Skip to content
Checks collatz-like problems
C Python Makefile
Branch: master
Clone or download
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
.gitignore
Makefile
README.md
collatzl.c
collatzl.py
collatzl_gmp.c
glib.c
glib.h
glib.py
masscheck.py

README.md

CollatzL

Tests modified collatz conjectures (including the original).

Installation

Make sure you have gcc.

Now, clone this repo with:

git clone https://github.com/ChemicalDevelopment/CollatzL.git

change to that directory:

cd CollatzL

compile and test the code:

make

There should be no errors.

If not, please open up an issue.

Usage

This program is used to verify, or counter Collatz-like problems (include original Collatz).

The original collatz conjecture is:

define f(x):
if x is even, f(x) = x / 2
if x is odd, f(x) = 3x+1

And the question is: Does iteration of f(x) f(f(f(...(x))))) eventually reach a cycle, or keep expanding?

We don't know, but all numbers <= 4*10^18 do reach a cycle.

An example of a collatz like function would be:

define f(x):
if x is 0 mod 3, f(x) = x / 3
if x is 1 mod 3, f(x) = 2 * x + 1
if x is 2 mod 3, f(x) = 5 * x + 4 

And again, the question is: Does iteration of f(x) eventually reach a cycle?

To test the original collatz conjecture, run

./collatzl_c.o $MIN $RANGE $MAX_TRIALS 2 1 0 2 3 1 1

It starts at MIN, and runs RANGE numbers each at a max of MAX_TRIALS

The 2 after that tells us we take the number mod 2 (even or odd), and the 1 0 2 tells us to multiply by 1, add 0, and divide by 2

the 3 1 1 tells us to multiply by 3, add 1, and divide by 1, if it is 1 mod 2

./collatzl_c.o 0 1000 1000 2 1 0 2 3 1 1 runs quite quickly, and verifies they all work

To test our other example, the command would be:

./collatzl_c.o 0 1000 1000 3 1 0 3 2 1 1 5 4 1

GMP

There is also a version for GMP, which you can build and test with:

make gmp

The interface is the same as the normal, but the executable is collatzl_gmp.o instead of collatzl_c.o

To run the default command, use:

./collatzl_gmp.o 0 1000 1000 2 1 0 2 3 1 1

And our example would be:

./collatzl_gmp.o 0 1000 1000 3 1 0 3 2 1 1 5 4 1

You can’t perform that action at this time.