Optimization Tips

Jernej Vidmar

Hi guys,

I have just found out that converting String to Length directly is up to 13x slower in comparision to converting it to Float first and only then to Length...


def string_to_length_conversion(iterations=100_000)
	a=0
	t1=Time.now.to_f
	iterations.times do
		# convert to Length directly
		a = '5,0'.to_l
	end
	t2=Time.now.to_f
	puts "Conversion to Length directly took #{t2-t1} sec, a=#{a}"

	t1=Time.now.to_f
	iterations.times do
		# convert to Float, then apply units (meters in this case) and set to Length
		a = '5,0'.to_f.m.to_l
	end
	t2=Time.now.to_f
	puts "Conversion to Length via Float took #{t2-t1} sec, a=#{a}"
end
#Conversion to Length directly took 1.84500002861023 sec, a=5,00m
#Conversion to Length via Float took 0.14300012588501 sec, a=5,00m

thomthom

@unknownuser said:

I have just found out that converting String to Length directly is up to 13x slower in comparision to converting it to Float first and only then to Length...

That is useful to know. But that assumes one has a string with only a numeral.
String.to_l will allow you to covert strings such as '20m' and '20mm'. With out any length unit indication in the string it will assume the length is in the unit of the current model.

TIG

BUT remember that .to_l parses any 'units' text to work out the actual value into inches...
So "1.0m".to_l >>> 39.3700787401575"
or "1'".to_l >>> 12"
BUT
"1.0m".to_f.to_l >>> 1.0"
and "1'".to_f.to_l >>> 1"
therefore you may as well miss out the second method .to_l as
"1.0m".to_f >>> 1.0
and "1'".to_f >>> 1
i.e. as a 'raw number'... AND 'raw numbers' are assumed to be in inches anyway == 1.0"...
Also .to_l and .to_f work differently if there is no 'unit' suffix...
If you have mm set as your current units then
"1".to_l >>> 0.0393700787401575 (inches)
but "1".to_f >>> [ruby:3h6c8mbs]1.0[/ruby:3h6c8mbs] (float/number),
and with inches as the current units
"1".to_l >>> [ruby:3h6c8mbs]1[/ruby:3h6c8mbs] (inch)
SO if you have an input that might be in anything other than inches and might have units in its string you do need to use .to_l or you risk returning a wrong value...

Dan Rathbun

+ vs << vs "#{}"

Benchmark Test (at ruby-talk-google)
String concatenation in ruby

thomthom

` t=Time.now; 1000000.times{ 3**2 }; puts Time.now - t
0.948
nil

t=Time.now; 1000000.times{ 3*3 }; puts Time.now - t
0.216
nil`

thomthom

@unknownuser said:

does the whole line have to be in c? im trying to map this out---
%(#0040FF)[]

What do you mean? Are you making a C Extension?

thomthom

@unknownuser said:

THOM THOM WHAT KIND OF SCRIPTING LANGUAGE IS RUBY???????

Sorry, but I don't understand what 'kind' you mean. Can you elaborate a bit more?

And please, do not use all caps. It's hard to read and it's considered bad manners.

Dan Rathbun

Ruby is a 100% Object-Oriented Interpreted Scripting Language.

See: "Ruby Newbie's Guide to Getting Started"

Dan Rathbun

@unknownuser said:

does the whole line have to be in c? im trying to map this out---

If you are new to Ruby... learn Ruby scripting, don't worry about it's C source code, you'll just confuse yourself. (The Ruby interpreter engine just happens to be written in C and compiled. You don't need to know C unless your involved with actually maintaining / updating the Ruby Core libraries. This has noting to do with using Ruby or writing Ruby scripts, or using Sketchup.)

thomthom

i += 1 vs i = i.next

i=0; t=Time.now; 10000000.times { i+=1 }; Time.now-t
2.045

i=0; t=Time.now; 10000000.times { i=i.next }; Time.now-t
1.682

TIG

@thomthom said:

i += 1 vs i = i.next
i=0; t=Time.now; 10000000.times { i+=1 }; Time.now-t
2.045
i=0; t=Time.now; 10000000.times { i=i.next }; Time.now-t
1.682

So avoid i='0'; t=Time.now; 10000000.times { i.next! }; Time.now-t
~8.300

thomthom

@thomthom said:

That would mean it's not the each loop itself that's slow - but the creation of variables.

range = (0..10000000)

t=Time.now; range.each { |i| x = i + 1 }; Time.now-t
3.402

t=Time.now; x=0; range.each { |i| x = i + 1 }; Time.now-t
2.848

t=Time.now; x=0; i=0; range.each { |i| x = i + 1 }; Time.now-t
2.39

t=Time.now; for j in range; y = j + 1; end; Time.now-t
2.196

t=Time.now; y=0; for j in range; y = j + 1; end; Time.now-t
2.186

If one has to use blocks, init the variables you use inside the block first.

dany67300

I have read all you optimisation tips and tried them, but nothing seems to change the speed creation of my objects. I'm using Sketchup 8 to create dominos described by a picture. To create the dominos, I tried the add_face method and the fill_from_mesh, but the times are exactly the same. It takes me about 2 s to create 400 pieces, and it's growing exponentially. With 600 pieces -> 7s, 1200 pcs -> 50s...
Is it normal to take so much time ? Each domino is created in his own group for the moment, but it doesn't change if I create them directly in my scene.

TIG

@dany67300 said:

I have read all you optimization tips and tried them, but nothing seems to change the speed creation of my objects. I'm using Sketchup 8 to create dominoes described by a picture. To create the dominoes, I tried the add_face method and the fill_from_mesh, but the times are exactly the same. It takes me about 2 s to create 400 pieces, and it's growing exponentially. With 600 pieces -> 7s, 1200 pces -> 50s...
Is it normal to take so much time ? Each domino is created in his own group for the moment, but it doesn't change if I create them directly in my scene.

Since all dominoes are fixed by there number pattern, why not make the set as separate SKPs with common origins.
Then load them into the model when you run the script - no need to make geometry at all - and ' entities.add_instance(defn, trans)' of them as needed - the transformation used when adding determines the location and rotation.
Because they are each component instances you can swap one type for another as you wish - in code instance.definition=xxxx ...
IF you only have one simple block domino make one definition and add_instances of that multiple times... You can apply different materials separately to each instance...

dany67300

I hadn't seen that i could put a different material to each instance of a same defintion
thanks a lot ! it works very well

bentleykfrog

@dany67300 said:

It takes me about 2 s to create 400 pieces, and it's growing exponentially. With 600 pieces -> 7s, 1200 pcs -> 50s...
Is it normal to take so much time ? Each domino is created in his own group for the moment, but it doesn't change if I create them directly in my scene.

I've noticed that sketchup slows down greatly once the number of groups in the current tier is greater than 1000 on my machine. Does your script speed up if the geometry is written straight to Sketchup.active_model.entities?

thomthom

@bentleykfrog said:

@dany67300 said:

It takes me about 2 s to create 400 pieces, and it's growing exponentially. With 600 pieces -> 7s, 1200 pcs -> 50s...
Is it normal to take so much time ? Each domino is created in his own group for the moment, but it doesn't change if I create them directly in my scene.

I've noticed that sketchup slows down greatly once the number of groups in the current tier is greater than 1000 on my machine. Does your script speed up if the geometry is written straight to Sketchup.active_model.entities?

Adding entities to SketchUp slows down in direct proportion to how many existing entities there is in the entities collection you add to.

sm4rt

Well I got a situation !!

C:\>ruby test.rb range = (0..90000000) t=Time.now; x=0; i=0; range.each { |i| x = 0b0011_1100<<2 }; Time.now-t 13.156753 t=Time.now; x=0; i=0; range.each { |i| x = 60*4 }; Time.now-t 10.400594

just a no sens !!!
Really a human oriented language

Dan Rathbun

The for loop should be faster, try:

` t = Time.now
for i in range do

code here

end
puts Time.now - t`

sm4rt

Was talking about shifting binary number is longer then the same "base 10" arithmetic operation...

Which is no sense in processor calculation.
Try the same comparison in ASM, C++, PHP etc. and look the result^^

But in this case I think it's because x = 0b0011_1100<<2 affect the decimal number of the binary one to x variable so the number of edge clock needed is greater... IMO

Edit: And for loop isn't for me Result-for-each-variables.txt
here is my results of the test that ThomThom put above to prove that for loop is better then each one and that declaring variable before is faster too but it's still not true for my equipment...
(Ruby 1.9.2-p180 / Windows 7 64 bit / Intel Core i3 M 350 2.27GHz)

So I think that these optimizations depend of many variables....(versions of Ruby/Sketchup) Even if some will still be true in the future...