Uniq! not working ?

remus

im using this:
` model = Sketchup.active_model
entities = model.entities
selection = model.selection

faces = []

face = selection[0]

face.edges.each{|e| faces.push(e.faces)}

faces.uniq!

puts faces`

to try and create an array of the faces connected to a face, but for whatever reason im getting lots of duplicates of the selected face. I tried writing my own mini version of uniq and that didnt do the trick either, so im at a bit of a loss.

thomthom

You are inserting arrays of faces, so you have an array of arrays of faces. try to flatten the array first.

faces.flatten!.uniq!

Sidenote: you might find the Set class faster to keep a collection of unique objects. Array isn't very efficient for large collections - especially the .include? method....

remus

yay, thanks. I thought it was going to be something obvious but had a complete mental blank.

with regards to using sets, its only a small array (max 20-30 elements) so it shouldnt matter.

thomthom

@remus said:

with regards to using sets, its only a small array (max 20-30 elements) so it shouldnt matter.

Then Arrays might be faster.

Jim

You can also use Array.concat to append new arrays as elements instead of a single array.


a = []
a.push([1, 2, 3])
==> [[1, 2, 3]]

a = []
a.concat([1, 2, 3])
==> [1, 2, 3]

fredo6

@remus said:

face.edges.each{|e| faces.push(e.faces)}

The correct code should be something like:
face.edges.each { |e| faces += e.faces }

For small numbers of elements, uniq! should be OK. Otherwise, you might consider using a Hash or a Set to avoid redundant elements.

Fredo

remus

Fredo, it gives me a syntax error when i try that, bear in mind faces is an array (and i dont think += is defined for arrays.)

mitcorb

Excuse me for stepping in here.
Out of curiosity, are there a lot of terms like "uniq" in the ruby language? Couldn't this get confusing? Or can you use interchangeably "unique"?

remus

I dont think you can use "unique" interchangeably but its not too confusing really, if anything i find the differences help you remember the methods.

mitcorb

Thanks, Remus.
Again, please excuse the intrusion.

TIG

SUp's own .make_unique method only applies to groups and instances of component definitions.
Its .unique_name methods applies to definitions and layers name creation.
Ruby's own .uniq method returns an array (etc) of unique items ('cloned'), missing out duplicates,,,
array1=[1,1,2,3]; array2=array1.uniq >>> array2 returns [1,2,3] but array1 still returns [1,1,2,3]
whereas using .uniq! changes the original array to a unique one...
array1=[1,1,2,3]; array1.uniq! >>> array1 now returns [1,2,3]

All very useful in there own ways...

Dan Rathbun

@remus said:

...to try and create an array of the faces connected to a face...

EdgeUse.partners
http://code.google.com/apis/sketchup/docs/ourdoc/edgeuse.html#partners
@unknownuser said:

The partners method is used to retrieve all of the partner edge uses. This method allows you to find all Faces that use an edge.

EDIT: Never-mind. I think the flatten! array means by ThomThom is much simpler. Compact code, let ruby do the hard work.

Dan Rathbun

@mitcorb said:

Excuse me for stepping in here.
Out of curiosity, are there a lot of terms like "uniq" in the ruby language? Couldn't this get confusing?

Many of the method names came from Unix and Perl, so they are familiar to people with that background. Well there are some 'shortened nicknames', such as: assoc, eql, attr, dup, eval, stat, sync, const, undef,... etc. sprinkled throughout ruby modules, but No not a majority. A very small minority in fact. But you get used to them.

@mitcorb said:

Or can you use interchangeably "unique"?

You could (if you felt more comfortable,) create singleton methods that provide an alias.


arr = [1,2,1,3,4]

def arr.unique!
  self.uniq!
end

arr.unique!
 >> [1,2,3,4]

arr2=[5,6,7,5]
arr2.unique!
 >> Error; #<NoMethodError; undefined method `unique!' for [5, 6, 7, 5];Array>

So it only works for the single instance 'arr'.
This avoids globally changing Base classes, which most people get upset about.

fredo6

@remus said:

Fredo, it gives me a syntax error when i try that, bear in mind faces is an array (and I dont think += is defined for arrays.)

It must be something else (do you have a precise description of the error).
+ is defined for Arrays (it's equivalent to concat), so += is meaningful (I use it frequently).

Fredo

thomthom

@unknownuser said:

@remus said:

Fredo, it gives me a syntax error when i try that, bear in mind faces is an array (and I dont think += is defined for arrays.)

It must be something else (do you have a precise description of the error).
+ is defined for Arrays (it's equivalent to concat), so += is meaningful (I use it frequently).

Fredo

I get a syntax error as well:


[1,2,3] += [4,5]
Error; #<SyntaxError; (eval);894; compile error
(eval);894; syntax error
[1,2,3] += [4,5]
          ^>
(eval);894

Is it not that you have some code that has added this as extra functionality?

thomthom

hm... when I defined the variables face and faces - and ran the code - it worked....
face.edges.each { |e| faces += e.faces }

now I'm confused

fredo6

Tom,

It only works on variables, because you actually modify the contnet of the left-side array (and I guess [3,5] is considered as a constant).

I tried in the console:


a = [1,2]
[1, 2]
b = [3, 4]
[3, 4]
a += b
[1, 2, 3, 4]

[1,2] += b
Error; #<SyntaxError; (eval);130; compile error
(eval);130; syntax error
[1,2] += b
        ^>
(eval);130

Fred

remus

Working now Must have missed something last time i tried it.