangle cut to the crop rectangle

    Cuts a field triangle to the rectangle that is shown.

    Magnetics add-on: the result drawn as display bodies addons/magnetics/lib/bodies.js
    • PartCraft
    32-bit, display only
  • Field color bands

    The color band each triangle falls in.

    band = min(9, floor(|B| ÷ top × 10))

    Magnetics add-on: the result drawn as display bodies addons/magnetics/lib/bodies.js
    • PartCraft
    32-bit, display only
  • Defining constants

    The pound, standard gravity, inch and foot, and the pound-force, gallon and British thermal unit built from them.

    lbf = 0.45359237 × 9.80665; gal = 231 × 0.0254³; BTU = 1055.05585262 J

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    Exact
  • Unit table

    Each unit's factor to SI and its dimension.

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    Exact
  • SI prefixes

    A prefixed unit such as kPa or mm from its base unit.

    factor = prefix × unit factor

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Combining units

    The factor and dimension of a product or quotient of two units.

    f = f_a × f_bᵉ; dimension = d_a + e × d_b

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Reading a unit text

    Turns a text such as W/(m^2 K) into one factor and one dimension.

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Value to SI

    A value in a given unit as its SI value.

    SI = v × f

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Value from SI

    An SI value in a given unit.

    v = SI ÷ f

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Unit to unit

    A value converted from one unit to another of the same kind.

    result = v × f_from ÷ f_to

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Temperature points

    Celsius and Fahrenheit readings to and from kelvin.

    K = °C + 273.15; K = (°F − 32) × 5 ÷ 9 + 273.15

    Engineering units: factors, dimensions and conversion engineer/eng-units.js
    • PartCraft
    64-bit
  • Power and logarithm used

    Which power and logarithm functions the curves are evaluated with.

    Material packs: property curves by temperature engineer/material-pack.js
    • PartCraft
    64-bit
  • One curve segment

    The fitted curve's value at a temperature.

    y = 10^(Σ cᵢ Lⁱ), L = log10 T; or y = c₀ + T(c₁ + T(c₂ + T(c₃ + T c₄)))

    Material packs: property curves by temperature engineer/material-pack.js
    • PartCraft
    64-bit
  • Property at a temperature

    The property value with its unit, range, fit error and source.

    value = curve(T) × scale

    Material packs: property curves by temperature engineer/material-pack.js
    • PartCraft
    64-bit
  • Series coefficients

    The factors 1/n! of the sine and cosine series.

    cₙ = ±1 ÷ n!

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Angle reduction

    Brings an angle into [−π, π].

    n = floor(x ÷ 2π + ½); r = (x − n × 2π_hi) − n × 2π_lo

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Sine series

    The sine of a reduced angle.

    sin r = r(c₀ + c₁r² + … + c₁₂r²⁴)

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Cosine series

    The cosine of a reduced angle.

    cos r = c₀ + c₁r² + … + c₁₂r²⁴

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Sine

    sin x for any finite x.

    sin r = sin(π − r) for r > π/2; sin r = sin(−π − r) for r < −π/2

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Cosine

    cos x for any finite x.

    cos r = −cos(π − |r|) for |r| > π/2

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Exponential

    The exponential eˣ of a number.

    k = floor(x ÷ ln 2 + ½); r = (x − k × ln2_hi) − k × ln2_lo; eˣ = 2ᵏ × Σ rⁿ ÷ n! (n = 0 … 18)

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Natural logarithm

    The natural logarithm ln x of a number.

    x = m × 2ᵉ, m in [√2/2, √2]; ln m = 2(s + s³/3 + … + s²⁹/29), s = (m − 1) ÷ (m + 1); ln x = e × ln2_hi + (ln m + e × ln2_lo)

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Base-2 logarithm

    The base-2 logarithm log₂ x of a number.

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Base-10 logarithm

    The base-10 logarithm log₁₀ x of a number.

    log₁₀ x = ln x ÷ 2.302585092994046

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Whole-number power

    xⁿ for a whole n ≥ 0.

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Power

    A number x raised to a power y.

    xʸ = exp(y × ln x) for a fractional y

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Arctangent

    The arctangent atan x of a number.

    atan z = 2·atan(z ÷ (1 + √(1 + z²))), twice; then 4(z − z³/3 + … + z⁴¹/41)

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Two-argument arctangent

    The angle of the point (x, y).

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Arcsine

    The arcsine asin x of a number in [−1, 1].

    asin x = atan2(x, √((1 − x)(1 + x)))

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Arccosine

    The arccosine acos x of a number in [−1, 1].

    acos x = 2·atan2(√(1 − x), √(1 + x))

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Tangent

    The tangent tan x of an angle.

    tan x = sin x ÷ cos x

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Hyperbolic sine

    The hyperbolic sine sinh x of a number.

    sinh x = (eˣ − e⁻ˣ) ÷ 2

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Hyperbolic cosine

    The hyperbolic cosine cosh x of a number.

    cosh x = (eˣ + 1 ÷ eˣ) ÷ 2

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Hyperbolic tangent

    The hyperbolic tangent tanh x of a number.

    tanh x = (e²ˣ − 1) ÷ (e²ˣ + 1)

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Cube root

    The cube root ∛x of a number.

    r₀ = exp(ln|x| ÷ 3); r ← r − (r³ − |x|) ÷ (3r²), twice

    Deterministic sine, cosine, exp, log and power field/detmath.js
    • PartCraft
    64-bit
  • Sphere

    Signed distance to a sphere.

    d = √((x − cx)² + (y − cy)² + (z − cz)²) − r

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Box with rounded edges

    Signed distance to a box, optionally with rounded edges and corners.

    q = |p − c| − (half − round); d = |max(q, 0)| + min(max(q_x, q_y, q_z), 0) − round

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Cylinder

    Signed distance to a cylinder between two points.

    t = (p − m)·u; d_r = |p − m − t·u| − r; d_t = |t| − L ÷ 2; d = |max(d_r, d_t, 0)| + min(max(d_r, d_t), 0)

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Torus

    Signed distance to a torus about the z axis.

    d = √((√(x² + y²) − R)² + z²) − r

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Half space

    Signed distance to a plane.

    d = (n·p − d₀) ÷ |n|

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Solid of revolution

    Signed distance to the solid under a profile r(x) turned about the x axis.

    ρ = √(y² + z²); d = least distance from (x, ρ) to the profile's segments; inside when ρ ≤ r(x)

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit
  • Union, intersection and subtraction

    Combines shapes by union, intersection or subtraction.

    union = min(a, b); intersection = max(a, b); subtraction = max(a, −b)

    Field shapes: signed distance functions field/field.js
    • PartCraft
    64-bit

A calculation is added only after its source was read. Each statement can be checked in the code shown on its policy's page; the app repositories are public. When a release changes a calculation, its page says so until it has been read again.