Goldmine
Extract a wealth of information from Arrays & Hashes.
Think of Goldmine as Enumerable#group_by
on steroids.
Uses
- Data mining
- Data transformation
- CSV report generation
- Prep for data visualization
- Fact table creation
The demo project demonstrates some of Goldmine's uses.
Quick Start
gem install goldmine
require "goldmine"
list = [1,2,3,4,5,6,7,8,9]
list = Goldmine::ArrayMiner.new(list)
list.pivot { |i| i < 5 }
# result:
{
true => [1, 2, 3, 4],
false => [5, 6, 7, 8, 9]
}
Chained Pivots
list = [1,2,3,4,5,6,7,8,9]
list = Goldmine::ArrayMiner.new(list)
list.pivot { |i| i < 5 }.pivot { |i| i % 2 == 0 }
# result:
{
[true, false] => [1, 3],
[true, true] => [2, 4],
[false, false] => [5, 7, 9],
[false, true] => [6, 8]
}
Named Pivots
list = [1,2,3,4,5,6,7,8,9]
list = Goldmine::ArrayMiner.new(list)
list.pivot(:less_than_5) { |i| i < 5 }
# result:
{
{ :less_than_5 => true } => [1, 2, 3, 4],
{ :less_than_5 => false } => [5, 6, 7, 8, 9]
}
Value Pivots
list = [
{ :name => "Sally", :favorite_colors => [:blue] },
{ :name => "John", :favorite_colors => [:blue, :green] },
{ :name => "Stephen", :favorite_colors => [:red, :pink, :purple] },
{ :name => "Emily", :favorite_colors => [:orange, :green] },
{ :name => "Joe", :favorite_colors => [:red] }
]
list = Goldmine::ArrayMiner.new(list)
list.pivot { |record| record[:favorite_colors] }
# result:
{
:blue => [
{ :name => "Sally", :favorite_colors => [:blue] },
{ :name => "John", :favorite_colors => [:blue, :green] }
],
:green => [
{ :name => "John", :favorite_colors => [:blue, :green] },
{ :name => "Emily", :favorite_colors => [:orange, :green] }
],
:red => [
{ :name => "Stephen", :favorite_colors => [:red, :pink, :purple] },
{ :name => "Joe", :favorite_colors => [:red] }
],
:pink => [
{ :name => "Stephen", :favorite_colors => [:red, :pink, :purple] }
],
:purple => [
{ :name => "Stephen", :favorite_colors => [:red, :pink, :purple] }
],
:orange => [
{ :name => "Emily", :favorite_colors => [:orange, :green] }
]
}
Stacked pivots
list = [
{ :name => "Sally", :age => 21 },
{ :name => "John", :age => 28 },
{ :name => "Stephen", :age => 37 },
{ :name => "Emily", :age => 32 },
{ :name => "Joe", :age => 18 }
]
list = Goldmine::ArrayMiner.new(list)
mined = list.pivot("Name has an 'e'") do |record|
!!record[:name].match(/e/i)
end
mined = mined.pivot(">= 21 years old") do |record|
record[:age] >= 21
end
# result:
{
{ "Name has an 'e'" => false, ">= 21 years old" => true } => [
{ :name => "Sally", :age => 21 },
{ :name => "John", :age => 28 }
],
{ "Name has an 'e'" => true, ">= 21 years old" => true } => [
{ :name => "Stephen", :age => 37 },
{ :name => "Emily", :age => 32 }
],
{ "Name has an 'e'" => true, ">= 21 years old" => false } => [
{ :name => "Joe", :age => 18 }
]
}