Length

Length units and conversions. More...

Collaboration diagram for Length:

Files
file	units_length.scad
	Length units and conversions.

Functions
function	unit_length_name (units=base_unit_length, d=1, w=false)
	Return the name of the given unit identifier with dimension. More...
function	convert_length (value, from=base_unit_length, to=base_unit_length, d=1)
	Convert the value from from units to to units with dimensions. More...

Variables
	base_unit_length = "mm"
	<string> Base unit for length measurements.

Detailed Description

Length units and conversions.

These functions allow for lengths to be specified with units. Lengths specified with units are independent of (base_unit_length). There are also unit conversion functions for converting from one unit to another.

The table below enumerates the supported unit identifiers and their descriptions.

units id	description
pm	picometer
nm	nanometer
um	micrometer
mm	millimeter
cm	centimeter
dm	decimeter
m	meter
km	kilometer
thou, mil	thousandth of an inch
in	inch
ft	feet
yd	yard
mi	mile

Example

    include <units_length.scad>;

    base_unit_length = "mm";

    // get base unit name
    un = unit_length_name();

    // absolute length measurements in base unit.
    c1 = convert_length(1/8, "in");
    c2 = convert_length(3.175, "mm");
    c3 = convert_length(25, "mil");
    c4 = convert_length(1, "ft", d=3);

    // convert between units.
    c5 = convert_length(10, from="mil", to="in");
    c6 = convert_length(10, from="ft", to="mm");

Result (base_unit_length = mm):

ECHO: un = "millimeter"
ECHO: c1 = 3.175
ECHO: c2 = 3.175
ECHO: c3 = 0.635
ECHO: c4 = 2.83168e+07
ECHO: c5 = 0.01
ECHO: c6 = 3048

Result (base_unit_length = cm):

ECHO: un = "centimeter"
ECHO: c1 = 0.3175
ECHO: c2 = 0.3175
ECHO: c3 = 0.0635
ECHO: c4 = 28316.8
ECHO: c5 = 0.01
ECHO: c6 = 3048

Result (base_unit_length = mil):

ECHO: un = "thousandth"
ECHO: c1 = 125
ECHO: c2 = 125
ECHO: c3 = 25
ECHO: c4 = 1.728e+12
ECHO: c5 = 0.01
ECHO: c6 = 3048

Result (base_unit_length = in):

ECHO: un = "inch"
ECHO: c1 = 0.125
ECHO: c2 = 0.125
ECHO: c3 = 0.025
ECHO: c4 = 1728
ECHO: c5 = 0.01
ECHO: c6 = 3048

Example (equivalent lengths)

Unit Lengths

Function Documentation

function convert_length	(	value	,
		from	= base_unit_length,
		to	= base_unit_length,
		d	= 1
	)

Convert the value from from units to to units with dimensions.

Parameters

value	<decimal> A value to convert.
from	<string> The units of the value to be converted.
to	<string> A units to which the value should be converted.
d	<decimal> The dimension set to one of [1|2|3].

Returns

<decimal> The conversion result. Returns 'undef' for identifiers or dimensions that are not defined.

function unit_length_name	(	units	= base_unit_length,
		d	= 1,
		w	= false
	)

Return the name of the given unit identifier with dimension.

Parameters

w	<boolean> true: use word format, false: use symbol format.
units	<string> A length unit identifier.
d	<decimal> A dimension set to one of [1|2|3].

Returns

<string> The units name for the given length unit identifier with is specified dimension. Returns 'undef' for identifiers or dimensions that are not defined.