Question 1

How do I convert Celsius to Fahrenheit accurately in Ruby Units?

Accepted Answer

Use Unit.new('37 tempC').convert_to('tempF') to get 98.6 tempF. Remember to use 'temp' prefixes for absolute temperatures to account for scale zero points, unlike 'deg' for differences.

Question 2

Can Ruby Units handle time durations like adding minutes to a Time object?

Accepted Answer

Yes, it extends Ruby's Time class: Time.now + Unit.new('10 min') works naturally. For large units like years, it converts to days for calendar accuracy, so use hours or seconds for exact durations.

Question 3

What's the difference between Ruby Units and other gems like 'units'?

Accepted Answer

Ruby Units offers deeper integration with Ruby's core classes and Math functions, plus accurate temperature handling, but it may be heavier. For basic conversions, simpler gems might suffice, but for scientific rigor, Ruby Units is stronger.

Question 4

How to define a custom unit, say for energy, in Ruby Units?

Accepted Answer

Use Unit.define with a block: specify definition (e.g., Unit.new('1 J')), aliases, and display_name. For complex units, set scalar, kind, and numerator/denominator arrays, as shown in the electron-volt example.

Question 5

Does Ruby Units work with Rails applications?

Accepted Answer

Yes, add gem 'ruby-units' to your Gemfile. However, ensure your Ruby version is 3.2+, and test performance in high-traffic scenarios due to its accuracy-focused design.

Question 6

Why does Ruby Units raise errors when adding two temperatures?

Accepted Answer

Because adding absolute temperatures is physically meaningless; it only allows adding temperature differences to temperatures. The library enforces this to maintain accuracy, as explained in the Temperature Handling section.

Question 7

How to format unit output with specific precision in Ruby Units?

Accepted Answer

Use to_s with format strings: Unit.new('1.5 mm').to_s('%0.2f') gives '1.50 mm'. Configure globally via RubyUnits.configure for separators and rational/exponential formatting.

Ruby Units

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