Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.

First time visiting? Here are some places to start:
  1. Looking for a certain topic? Check out the categories filter or use Search (upper right).
  2. Need support? Ask a question to our Community Support category.
  3. Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
  4. Be respectful, on topic and if you see a problem, Flag it.

If you would like to contact our Community Manager personally, feel free to send a private message or an email.

"normalize" documentation

brooke_spreen
brooke_spreen Member, Developers Posts: 115 ✭✭✭
edited February 2021 in FeatureScript
It looks like the documentation for the function "normalize" has been updated recently. I find it rather difficult to interpret.....if I had not used it several times in the past, it would be difficult to figure out which function would give me the Direction of a vector. This could maybe use some clarification? Perhaps "returns Direction" instead of "returns Vector" in the first line of documentation?

normalize (vector is Vector) returns Vector

Returns the (unitless) result of normalizing vector. Throws if the input is zero-length.

Design Engineer | Anerdgy AG
Tagged:

Comments

  • konstantin_shiriazdanov
    konstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    Direction is not a type in onshape, it's just a name of a field of some data types which is supposed to contain unitless vector of length 1, mathematically it's just v0 = v/|v|. For someone would be more confusing to have directions and vectors not being the same type.
  • brooke_spreen
    brooke_spreen Member, Developers Posts: 115 ✭✭✭
    That's not entirely true. If you run `debug(context, a_dir)`, the readout recognizes that it is a direction. Regardless, I think it would be informative to mention something about "direction" in the description!
    Design Engineer | Anerdgy AG
  • caden_armstrong2
    caden_armstrong2 Member, User Group Leader Posts: 121 ✭✭✭
    Something you have to remember is that a vector with units can still be describing a direction. With units, that vector also has a magnitude. An example of this is in the StartDerivative field in the opFitSpline operation.

    The normalize function does not give you the "direction" of a vector, a vector is a direction. The resulting vector is in the same direction, but the magnitude is 1 (unitless).
    Normalizing is a common mathematical term, just as dot product and cross products are.

    Types such as "line" specify direction to differentiate between the two vectors in the definition, one for a point and one for a direction. Both are vectors that could be normalized. Vector is the data type, direction is the purpose.

  • brooke_spreen
    brooke_spreen Member, Developers Posts: 115 ✭✭✭
    The normalize function returns the unit vector of the given vector. This is what OS seems to refer to as a "Direction".  A bit of documentation from the `vector` module:

    is3dDirection (value) predicate

    True for a unitless 3D Vector that is normalized (i.e. has length 1)

    EXAMPLE

    vector(0, 0, 1)

    Though perhaps to avoid confusion the terminology "unit vector" is a safer bet :)
    Design Engineer | Anerdgy AG
  • konstantin_shiriazdanov
    konstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    brooke_spreen said:

    Though perhaps to avoid confusion the terminology "unit vector" is a safer bet :)
    a unitless unit vector!

  • brooke_spreen
    brooke_spreen Member, Developers Posts: 115 ✭✭✭
    Hehe yes ;D
    Design Engineer | Anerdgy AG

Categories