## Search found 202 matches

Tue Mar 26, 2013 4:59 pm UTC
Forum: Mathematics
Topic: [HOMEWORK] Statistics Uniform distribution
Replies: 1
Views: 2379

### [HOMEWORK] Statistics Uniform distribution

1. A bus arrives at a bus stop at a uniformly distributed time over the interval 0 to 1 hour. A passenger also arrives at the bus stop at a uniformly distributed time over the interval 0 to 1 hour. Assume that the arrival times of the bus and passenger are independent of one another and that the pa...
Mon Jan 14, 2013 4:36 pm UTC
Forum: Mathematics
Topic: [HOMEWORK] Arccot problem
Replies: 3
Views: 1811

### [HOMEWORK] Arccot problem

Im doing homework, but one problem just wont come to me.

I have to prove:

arccot(x)-arccot(y)= arccot((x-y)/1+xy)

But ive seen on the interwebs that its not 1+xy but 1-xy. Thing is, I don't even know where to start. Not asking for the solution. But I just cant get this to work.
Sun Dec 16, 2012 1:10 pm UTC
Forum: Forum Games
Topic: Can you produce [X] in less than 15 seconds?
Replies: 7748
Views: 783529

### Re: Can you produce [X] in less than 15 seconds?

could only find delicious chocotoffs, and I ate one, that was enough.

Something in the shape of sinus wave.
Tue Oct 23, 2012 2:50 pm UTC
Forum: Mathematics
Topic: ice cream cone probability (homework)
Replies: 8
Views: 3148

### Re: ice cream cone probability (homework)

I am not allowed to learn this via function, I have to write everything out so that is no use for me. But thanks anyway, I was moreover concerned with understanding what is being done here.
Mon Oct 22, 2012 7:37 pm UTC
Forum: Mathematics
Topic: ice cream cone probability (homework)
Replies: 8
Views: 3148

### Re: ice cream cone probability (homework)

Or put it this way: when you lay out the full set of permutations (order matters) + duplicates, you want to remove the possible combinations (order doesn't matter) on the discrete symbols (without duplicates), because they'll come up twice. So if you have a calculator with nCr and nPr buttons: 10P2...
Mon Oct 22, 2012 7:24 pm UTC
Forum: Mathematics
Topic: ice cream cone probability (homework)
Replies: 8
Views: 3148

### Re: ice cream cone probability (homework)

I'm studying for a midterm statistics (yay) and I'm stuck on one question : in an ice cream parlour you can have ice cream cones with 1,2 or 3 scoops of ice cream. You can choose from 10 flavours, but you can also have multiple scoops of the same flavour. The order in which the scoops are put on th...
Mon Oct 22, 2012 7:07 pm UTC
Forum: Mathematics
Topic: ice cream cone probability (homework)
Replies: 8
Views: 3148

### ice cream cone probability (homework)

I'm studying for a midterm statistics (yay) and I'm stuck on one question : in an ice cream parlour you can have ice cream cones with 1,2 or 3 scoops of ice cream. You can choose from 10 flavours, but you can also have multiple scoops of the same flavour. The order in which the scoops are put on the...
Mon Oct 15, 2012 12:06 pm UTC
Forum: Mathematics
Topic: How to summarize math homework
Replies: 10
Views: 2515

### Re: How to summarize math homework

Going over your notes and summarising them is largely about forcing you to get the ideas sorted in your head, and helping you remember them. I would definitely recommend good old-fashioned pen and paper for this as it stops you being distracted by formatting issues and other off-topic concerns. As ...
Sun Oct 14, 2012 6:59 pm UTC
Forum: Mathematics
Topic: How to summarize math homework
Replies: 10
Views: 2515

### Re: How to summarize math homework

ill try the lyx, so i can get used to writing latex and try the gui. I just want it to look nice / not take ages to write up.
Sun Oct 14, 2012 4:15 pm UTC
Forum: Mathematics
Topic: How to summarize math homework
Replies: 10
Views: 2515

### How to summarize math homework

Im doing my first year of econometrics and I wish to summarize and archive all my lectures in a good, clean and concise way. But how? Doing equations in Word is cumbersome and doing everything in LaTeX seems a world of pain. Any good tools out there that help with this sort of thing? I like everythi...
Thu Oct 11, 2012 5:31 am UTC
Forum: Mathematics
Topic: Normal distribution and the error function
Replies: 5
Views: 2968

### Re: Normal distribution and the error function

As far as I know, there isn't a simple way of computing the normal cdf by hand. Most statistics textbooks (at least all the ones I've come across) have very helpful tables in the appendices, such as this one. It is a good skill to be able to normalize a given distribution so you can use these sorts...
Thu Oct 11, 2012 5:18 am UTC
Forum: Mathematics
Topic: Homework Looks like partial integration, but isnt?
Replies: 4
Views: 2107

### Re: Homework Looks like partial integration, but isnt?

Ah yes, i see. I've used 4-x^2 now, because the du is easier. edit this is what I used, as you said. I just wrote it down wrongly. I've never had the 'df/dx' notation in my life. I sorta know what it means, but can i just assume that dx = 1 ? and so if du = 1, i can say du = dx so i can just replace...
Wed Oct 10, 2012 1:43 pm UTC
Forum: Mathematics
Topic: Homework Looks like partial integration, but isnt?
Replies: 4
Views: 2107

### Re: Homework Looks like partial integration, but isnt?

just an update on what i've done:

I've used u = root(4-x^2) and used that in the equation where du = -2x * dx . so the remaning dx we had is -(1/2)du = dx, so our new integral is:

-(1/2) integral( root(u) du )
Wed Oct 10, 2012 1:10 pm UTC
Forum: Mathematics
Topic: Homework Looks like partial integration, but isnt?
Replies: 4
Views: 2107

### Homework Looks like partial integration, but isnt?

this is homework . Well it isn't but I'm studying for a precalculus test. I'm having trouble witht he following The integral from o to 1, x * root(4-x^2) Now my first thought would be: partial integration (yay) but my teacher says I need to see it. Saying there is no rule for it. I just can't get my...
Fri May 18, 2012 8:37 am UTC
Forum: Coding
Topic: htaccess is killing me.
Replies: 1
Views: 1450

### htaccess is killing me.

RIGHT. I'm having the biggest headache ever. htaccess is acting up. Here's my code at the moment: #send to www RewriteCond %{HTTP_HOST} !^localhost\$ RewriteCond %{HTTP_HOST} !^www\.funzors\.com\$ RewriteCond %{SCRIPT_URI} !^static\.funzors\.com/uploads/(.*)\$ RewriteRule ^(.*)\$ http://www.funzors.com/...
Thu Mar 01, 2012 10:27 pm UTC
Topic: 1023: "Late-Night BS"
Replies: 73
Views: 20165

### Re: 1023: "Late-Night PBS"

It should be an Austrian basement, I believe... Dutch basements are just full of weed and old stolen bicycle parts :) There is no mention of a basement in the comic. Anne Frank was captured living in a secret room behind a bookshelf in a Dutch apartment (and, like many Dutch Jews, deported to a con...
Tue Jan 17, 2012 10:24 pm UTC
Forum: Coding
Topic: Analyzing Social Media Data Pertaining to Bitcoin
Replies: 5
Views: 2836

### Re: Analyzing Social Media Data Pertaining to Bitcoin

lol, currency not backed up by anything. Sure thing bro.
Sat Jan 07, 2012 10:48 pm UTC
Forum: Coding
Topic: Terrain Rendering
Replies: 14
Views: 2917

### Re: Terrain Rendering

This may be entirely the wrong forum, but: How should I render the terrain in the game engine I'm programming? Rendering terrain from a heightmap is simple and easy to optimize, but I really don't like that I can't implement cliffs or overhangs or caves. Should I use voxels? Is there another option...
Sun Jan 01, 2012 2:25 pm UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### Re: image comparison

I would boil down the image into a series of Fourier coefficients for a few different paths and a few different frequencies. You'd then get a manageable series of numbers you can use to assess similarity (these numbers of course need only be calculated once per image). Kind sir, I know my maths, bu...
Sat Dec 31, 2011 9:56 pm UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### Re: image comparison

I would boil down the image into a series of Fourier coefficients for a few different paths and a few different frequencies. You'd then get a manageable series of numbers you can use to assess similarity (these numbers of course need only be calculated once per image). Kind sir, I know my maths, bu...
Sat Dec 31, 2011 2:23 pm UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### Re: image comparison

well steax, I've actually implemented this algorithm. It's sort of like an md5 hash, but you can compare images. Now i'm using the hamming distance to find out (while uploading) if there are any similar images, this takes 0.0002 seconds for 500 images. The actual first hash takes a long time (0.5 se...
Fri Dec 30, 2011 2:53 pm UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### Re: image comparison

Nearest neighbor searches in high dimensional spaces can be done by using Locality-sensitive hashing . isn't that probably gonna be overkill? I'm doing the same right now. The actual hashing can take about 1/2 seconds, I don't mind that. But the searching has to be fast. I'm already planning on usi...
Fri Dec 30, 2011 2:24 pm UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### Re: image comparison

well this algorithm will also give me the same 'hash' with same images, so that's already done. But this one also takes into account different sizes, ratios and slight alterations (I did a test with a man, and the same man with a beard. it gave me a '3' and with an entirely different picture it gave...
Fri Dec 30, 2011 2:45 am UTC
Forum: Coding
Topic: image comparison
Replies: 18
Views: 3250

### image comparison

So. I've been extending my image hosting/funny image hosting site and I found a way to keep duplicates/reposts out of the game. I've found an algorithm which makes a footprint of the image (not a hash, which only works for duplicates which this algorithm also handles). it produces a string such as t...
Tue Dec 20, 2011 7:45 am UTC
Forum: Coding
Topic: Why should I use get and set for my class methods?
Replies: 14
Views: 4325

### Re: Why should I use get and set for my class methods?

The best rule of thumb is that whatever you're making, someone's already had to do it before. I abuse (modular) libraries to their limits. Go browse round them, take libraries you like, throw them somewhere in your server, and include them on-demand. Don't copy bits and pieces for each project. Jus...
Mon Dec 19, 2011 5:09 pm UTC
Forum: Coding
Topic: Why should I use get and set for my class methods?
Replies: 14
Views: 4325

### Re: Why should I use get and set for my class methods?

Now The other solution there is always to write your comparrisons with a literal the other way round; if ("foo" == \$file->contents) That way, it's again an error if you omit an equals sign. Or it should be, in most sensible languages - but then it is php we're talking about . True, true. M...
Mon Dec 19, 2011 6:37 am UTC
Forum: Coding
Topic: Why should I use get and set for my class methods?
Replies: 14
Views: 4325

### Re: Why should I use get and set for my class methods?

Thanks guys, I think I understand it. The class should be more closed off and simple things such as get_area() or \$user->get_profile() or something should be done via the class itself, not outside of the class which defeats the purpose of having a class. Or am I misreading things here? BTW speaking ...
Sat Dec 17, 2011 10:23 am UTC
Forum: Coding
Topic: Why should I use get and set for my class methods?
Replies: 14
Views: 4325

### Why should I use get and set for my class methods?

But I'm having trouble seeing why I should use get_videowidth while i can also use \$media->width?
Wed Dec 14, 2011 12:18 am UTC
Forum: Coding
Topic: I need help with c++
Replies: 6
Views: 2564

### Re: I need help with c++

Indentation, use [code ] [ /code] tags and if you're gonna be working with international coders, or want to share it with the world: use english functions/methods (I don't know c++).

Else: again, indentation.
Sun Dec 11, 2011 7:39 pm UTC
Forum: Coding
Topic: How difficult would this be to create?
Replies: 11
Views: 2644

### Re: How difficult would this be to create?

I myself have a site like that. If you wish to maintain it properly and not have to work 30 hours in a week just keep it up, you'll have to learn a -lot- to get this going. Interesting. What does this number look like if I do it right the first time? . A long ass time. That's what. Seriously. If yo...
Sun Dec 11, 2011 7:18 pm UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

Robert'); DROP TABLE *; wrote:Well, is there a lot of processing going on on upload/delete? That would seem to be the ideal place to do it.

I'll probably be doing that, with a weekly CRON update. Oh my, my spaghetti code is turning against me
Sun Dec 11, 2011 3:49 pm UTC
Forum: Coding
Topic: How difficult would this be to create?
Replies: 11
Views: 2644

### Re: How difficult would this be to create?

I myself have a site like that. If you wish to maintain it properly and not have to work 30 hours in a week just keep it up, you'll have to learn a -lot- to get this going.

IF you have the motivation, by all means go for it. If not, pay someone for it.
Sun Dec 11, 2011 12:31 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

Your counts seem to be off, but I'm not entirely sure how. For instance, "WTF?" returns 8 links, but tells me, "1 video, 4 pictures" Yes that's because it isnt updated automaticlly, it's done via a CRON every day. I'd figure that's more efficient than doing counts every time som...
Sun Dec 11, 2011 12:16 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

Alright, as a progress report: I've finished the categories via the three table method. For a many-to-many link And the tags are still one table. Maybe later I'll try and make that many-to-many.

As for what the result is: http://www.funzors.com/categories/
Mon Nov 14, 2011 6:22 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

When I was deciding on a tagging system for an old web app, I stumbled across this really useful article which gave an overview over the various schemas. It's old, but still relevant. I've actually read that one Steax, but I was confused as to what I was going to use, the three table approach, whic...
Sun Nov 13, 2011 10:27 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

i search through them with a fulltext search...
Sat Nov 12, 2011 11:08 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Re: Database structure problem with tags, categories

Yeah, having a "tags" column in the "media" table is going to make querying a bitch, not to mention that it's poor relational design. Your best option is to have a separate table with a "media_id" column FKed to the "media" table, and a "type" (or &...
Fri Nov 11, 2011 11:49 am UTC
Forum: Coding
Topic: Database structure problem with tags, categories
Replies: 19
Views: 4670

### Database structure problem with tags, categories

Ok, I'll keep it short. I have a website with a problem regarding my database. It's mostly about the structure in my database. I have pictures and videos on my website I want them to be easily categorized and searchable. The pictures and videos are structured as such: ⋅ Media (all informat...
Tue Oct 25, 2011 4:48 pm UTC
Forum: Coding
Topic: Bounce rate & general tips
Replies: 30
Views: 6061

### Re: Bounce rate & general tips

Do you mean row or column?
Sat Oct 22, 2011 2:45 pm UTC
Forum: Coding
Topic: top picture of the day
Replies: 17
Views: 2561

### Re: top picture of the day

My rule of thumb is generally that minor performance benefits by structuring your data in one way or another can be disregarded for simplicity and something that makes sense to the developer. Your setup looks fine, especially given that the two kinds share some parameters. Just make sure you're onl...