The Nineteenth Byte

a sapient human that enjoys doing, focuses on, or studies extensively a technical topic, typically stereotyped as lacking real-life social skills

@Pavel resists urge

A: Sandbox for Proposed Challenges

where are you sandbox bot

it's been 7 minutes

New Sandboxed Posts

Brainfuck Compiler! code-golf Your goal is simple: Compile brainfuck to x86 assembly (NASM style), and do it with as small of a program as possible. You will be able to choose your compiler's input model, as long as the input is brainfuck code and the output is NASM style x86 assembly. The bra...

Pavel

8:04 PM

actually a golfier conditon

Pavel

(7 minutes is faster than average btw)

"someone who waits for the sandbox bot"

Anyways. pls giv feedback on post :p

2 issues

1 that's a bad format for test-cases pick a better one

2 uh how are you going to specify the output nasm?

is it the same output nasm as what you give, or must it just take the same input/output?

it must output assembly NASM can compile

leme make that clearer

8:07 PM

no that's not what I mean

what are the output specifications

must the output file be exactly what your reference implementation outputs?

or must the output nasm just return the same outputs for the same inputs

Must return the same outputs for the same inputs.

So a program that prints hello world must print hello world when compiled.

ok, what about i/o?

can we choose where our output program takes input from?

> The brainfuck code should read from STDIN and output to STDOUT

> You will be able to choose your compiler's input model,

so you can take STDIO, a file, etc etc

How should I format the test cases?

Ok. Thanks

8:13 PM

I made some changes to be it bettre, not sure how to improve from there

anyway yeah you'll need more test cases

Mk. I'll look for some

And maybe make some

8:27 PM

+[<+] should loop forever in brainfuck right? My interpreter just stops and doesn't do much of anything.

quartata

Depends on your interpreter

@moonheart08 If it's unbounded in both directions it should loop forever. But if it's left bounded it should stop

Yea, unbounded is the case i'm thinking of here.

totallyhuman

unless the cells loop around also

quartata

Actually if it wraps around it'll stop eventually

Since the cells overflow

Yeah

8:32 PM

@quartata Only if the IP wraps

If it's truly unbounded, eventually it'll just run out of memory and crash

quartata

That's what I meant, if the tape wraps around

Ah, ok

9:05 PM

I've found this 'gem'

it's only specifications tho

ASCII-only

10:03 PM

@Riker someone should totally write a graphical interpreter for this

New Main Posts

10:14 PM

Q: Levi-Civita symbol

The three-dimensional Levi-Civita symbol is a function f taking triples of numbers (i,j,k) each in {1,2,3}, to {-1,0,1}, defined as: f(i,j,k) = 0 when i,j,k are not distinct, i.e. i=j or j=k or k=i f(i,j,k) = 1 when (i,j,k) is a cyclic shift of (1,2,3), that is one of (1,2,3), (2,3,1), (3,1,2)....

Destructible Lemon

@Pavel being a nerd

is it possible to make a language which, without a special command, is turing incomplete, but given the special command to solve the halting problem for the turing incomplete variant lacking the stated command, becomes turing complete?

o_O

Destructible Lemon

is that really that confusing?

Downgoat

yes

Destructible Lemon

let me rephrase

consider a language which will be referred to as x, because i can't think of something else

language x is turing incomplete

consider the language x' which is x with a command that takes a program written in x, and returns whether it halts

is there such an x such that x' is TC

obviously not a rigorous question because it's subjective in some ways

like, it'd be possible to make it so that some commands aren't accessible until you solve the halting problem or something...

New Main Posts

10:50 PM

Q: Work out root(x, n)

Given 0<x<10106 and 0<n<106, work out x(1/n) under 15 seconds(TIO or your computer), 1GB memory. You can assume the result is integer smaller than 50000. Shortest code in bytes in each language win. Sample: x n result 121 2 11 123 1 123 1024 10 2

code-golf math

11:05 PM

Anyone know what the formula for standard deviation of a sampling distribution of variance is? I'm having trouble finding it online

@Adám Probably don't ask on MathOverflow.

Adám

@Zacharý I think you can find it on

Standard deviation

In statistics, the standard deviation (SD, also represented by the Greek letter sigma σ or the Latin letter s) is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A low standard deviation indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values. The standard deviation of a random variable, statistical population, data set, or probability distribution is the square root of its variance. It i...

(about a third way down)

I can't find anything but a note about the standard deviation of a sampling distribution of standard deviation following chi-distribution. Can you show me which section you're looking on>

Stats terminology is weird.

Downgoat

ppcg-v2: do you like this over the previous design?

ASCII-only

wow looks very nice

but idk what previous design is

I found 2*sigma^4/(n-1) on the page on variance, but that seems wrong.

Downgoat

11:23 PM

@ASCII-only this is old designe