Function Repository Resource:

# PhysicalQuantityLookup

Look up PhysicalQuantity entities using units or unit dimensions

Contributed by: Jason Martinez
 ResourceFunction["PhysicalQuantityLookup"][arg] returns the list of physical quantities which share the unit dimensionality of arg. ResourceFunction["PhysicalQuantityLookup"][arg,type] returns physical quantities in the format specified by type.

## Details

arg can be a Quantity, a "PhysicalConstant" Entity, unit dimension list or a QuantityVariable defined by a unit dimension list.
By default ResourceFunction["PhysicalQuantityLookup"] returns a list of a "PhysicalConstant" entities.
type defines the format of the output and can be one of the following:
 “Entity" "PhysicalQuantity" entities “QuantityVariable" QuantityVariable object “QuantityVariableName" string names

## Examples

### Basic Examples (3)

Find all physical quantities with the same dimensions as ohms:

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Look for physical quantities that cover a quantity:

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Search by specifying unit dimensions:

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### Scope (2)

Find the physical quantity corresponding to the gravitational constant:

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Obtain the quantity variables for the physical quantities where available:

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Get the names for a given quantity unit:

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Construct custom variables for these names:

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### Applications (3)

Obtain the dimensions of energy:

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Examine all physical quantities with these dimensions:

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Graph and group the physical quantities according to their base physical quantity:

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### Properties and Relations (2)

Canonical units for physical quantities may differ from the unit used to find them:

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Unit dimensions can be determined with UnitDimensions or QuantityVariableDimensions:

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### Possible Issues (2)

Combinations of units can be queried by specifying them in a Quantity:

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Some combinations of units or unit dimensions do not have an associated physical quantity:

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Use the unit dimensions within a QuantityVariable to work with these sort of situations:

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## Version History

• 1.0.0 – 28 March 2022

## Author Notes

PhysicalQuantityLookup uses entity class lookups and so relies on an internet connection.