Variable problem

chrisglasier

Please would someone be kind enough to show me how to sort out this snippet?


def kf(time)
keyframes = {}
model = Sketchup.active_model
d = model.attribute_dictionaries['kframes']
d.each_pair do | key,value |
a =  1
value.each do | v |
if v.nil?
v = [[1,0,0],0]
end
v << time * a
a += 1
end
keyframes[key] = value
end
return keyframes
end

When I puts the v's all are correct, but value returns the previously nil v' s to nil. Just cannot see why!

Thanks

thomthom

It doesn't work as you expect because you are not changing the content of the array. You're dealing with a local copy.
I changed your loop to use .map - that should work. (untested)

<span class="syntaxdefault"><br />def kf</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">time</span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">  keyframes </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">{}<br /></span><span class="syntaxdefault">  model </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> Sketchup</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_model<br />  d </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">attribute_dictionaries</span><span class="syntaxkeyword">[</span><span class="syntaxstring">'kframes'</span><span class="syntaxkeyword">]<br /></span><span class="syntaxdefault">  d</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">each_pair do </span><span class="syntaxkeyword">|</span><span class="syntaxdefault"> key</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">value </span><span class="syntaxkeyword">|<br /></span><span class="syntaxdefault">    a </span><span class="syntaxkeyword">=</span><span class="syntaxdefault">  1<br />    value</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">map do </span><span class="syntaxkeyword">|</span><span class="syntaxdefault"> v </span><span class="syntaxkeyword">|<br /></span><span class="syntaxdefault">      if v</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">nil</span><span class="syntaxkeyword">?<br /></span><span class="syntaxdefault">        v </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">[[</span><span class="syntaxdefault">1</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">],</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">]<br /></span><span class="syntaxdefault">      end<br />      v </span><span class="syntaxkeyword"><<</span><span class="syntaxdefault"> time </span><span class="syntaxkeyword">*</span><span class="syntaxdefault"> a<br />      a </span><span class="syntaxkeyword">+=</span><span class="syntaxdefault"> 1<br />      v<br />    end<br />    keyframes</span><span class="syntaxkeyword">[</span><span class="syntaxdefault">key</span><span class="syntaxkeyword">]</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> value<br />  end<br />  return keyframes<br />end<br /></span>

chrisglasier

@thomthom said:

It doesn't work as you expect because you are not changing the content of the array. ....

Thanks but I am sorry to say it doesn't work at all.

Also my original code successfully adds the time to each ( v) array, it only seems the nil block is being ignored by value.

So I don't know ...

chrisglasier

.... but map does work if there aren't any nil elements in the value arrays.

thomthom

@chrisglasier said:

Thanks but I am sorry to say it doesn't work at all.

sorry, should be .map!

@chrisglasier said:

Also my original code successfully adds the time to each (v) array, it only seems the nil block is being ignored by value.

Yes, because nil is immutable.

TIG

value.each do | v |
if v.nil?
  v = [[1,0,0],0]
end
v << time * a
a += 1
end
keyframes[key] = value
end

looks through the contents of 'value' and assigns some values to elements in array 'v', then it sets the keyframes[key] back to be value ???
Don't you want to modify 'key'?
Why don't you use keyframes[key] = v ???

chrisglasier

@tig said:

value.each do | v |
> if v.nil?
>   v = [[1,0,0],0]
> end
> v << time * a
> a += 1
> end
> keyframes[key] = value
> end

looks through the contents of 'value' and assigns some values to elements in array 'v', then it sets the keyframes[key] back to be value ???

Don't you want to modify 'key'?
Why don't you use keyframes[key] = v ???

Value is an array of arrays (like [[1,0,0],0]). So v is one of those. I am sure it is caused by the nil block? (immutable??). Perhaps I should make a new array from the v's because they are OK.

I will try that later or tomorrow.

Thanks for your help.

TIG

In which case

  ...
  new_value = []
  value.each do | v |
    if v ### ??? ### isn't this what you want ?***
      v << time * a
    else ### OR it's nil
      v = [[1,0,0],0]
    end ### ***if NOT then revert to your format...
    new_value << v
    a += 1
  end
    keyframes[key] = new_value
  end

chrisglasier

@tig said:

In which case

  ...
>   new_value = []
>   value.each do | v |
>     if v ### ??? ### isn't this what you want ?***
>       v << time * a
>     else ### OR it's nil
>       v = [[1,0,0],0]
>     end ### ***if NOT then revert to your format...
>     new_value << v
>     a += 1
>   end
>     keyframes[key] = new_value
>   end
>

Yes that looks good;I guess I can use v.is_a?(Array) for the if bit as the nil candidates are just empty elements.

Thanks to you both ...

TIG

if v returns true if v is not nil or not []
The else then takes it's 'converse' i.e. it is nil OR []
I'm not clear about how a good or bad entry for 'value >>> v' might actually 'look' in your code...

chrisglasier

@tig said:

I'm not clear about how a good or bad entry for 'value >>> v' might actually 'look' in your code...

<span class="syntaxdefault">new_value </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">[]<br /></span><span class="syntaxdefault">            value</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">each do</span><span class="syntaxkeyword">|</span><span class="syntaxdefault"> v </span><span class="syntaxkeyword">|<br /></span><span class="syntaxdefault">                if </span><span class="syntaxkeyword">!</span><span class="syntaxdefault">v</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(Array)<br /></span><span class="syntaxdefault">                    v </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">[[</span><span class="syntaxdefault">1</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">,</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">],</span><span class="syntaxdefault">0</span><span class="syntaxkeyword">]<br /></span><span class="syntaxdefault">                end<br />                v </span><span class="syntaxkeyword"><<</span><span class="syntaxdefault"> time </span><span class="syntaxkeyword">*</span><span class="syntaxdefault"> a<br />                a </span><span class="syntaxkeyword">+=</span><span class="syntaxdefault"> 1<br />                new_value </span><span class="syntaxkeyword"><<</span><span class="syntaxdefault"> v<br />            end<br />            keyframes</span><span class="syntaxkeyword">[</span><span class="syntaxdefault">key</span><span class="syntaxkeyword">]</span><span class="syntaxdefault"> </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> new_value</span>

I did it like this in the end as both types of v have time added. Anyway it works which is good! Thanks again.

The empty elements currently are needed to delay certain rotations - like a kick at the end of a run. I have a mechanism to modularise the animation. I want to leave that until later.