Documentation ¶
Overview ¶
Package pi calculates the nth and 8 following fractional decimal digits of pi using a Bailey-Borwein-Plouffe algorithm (see https://wikipedia.org/wiki/Bailey%E2%80%93Borwein%E2%80%93Plouffe_formula). This allows any arbitrary fractional digit of pi to be calculated independently of the preceding digits albeit with longer calculation times as the value of n increases because of the need to calculate prime numbers of increasing value.
NOTE 1: This package is intended to be used in distributed computing and cloud scaling demos, and does not guarantee accuracy or efficiency of calculated fractional digits.
NOTE 2: The algorithms used invMod, powMod, and BPPDigits are based on the work of Fabrice Bellard (original source code published at https://bellard.org/pi/pi.c).
Example ¶
package main import ( "fmt" "log" "os" "github.com/go-logr/stdr" pi "github.com/memes/pi/v2" ) func main() { // Enable verbose library logging to standard library logger via go-logr/stdr _ = stdr.SetVerbosity(1) pi.Logger = stdr.New(log.New(os.Stdout, "", log.Lshortfile)) // Calculate the first 9 decimal digits of pi digits := pi.BBPDigits(0) fmt.Printf("The first 10 digits of pi are: 3.%s\n", digits) }
Output: pi.go:109: "level"=1 "msg"="BBPDigits: enter" "n"=0 pi.go:171: "level"=1 "msg"="BBPDigits: exit" "n"=0 "result"="141592653" The first 10 digits of pi are: 3.141592653
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // The package logr.Logger instance to use. //nolint: gochecknoglobals // Allow package consumers to set the logger Logger = logr.Discard() // The number of Miller-Rabin rounds to use in FindNextPrime when // determining if an integer is probabilistically a prime. A value of // zero will apply a Baillie-PSW only test and requires Go 1.8+. //nolint: gochecknoglobals // Allow package consumers to override MillerRabinRounds = 0 )
Functions ¶
func BBPDigits ¶
Implements a BBP spigot algorithm to determine the nth and 8 following fractional decimal digits of pi at the specified zero-based offset.
Example ¶
package main import ( "fmt" pi "github.com/memes/pi/v2" ) func main() { // Print the first 100 digits of pi using a default calculator fmt.Printf("The first 100 digits of pi are: 3.") for n := uint64(0); n < 99; n += 9 { fmt.Print(pi.BBPDigits(n)) } fmt.Println() }
Output: The first 100 digits of pi are: 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067
func FindNextPrime ¶
Return the next largest prime number that is greater than n.
Example ¶
package main import ( "fmt" pi "github.com/memes/pi/v2" ) func main() { // Find the first prime number after 10,000 nextPrime := pi.FindNextPrime(10000) fmt.Printf("The first prime number greater than 10000 is %d\n", nextPrime) }
Output: The first prime number greater than 10000 is 10007
Types ¶
This section is empty.
Directories ¶
Path | Synopsis |
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cmd
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pi
This package contains a gRPC client and server to demonstrate use of library in a distributed environment.
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This package contains a gRPC client and server to demonstrate use of library in a distributed environment. |
pkg
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cache
Package cache defines a common interface for cache implementations that can be used by PiService implementations.
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Package cache defines a common interface for cache implementations that can be used by PiService implementations. |
client
Package client implements a gRPC client implementation that satisfies the PiServiceClient interface requirements with optional OpenTelemetry metrics and traces.
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Package client implements a gRPC client implementation that satisfies the PiServiceClient interface requirements with optional OpenTelemetry metrics and traces. |
generated
Package generated contains the generated code for gRPC client and server stubs, and an OpenAPIv2 (swagger) JSON declaration, from protobuf source(s).
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Package generated contains the generated code for gRPC client and server stubs, and an OpenAPIv2 (swagger) JSON declaration, from protobuf source(s). |
server
Package server implements a gRPC server (and optional REST gateway) implementation that satisfies the PiServiceClient interface requirements, with optional OpenTelemetry metrics and traces.
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Package server implements a gRPC server (and optional REST gateway) implementation that satisfies the PiServiceClient interface requirements, with optional OpenTelemetry metrics and traces. |