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

  • Cut-out inside its area

    Checks that a cut-out lies fully inside the outline and does not overlap another cut-out.

    Outline checks: inside, crossing, cut-outs geom.js
    • TakeoffCraft
    64-bit
  • Convex outline test

    Whether a closed outline has no inward corner.

    Back-outs clipped out of areas geom.js
    • TakeoffCraft
    64-bit
  • Polygon clipped to a convex polygon

    The part of a polygon that lies inside a convex polygon.

    t = d₁ ÷ (d₁ − d₂); corner = p + (q − p)·t

    Back-outs clipped out of areas geom.js
    • TakeoffCraft
    64-bit
  • Area a back-out covers

    How much of an area mark (outline minus cut-outs) a convex back-out covers, in square PDF units.

    overlap = max(0, A(outline ∩ b) − Σ A(cut-out ∩ b))

    Back-outs clipped out of areas geom.js
    • TakeoffCraft
    64-bit
  • Net area shown for a mark

    The area in a mark's properties after its back-outs are taken off.

    net = max(0, area − cut); plan area = max(0, plan − cut ÷ factor)

    Back-outs clipped out of areas takeoffcraft.js
    • TakeoffCraft
    64-bit
  • Typed length to feet

    Normalizes what was typed and reads it as one length, or as arithmetic over lengths.

    Typed lengths and item units units.js
    • TakeoffCraft
    64-bit
  • One length with a metric unit, or feet and inches

    Reads one normalized length into feet.

    ft = meters ÷ 0.3048

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Numbers and fractions in a typed length

    Splits the text into numbers, fractions and foot or inch marks.

    fraction = a ÷ b (integers)

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Feet and inches combined

    Combines a feet part and an inches part (whole number plus fraction) into feet.

    ft = feet + (inches + fraction) ÷ 12

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Bare number in the default unit to feet

    Converts a number in feet, inches, meters, centimeters or millimeters to feet.

    ft = v ÷ 12; ft = v ÷ 0.3048; ft = v ÷ 1000 ÷ 0.3048

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Item unit factors

    The factor from feet or square feet to each unit an item can be reported in.

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Feet and square feet into an item's unit

    Converts a length in feet or an area in square feet to the unit that goes with an item.

    m = ft × 0.3048; area = sf × perSqFt

    Typed lengths and item units units.js
    • TakeoffCraft
    Exact
  • Round half away from zero

    Rounds a number to a given count of decimals.

    r = ⌊|v|·10ᵈ + 0.5 + 1e-9·max(1, |v|·10ᵈ)⌋ ÷ 10ᵈ

    Rounding for display and for money units.js
    • TakeoffCraft
    64-bit
  • Grouped fixed-point text

    Writes a number with a fixed count of decimals and thousands separators.

    Rounding for display and for money units.js
    • TakeoffCraft
    64-bit
  • Feet and inches to the nearest fraction

    Writes a length in feet as feet, inches and a fraction of an inch.

    n = round(|ft|·12·denom + 1e-9); feet = ⌊n ÷ (12·denom)⌋; inches = ⌊rem ÷ denom⌋

    Rounding for display and for money units.js
    • TakeoffCraft
    64-bit
  • Length in a chosen display unit

    Writes a length in feet-inches, decimal feet, inches, meters or millimeters.

    m = ft × 0.3048; mm = ft × 0.3048 × 1000

    Rounding for display and for money units.js
    • TakeoffCraft
    64-bit
  • Feet per sheet unit for a named scale

    The scale number for a preset such as 1/4 inch = 1 foot or 1:100.

    ftPerUnit = (userUnit ÷ 72) × ratio ÷ 12

    Sheet scale: presets, calibration and drawing units units.js
    • TakeoffCraft
    Exact
  • Scale from two points and a typed distance

    The scale that makes the distance between two picked points equal a typed real distance.

    ftPerUnit = realFt ÷ |b − a|

    Sheet scale: presets, calibration and drawing units units.js
    • TakeoffCraft
    64-bit
  • Named scale a number matches

    Finds the preset scale closest to a scale number, if any is close enough.

    err = |ftPerUnit − s| ÷ s ≤ 0.005

    Sheet scale: presets, calibration and drawing units units.js
    • TakeoffCraft
    64-bit
  • Feet per drawing unit by INSUNITS code

    The table that turns a drawing's unit code into feet per drawing unit.

    code 6: 1 ÷ 0.3048; code 21 as written: 1200 ÷ 3937

    Sheet scale: presets, calibration and drawing units cadcount.js
    • TakeoffCraft
    64-bit
  • The drawing's length unit

    Reads the INSUNITS code and looks up feet per drawing unit.

    Sheet scale: presets, calibration and drawing units cadcount.js
    • TakeoffCraft
    64-bit
  • Viewport transform, model to paper

    The matrix that places model space on the paper through a layout's viewport.

    k = h ÷ viewHeight; M = [k·c, k·s, −k·s, k·c, cx − k(c·vx − s·vy), cy − k(s·vx + c·vy)]

    Sheet scale: presets, calibration and drawing units cadset.js
    • TakeoffCraft
    64-bit
  • Sheet size and the drawing-to-page transform

    Puts a layout on a page in points, or fits model space to a page about 2000 units on its longest side.

    layout: page = (paper − min) × ptU; model: k = 2000 ÷ extent, page = k·x + (24 − k·minX)

    Sheet scale: presets, calibration and drawing units cadset.js
    • TakeoffCraft
    64-bit
  • Scale a drawing's sheet starts with

    Feet per page unit for a model sheet or a layout.

    model: f = ft ÷ k; layout: f = (1 ÷ ptU) ÷ s × ft, s = h ÷ viewHeight

    Sheet scale: presets, calibration and drawing units cadset.js
    • TakeoffCraft
    64-bit
  • Drawing scale taken over by the takeoff

    Gives each sheet of an opened drawing the scale the drawing itself states, when the sheet has none yet.

    Sheet scale: presets, calibration and drawing units takeoffcraft.js
    • TakeoffCraft
    64-bit
  • Calibration stored on the sheet

    Reads the typed distance, computes the scale and stores it with the two points and the text.

    Sheet scale: presets, calibration and drawing units takeoffcraft.js
    • TakeoffCraft
    64-bit
  • Typed unit rate

    Reads a rate such as $1,234.5 into whole 1 ÷ 10000 dollars.

    rate4 = round(roundTo(v, 4) × 10000)

    Rates, percentages and extended amounts units.js
    • TakeoffCraft
    Exact
  • Typed percentage

    Reads a percentage such as 7.5 % into whole basis points.

    bp = round(roundTo(v, 2) × 100)

    Rates, percentages and extended amounts units.js
    • TakeoffCraft
    Exact
  • Quantity × rate to the cent

    The extended amount of a line in whole cents.

    cents = round(qty × rate4 ÷ 100)

    Rates, percentages and extended amounts units.js
    • TakeoffCraft
    64-bit
  • Quantity with waste

    A quantity increased by a waste percentage.

    qtyW = qty × (1 + bp ÷ 10000)

    Rates, percentages and extended amounts units.js
    • TakeoffCraft
    64-bit
  • Cents as dollars text

    Writes whole cents as $1,234.56.

    Rates, percentages and extended amounts units.js
    • TakeoffCraft
    Exact
  • Typed bid amount to cents

    Reads an amount typed into the bid leveling sheet as whole cents.

    cents = round(rate4 ÷ 100)

    Rates, percentages and extended amounts takeoffcraft.js
    • TakeoffCraft
    Exact
  • Typed pitch to rise per 12

    Reads 6:12, 6/12, 4:10, a bare rise, or an angle in degrees.

    rise = tan(a·π ÷ 180) × 12; rise = rise ÷ run × 12

    Roof pitch and slope factors units.js
    • TakeoffCraft
    64-bit
  • Slope factor of a roof plane

    Surface length or area per unit of plan length or area.

    f = √(1 + (rise ÷ 12)²)

    Roof pitch and slope factors units.js
    • TakeoffCraft
    64-bit
  • Hip and valley factor

    True length of a hip or valley per unit of its plan length.

    f = √(1 + (rise ÷ 12)² ÷ 2)

    Roof pitch and slope factors units.js
    • TakeoffCraft
    64-bit
  • Pitch as text

    Writes the rise as 6:12 or 6.5:12.

    Roof pitch and slope factors units.js
    • TakeoffCraft
    64-bit
  • Signed coordinate length

    Reads one typed coordinate, which may be negative or zero, into feet.

    Typed distances and coordinates while drawing typein.js
    • TakeoffCraft
    64-bit
  • Sheet direction of a screen direction

    The unit vector on the sheet that points along a given direction on the screen.

    u = M⁻¹·(sx, −sy); u ÷ |u|

    Typed distances and coordinates while drawing typein.js
    • TakeoffCraft
    64-bit
  • Point from typed text

    Works out the next point from a distance, a distance and angle, or coordinates.

    p = last + dir × ft × k, k = 1 ÷ ftPerUnit

    Typed distances and coordinates while drawing typein.js
    • TakeoffCraft
    64-bit
  • Circle radius typed while drawing

    Places a circle's edge point at a typed radius from its center, toward the pointer.

    edge = c + (to − c) ÷ |to − c| × ft ÷ ftPerUnit

    Typed distances and coordinates while drawing takeoffcraft.js
    • TakeoffCraft
    64-bit
  • Typed spot elevation

    Reads the elevation typed on a count mark, in decimal feet, feet-inches or meters.

    Typed distances and coordinates while drawing takeoffcraft.js
    • TakeoffCraft
    64-bit
  • One CAD object as points and bulges

    The run or outline that stands for a line, arc, circle, polyline, ellipse, spline or 2D solid.

    arc: p = c + r·(cos a, sin a), b = tan(sweep ÷ 4); ellipse: n = max(24, ⌈1440·sweep ÷ 2π⌉) chords

    Lengths and areas taken from CAD objects cadgeom.js
    • TakeoffCraft
    64-bit
  • Hatch as outlines with holes

    The outer loops of a hatch, each with the loops inside it as cut-outs.

    Lengths and areas taken from CAD objects cadgeom.js
    • TakeoffCraft
    64-bit
  • Object placed on the sheet

    Applies the sheet or viewport matrix to an object's points and decides whether a viewport shows it.

    p′ = T·(mirror·x, y); b′ = b × sign(det T × mirror)

    Lengths and areas taken from CAD objects cadgeom.js
    • TakeoffCraft
    64-bit
  • Marks made from picked objects

    The point lists a linear or an area item takes from the picked objects.

    Lengths and areas taken from CAD objects cadgeom.js
    • TakeoffCraft
    64-bit
  • Length and area of what is picked

    The total length or net area of the picked objects in page units.

    len = Σ length; area = Σ (gross − cut-outs)

    Lengths and areas taken from CAD objects cadgeom.js
    • TakeoffCraft
    64-bit
  • Picked objects in real units

    The length or area of the picked CAD objects shown above the sheet.

    SF = area × k²; ft = len × k

    Lengths and areas taken from CAD objects takeoffcraft.js
    • TakeoffCraft
    64-bit
  • Product of two transforms

    Combines two 2 × 3 affine matrices.

    Counting blocks, shapes and texts in a CAD drawing cadcount.js
    • TakeoffCraft
    64-bit
  • Place of a block reference and its array cells

    The point of each copy of a block reference, and the transform its contents get.

    p = M·(insert + R(rot)·(c·dx, r·dy))

    Counting blocks, shapes and texts in a CAD drawing cadcount.js
    • TakeoffCraft
    64-bit
  • Point that stands for a shape

    The one point a shape is placed and counted by: a center, a middle, or the middle of its box.

    Counting blocks, shapes and texts in a CAD drawing cadcount.js
    • TakeoffCraft
    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.