'There is no apparent reason why one number is prime and another not.
On the contrary, upon looking at these numbers one has the feeling of being
in the presence of one of the inexplicable secrets of creation.'
This is a tool for visualizing and exploring prime spirals. Ulam Spiral is currently the only supported variation.
Read more about Ulam Spiral
explore spiral/src/main/java/spirals/ulam/examples for examples on how to generate spirals.
Example classes can be found under ./spiral/src/main/java/spirals/ulam/examples. Currently, divided into 2 categories: basic and density. Basic examples
simply calculate an Ulam's spiral and highlight or filter for a specific type of primes. Density examples calculate density of primes using different strategies.
Each example class can be customized, just modify the static variables above main method and run the method itself. Output will be saved
to an appropriate directory in ./output
- EB01_BasicUlam - generates simple Ulam's spiral of given size. Primes are black pixels, composites are white
- EB02_TwinPrimes - marks only twin primes or highlights them in red amongst all primes
- EB03_CousinPrimes - marks only cousin primes
- EB04_SexyPrimes - marks only sexy primes
- EB05_PrimeGap - marks neighbour primes with given gap distance
- ED01_RadiusBias - generates matrix of given size. Then each point is assigned a value equal to number of primes in a given radius. The brighter the pixel, the more primes are located around it. Actual primes can be applied a bias value - which is useful for highlighting them.
- ED02_DiagonalConnectionsWithinRadiusWithCutoff - similar to ED01 but only primes that are placed diagonally to given point are taken into consideration. Cutoff value can be set - points with density value below this threshold will not be marked (corresponding pixels will be same as background value)
- matrix compression (ability to store huge matrices in a small file)
- matrix caching - to speed up the generation process - pre-generated matrix to be read from file
- generating large matrices is taking too much time