Magnitude of value with units

Comments

• paul_chastell Onshape Employees Posts: 126

  July 2017 edited July 2017

  I would suggest you divide by the unit you are interested in, and ignore the internal representation. If you have a length and what to know how many meters it is then you can do "var lengthInMeters = length / meter". It doesn't matter what unit 'length' has. Or "length / inch" to get the length in inches. In both cases the result is a unitless value.
  
  E.g. this custom feature measures the distance between two points, in inches, and logs it to the console
  
  

  <div>annotation { "Feature Type Name" : "Distance in Inches" }
  </div><div>export const inchDistance = defineFeature(function(context is Context, id is Id, definition is map)
  </div><div>&nbsp; &nbsp; precondition
  </div><div>&nbsp; &nbsp; {
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; annotation { "Name" : "Points", "Filter" : EntityType.VERTEX, "MaxNumberOfPicks" : 2 }
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; definition.points is Query; &nbsp; &nbsp; &nbsp; &nbsp;
  </div><div>&nbsp; &nbsp; }
  </div><div>&nbsp; &nbsp; {
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; if (size(evaluateQuery(context, definition.points)) == 2)
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; {
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp;     var result = evDistance(context, {
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "side0" : qNthElement(definition.points, 0),
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "side1" : qNthElement(definition.points, 1)
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp;     });
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp;     println("Distance in inches is: " ~ (<b>result.distance / inch</b>));
  </div><div>&nbsp; &nbsp; &nbsp; &nbsp; }
  </div><div>&nbsp; &nbsp; });
  
  </div>

  Paul Chastell
  TVP, Onshape R&D

  2
• ilya_baran Onshape Employees, Developers, HDM Posts: 1,245

  July 2017

  Paul is absolutely right.  But if you're curious about what the representation is, you can look at units.fs in std or do println("" ~ inch);

  Ilya Baran \ VP, Architecture and FeatureScript \ Onshape Inc

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• konstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭

  July 2017

  ok, thank you Ilya and Paul, I found out that ValueWithUnits is internally a map and "value" field contains magnitude
  

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