Updated contexts

Author: JordanRL

.gitignore

@@ -1,2 +1,3 @@
 .idea
-vendor/
+vendor/
+composer.lock

composer.json

@@ -1,6 +1,7 @@
 {
   "name": "samsara/cantor",
   "require": {
+    "ircmaxell/random-lib": "1.1.*",
     "ext-stats": "*"
   },
   "require-dev": {

src/Samsara/Cantor/Context/Base/BaseContext.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Samsara\Cantor\Context\Base;
+
+use Samsara\Cantor\Values\Base\NumberInterface;
+
+abstract class BaseContext
+{
+
+    protected $contextBase;
+
+    /**
+     * @var string|NumberInterface
+     */
+    protected $numberType;
+
+    public function setBase($base)
+    {
+        $this->contextBase = $base;
+
+        return $this;
+    }
+
+    public function changeBase($base)
+    {
+        return $this->transformBaseContext($base)->setBase($base);
+    }
+
+    /**
+     * Must be implemented by each context. This method transforms the base of ALL NumberInterface objects which are
+     * stored as class properties within the context so that the actual math is preserved no matter what base it's in.
+     *
+     * @param   int $base
+     * @return      $this
+     */
+    abstract protected function transformBaseContext($base);
+
+}

src/Samsara/Cantor/Bounds/GaussianBound.php src/Samsara/Cantor/Context/GaussianContext.php

@@ -1,13 +1,16 @@
 <?php
 
-namespace Samsara\Cantor\Bounds;
+namespace Samsara\Cantor\Context;
 
 use Samsara\Cantor\Numbers;
 use Samsara\Cantor\Provider\BCProvider;
 use Samsara\Cantor\Provider\GaussianProvider;
 use Samsara\Cantor\Values\Base\NumberInterface;
 
-class GaussianBound
+/**
+ * Used for operating on numbers within the context of a Gaussian (or normal) distribution.
+ */
+class GaussianContext
 {
 
     /**
@@ -20,8 +23,6 @@ class GaussianBound
      */
     protected $standardDev;
 
-    protected $numberType;
-
     /**
      * @var NumberInterface
      */
@@ -123,9 +124,9 @@ public function PDFByValue($value)
 
     public function random()
     {
-        $rand = GaussianProvider::random($this->getMean(), $this->getSD());
+        $rand = GaussianProvider::random($this->getMean()->getValue(), $this->getSD()->getValue());
 
-        return $rand;
+        return Numbers::make($this->numberType, $rand);
     }
 
 }

src/Samsara/Cantor/Bounds/LinearBound.php src/Samsara/Cantor/Context/OpenContext.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Samsara\Cantor\Context;
+
+use RandomLib\Factory;
+use RandomLib\Source\Random;
+use Samsara\Cantor\Context\Base\BaseContext;
+use Samsara\Cantor\Numbers;
+use Samsara\Cantor\Provider\BCProvider;
+use Samsara\Cantor\Values\Base\NumberInterface;
+
+/**
+ * Used for operating on numbers withing a polynomial context.
+ */
+class PolynomialContext extends BaseContext
+{
+
+    /**
+     * The exponents and coefficients present in this polynomial. This is ALWAYS represented in base10 regardless of
+     * the context base, in order to take advantage of the fact that PHP and most computer programming languages are
+     * base10 by default.
+     *
+     * The format for this array is:
+     *
+     * $equationDefinition[$exponent] => $coefficient
+     *
+     * Meaning that this equation:
+     *
+     * 2x^4 + x^2 - 7x + 3
+     *
+     * Would be represented by:
+     *
+     * [
+     *  0 => 3,
+     *  1 => -7,
+     *  2 => 1,
+     *  3 => 0, // This could also be omitted
+     *  4 => 2
+     * ]
+     *
+     * @var array                   $definition
+     * @var string|NumberInterface  $type
+     */
+    protected $equationDefinition = [];
+
+    public function __construct(array $definition, $type)
+    {
+        $this->numberType = $type;
+
+        $this->equationDefinition = $definition;
+    }
+
+    public function random()
+    {
+        $randFactory = new Factory();
+        $x = $randFactory->getMediumStrengthGenerator()->generateInt();
+
+        return $this->getY($x);
+    }
+
+    public function getY($x)
+    {
+        $value = 0;
+
+        foreach ($this->equationDefinition as $exponent => $coefficient) {
+            $value = BCProvider::add(
+                $value,
+                BCProvider::multiply(
+                    $coefficient,
+                    BCProvider::exp(
+                        $x,
+                        $exponent
+                    )
+                )
+            );
+        }
+
+        return Numbers::make(
+            $this->numberType,
+            $value
+        );
+    }
+
+    protected function transformBaseContext($base)
+    {
+        return $this;
+    }
+
+}