jstirrell posted:

The problem is that it doesn't compile currently which I think is due to some syntax error at the end of the code which I can't figure out, but what worries me more is that I still feel like I have no clue if I even have a decent structure for the program I'm trying to write, or where I'm really heading with this. Anyone have any suggestions? What am I doing right? What is wrong? Any general tips for struggling self-teaching noobs like myself? Also, I'm trying to get the general structure of the code down so I realize some of the non-critical details (ie elifs) are missing.

Sorry for the wall of code, should I not be posting huge general questions here? I'm just kind of really lost.

tripwire posted:

Can someone help me get this stupid mona lisa approximator thing working? I've given up on trying anything remotely fancy and just mutate a list of floats which are the values used to draw triangles on a cairo canvas.

I'm using numpy to add up the squared difference between color values on each pixel and square rooting that to get the root mean square error.

For some reason my picture ALWAYS converges to some ridiculous garbage in a short amount of time which is frustrating, because it could mean either that my genetic algorithm is hosed up somehow (maybe I made a mistake with passing by reference vs passing by value somewhere?) or that the logic for my root mean square error code is hosed up.

Can anyone help me out?

Scaevolus posted:

I'm way too tired to try to read this, but the original didn't use RMS, it used a simple sum of differences. Perhaps that causes garbage convergence?

Also it seems like after a few generations every genome has the exact same fitness, which seems to be an error.

I doubt the effectiveness of crossover between genomes in this problem domain-- stair-climbing seems better.

tripwire posted:

Can someone help me get this stupid mona lisa approximator thing working? I've given up on trying anything remotely fancy and just mutate a list of floats which are the values used to draw triangles on a cairo canvas.

I'm using numpy to add up the squared difference between color values on each pixel and square rooting that to get the root mean square error.

For some reason my picture ALWAYS converges to some ridiculous garbage in a short amount of time which is frustrating, because it could mean either that my genetic algorithm is hosed up somehow (maybe I made a mistake with passing by reference vs passing by value somewhere?) or that the logic for my root mean square error code is hosed up.

Can anyone help me out?

Swanson Broth posted:

I am new to Python and Pygame (and coding). In what module/function should I be looking in order to draw a line at exactly a 45 degree angle from a point?

tripwire posted:

code:

...
    def _inherit_genes(child, parents):
        if len(parents) > 1: #perform crossover
            for i in xrange(100):
                child._genes.extend(random.choice((parent1,parent2))._genes[i*10:i*10+10])
        else: #just a clone
            child._genes.extend(parents[0]._genes)
...

Jo posted:

It could be me, but I thought when inheriting genes, one would select a random splice point and then take all material up to said splice from one parent and all material from the splice from the other parent. Here, it looks as if you're alternating your selection of chunks of genes.

I.E. Instead of...
P1: [ABCDEFG]
P2: [HIJKLMN]
CH: [ABCKLMN]

You're doing...
P1: [ABCDEFG]
P2: [HIJKLMN]
CH: [ABJKLFG]

Kire posted:

I'm trying to use Tkinter to get a single line of input, then turn that line into a tuple, parsed by the commas that the user enters.

code:

from Tkinter import *

portfolio = []

class MyDialog:

    def __init__(self, parent):

        top = self.top = Toplevel(parent)

        Label(top, text="Portfolio: Date, Purchase Price, Ticker,\
 Current Price:").pack()

        self.e = Entry(top)
        self.e.pack(padx=5)

        b = Button(top, text="Process", command=self.ok)
        b.pack(pady=5)

    def ok(self):

        portfolio = [(self.e.get())]

        self.top.destroy()
        for item in portfolio:
            date = item[0]
            purchase = item[1]
            ticker = item[2]
            current = item[3]
            print 'Date:', date
            print 'Purchase price:', purchase
            print 'Ticker symbol:', ticker
            print 'Current price:', current
        
root = Tk()
root.update()
d = MyDialog(root)
root.wait_window(d.top)

If I input "Jan, 45.0, EK, 55.5" in the popup window then it just spits out "J" "a" "n" "," for the Date, Purchase Price, etc. Any ideas?

UnNethertrash posted:

Ninja edit: My question, of course, is why is his code so much faster when they seem identical?

functional posted:

I read his code. After the second time through it was clear to me what he was doing. Very straightforward, simply accomplished. I've tried to read through your code four or five times now. Each time I give up because the spaghetti logic is simply too much. I have a question for you and a recommendation.

Question: If your code is running so much slower than this person's code, are your if statements really improvements? If you determine that they're not improvements of the most important type, perhaps you could go back to before you added them in, and optimize there.

Recommendation: If you were truly interested in improving your ability, rather than continue on solving each of these Euler problems, none of which will pose any real challenge to you, you would start over at the beginning and play golf with each of the problems. What is the shortest amount of code you can solve each of the problems in? I think this exercise will do you a lot more good.

tripwire posted:

Habnabit posted:

Note that a leading __ does not make private attributes. It invokes name mangling, which is most definitely not what you want. It's only useful if you're trying to prevent naming conflicts in subclasses. If you're trying to annotate an attribute as private, use a better lexical convention: a leading _. Everyone knows what you mean and it doesn't mangle names.

tripwire posted:

Thanks for the heads up. I knew I read before that you were supposed to use just one underscore for private names but apparently I'm an idiot and forgot. Using it on the functions i want to override is ok though right? I based most of this off of a neuroevolution package I used to use because I had no idea where to start so theres still some boneheaded artifacts of my unthinking copy+pasting in there.

My population class has its own iteration and comparator methods though, in that case double underscores are correct right? Like if you are trying to override a builtin function?

Habnabit posted:

Yes, name mangling only takes effect if there's a leading __ with no trailing __. So, __iter__ et al. are safe.

Regarding your code itself, I haven't used (or even installed) cairo myself, so I unfortunately can't be much help there.

e: Oh, I missed a part of your question. No, you don't want to use name mangling if you want to override the methods. In fact, name mangling is intended to prevent things from being (implicitly) overridden.

tripwire posted:

Whats the idea of that? I thought it was so then when you call len() on a population object it would use the __len__ definition provided above.

tbradshaw posted:

dorkanoid posted:

code:

self.genome = [gene + random.gauss(0,1) for gene in self.genome]

...should work

tripwire posted:

How do you build a list comprehension that would mimic the functionality of going through every gene in the genome and conditionally applying a mutation if random.random() is greater or less than than some threshold value?
I can get as far as

code:

self.genome = [gene + random.gauss(0,1) for gene in self.genome if r() < threshold]

but that obviously won't work because whenever that last if statement is not true a gene will get cut from the genome.
Using a lambda and map I guess?

Bonus posted:

I don't see what's wrong with this:

code:

self.genome = [gene + random.gauss(0,1) if random.random() < threshold else gene for gene in self.genome]

if you don't want the gene variable leaking out, you can do

code:

self.genome = list(gene + random.gauss(0,1) if random.random() < threshold else gene for gene in self.genome)

because generator expressions don't leak out variables whereas list comprehensions do, although this is fixed in Py3k.

Also, just doing map(foo, self.genome) won't do a thing because map doesn't modify the list, it just returns a new copy, so you have to do self.genome = map(foo, self.genome)

WickedMetalHead posted:

twisted has a lot of non blocking type stuff and has a dns specific implementations if i recall correctly.

Habnabit posted:

Seconding this. Don't bother with threads when twisted provides an async DNS resolver already.

tripwire posted:

Has anyone used the multiprocessing module before? I'm trying to use a pool to split up the work in my mona lisa triangle mover thing but it doesn't look like you can call it from an instance of a class and point to an instance method (it raises a pickle error, 'can't pickle instancemethod' or something like that. Do I have to make it use a global function? Is there some idiom or pattern for doing this?

tripwire posted:

Has anyone used the multiprocessing module before? I'm trying to use a pool to split up the work in my mona lisa triangle mover thing but it doesn't look like you can call it from an instance of a class and point to an instance method (it raises a pickle error, 'can't pickle instancemethod' or something like that. Do I have to make it use a global function? Is there some idiom or pattern for doing this?