Stack Overflow
Stack Overflow

Questions tagged [bijection]

In mathematics, a function is a bijection, or is bijective, if it is both injective and surjective.

47 questions
0
votes
0 answers

Usage of a BlockwiseBijector in MCMC?

I want to run MCMC with 203 parameters and want to apply different bijectors to the first, second, third and the rest of the parameters separately. How do I do this without running into errors? I am currently using a Blockwise-Bijector with…
tobnie
  • 3
  • 3
0
votes
1 answer

Set of functions using Function interface

Let there be a set A = {1,2,3}. The goal is to compute all bijections on AxA. It should be of type Set> so that in the driver code, we can use the "apply" function. I have tried a lot and have also figured out that the bijections will…
Anurag Singla
  • 23
  • 7
0
votes
2 answers

Construct a bijective function to map arbitrary integer from [1, n] to [1, n] randomly

I want to construct a bijective function f(k, n, seed) from [1,n] to [1,n] where 1<=k<=n and 1<=f(k, n, seed)<=n for each given seed and n. The function actually should return a value from a random permutation of 1,2,...,n. The randomness is decided…
Daniel
  • 1,783
  • 2
  • 15
  • 25
0
votes
0 answers

Represent a 1-1 relationship

I have come to a need to represent a one to one relationship in python. The easiest thing to do is have a list of tuples. [(thing_one, thing_two]. But this would get you O(N) translation/deletion/insertion time. Not ideal. Next you could use two…
Mitch
  • 3,342
  • 2
  • 21
  • 31
0
votes
2 answers

Short URL with unique but random generated string?

So I have been trying to build a URL shortner but I am unable to generate unique but random strings. I have look everywhere for a solution but couldn't find one thus posting it here. I have a table in which I get auto-generated sequential primary…
NewbieProgrammer
  • 874
  • 2
  • 18
  • 50
0
votes
1 answer

Removing bijective columns automatically from the data frame identified using whichAreBijection command from dataPreparation package using r

I am having trouble doing a simple task: Say I use these libraries and have this data frame: library(tidyverse) library(dataPreparation) df <- data.frame(col1 = 1, col2 = rnorm(1e1), col3 = sample(c(1, 2), 1e1, replace = TRUE)) df$col4 <-…
Ray
  • 321
  • 2
  • 12
0
votes
0 answers

Retrieve schema from parquet-avro messages pulled from kafka

Using samples from various sources I have written this method (relevant section shown below) where I am pulling parquet-avro messages from kafka for a test application. Based on the code I could find to get this working (some of which is from…
chrismead
  • 2,163
  • 3
  • 24
  • 36
0
votes
2 answers

Is there a bijection between any distinct 4 4-bits strings and all the 2-bits strings?

Let me give you an example, let's consider the strings: 1000 0101 0111 0000 and the full range of 2-bits strings: 00 01 10 11 i am wondering if there is a function that has an inverse and that maps the 4 4-bits string to the 2-bits strings.
abebat
  • 11
0
votes
1 answer

Serializing generic avro records as an Array[Byte] keeps the schema in the object

Situation I'm currently writing a consumer/producer using AVRO and a schema repository. From what I gather My options for serializing this data is either use the Confluent's avro serializer, or go with Twitter's Bijection. It seemed Bijection looked…
Havnar
  • 2,558
  • 7
  • 33
  • 62
0
votes
2 answers

Bijective relations between ranges and some constants?

Please, move this question to Code Review -area. It is better suited there because I know the code below is junk and I wanted critical feedback to complete rewrite. How can I write the set-to-constants relations in Python? So if A in a range, then…
hhh
  • 50,788
  • 62
  • 179
  • 282
0
votes
2 answers

convert a string into something reversible, in Java

I have a lot of urls that serve as keys in a HBase table. Since they "all" start by http://, Hbase puts them in the same node. Thus I end with a node at +100% and the other idle. So, I need to map the url to something hash-like, but reversible. Is…
Costin
  • 2,699
  • 5
  • 25
  • 43
0
votes
3 answers

What function pseudo-randomly reorders exactly N items?

Having natural numbers 1 to N (N is around 1e7), I dream of function that would reorder the set in a way, defined by a rather short set of parameters, compared to the range of values. For N = 2^i - 1 this can be just bit reordering, thus, a set of…
Serge
  • 1,531
  • 2
  • 21
  • 44
0
votes
1 answer

Index-based access on Matrix-like structure in C++

I have a mapping Nx2 between two set of encodings (not relevant: Unicode and GB18030) under this format: Warning: huge XML, don't open if having slow…
Alex
  • 340
  • 4
  • 17
0
votes
0 answers

Bijective Single Type Collection

Are there any bijective data structures that use only one type such that if a -> b then b -> a where a and b are of the same type? I have looked at BiMap of Guava and BidiMap of Apache Commons but both require getting the inverse of the map to check…
flungo
  • 1,050
  • 1
  • 7
  • 21
0
votes
1 answer

JBoss Seam - Can't @In annotations be used at the same time with accessor methods for different properties?

I generated a new form using sean-gen (seam new-form) and added another field to it using an @In annotation: @Stateful @Name("dummy") public class DummyBean implements Dummy { @Logger private Log log; @In StatusMessages statusMessages; …
Cleber Goncalves
  • 1,936
  • 3
  • 18
  • 23
1 2
3
4