New pl-units-input Element

Thanks to Eliot Robson (UIUC), PrairieLearn now has a new pl-units-input element, based on preliminary work by Morgan Arnold and Boris Li (UBC).

This element can be used to create problems where students must input a quantity with an accompanying unit. By default, input of the same dimensionality as the reference solution is automatically converted and compared. For example, if the correct answer is 1 meter, submissions like 100 cm or 1000 mm are also accepted.

Below are submission panels for correct answers. For the second one, the comparison was performed independent of units and within the given tolerance (1cm).

In the following example, the student used an incompatible unit (cm^3 instead of m), resulting in an answer tagged as incorrect.

Additional comparison methods are available without this automated conversion, along with other customization options. The code that generates the above question is:

<pl-units-input answers-name="c_1" correct-answer="1m" atol="1cm"></pl-units-input>

For more information, see the pl-units-input documentation or the pl-units-input example question.