add new functions and aliases to the old functions (#76)

* add new functions and aliases to the old functions

* add tests for new functions

3 files changed, 117 insertions, 7 deletions

diff --git a/README.md b/README.md
index f88e5e3..f589116 100644
--- a/README.md
+++ b/README.md
@@ -34,17 +34,22 @@ echo $executor->execute('1 + 2 * (2 - (4+10))^2 + sin(10)');
 ## Functions:
 Default functions:
 * abs
-* acos
+* acos (arccos)
 * acosh
-* asin
-* atan (atn)
+* arcctg (arccot, arccotan)
+* arcsec
+* arccsc (arccosec)
+* asin (arcsin)
+* atan (atn, arctan, arctg)
 * atan2
 * atanh
 * avg
 * bindec
 * ceil
 * cos
+* cosec (csc)
 * cosh
+* ctg (cot, cotan, cotg, ctn)
 * decbin
 * dechex
 * decoct
@@ -57,8 +62,8 @@ Default functions:
 * hypot
 * if
 * intdiv
-* log
-* log10
+* log (ln)
+* log10 (lg)
 * log1p
 * max
 * min
@@ -67,10 +72,11 @@ Default functions:
 * pow
 * rad2deg
 * round
+* sec
 * sin
 * sinh
 * sqrt
-* tan (tn)
+* tan (tn, tg)
 * tanh
 
 Add custom function to executor:
diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index b7abcad..1debc50 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -220,6 +220,36 @@ class MathExecutor
             'acosh' => function ($arg) {
                 return acosh($arg);
             },
+            'arcsin' => function ($arg) {
+                return asin($arg);
+            },
+            'arcctg' => function ($arg) {
+                return M_PI/2 - atan($arg);
+            },
+            'arccot' => function ($arg) {
+                return M_PI/2 - atan($arg);
+            },
+            'arccotan' => function ($arg) {
+                return M_PI/2 - atan($arg);
+            },
+            'arcsec' => function ($arg) {
+                return acos(1/$arg);
+            },
+            'arccosec' => function ($arg) {
+                return asin(1/$arg);
+            },
+            'arccsc' => function ($arg) {
+                return asin(1/$arg);
+            },
+            'arccos' => function ($arg) {
+                return acos($arg);
+            },
+            'arctan' => function ($arg) {
+                return atan($arg);
+            },
+            'arctg' => function ($arg) {
+                return atan($arg);
+            },
             'asin' => function ($arg) {
                 return asin($arg);
             },
@@ -247,9 +277,30 @@ class MathExecutor
             'cos' => function ($arg) {
                 return cos($arg);
             },
+            'cosec' => function ($arg) {
+                return 1 / sin($arg);
+            },
+            'csc' => function ($arg) {
+                return 1 / sin($arg);
+            },
             'cosh' => function ($arg) {
                 return cosh($arg);
             },
+            'ctg' => function ($arg) {
+                return cos($arg) / sin($arg);
+            },
+            'cot' => function ($arg) {
+                return cos($arg) / sin($arg);
+            },
+            'cotan' => function ($arg) {
+                return cos($arg) / sin($arg);
+            },
+            'cotg' => function ($arg) {
+                return cos($arg) / sin($arg);
+            },
+            'ctn' => function ($arg) {
+                return cos($arg) / sin($arg);
+            },
             'decbin' => function ($arg) {
                 return decbin($arg);
             },
@@ -295,6 +346,12 @@ class MathExecutor
             'intdiv' => function ($arg1, $arg2) {
                 return intdiv($arg1, $arg2);
             },
+            'ln' => function ($arg) {
+                return log($arg);
+            },
+            'lg' => function ($arg) {
+                return log10($arg);
+            },
             'log' => function ($arg) {
                 return log($arg);
             },
@@ -317,7 +374,7 @@ class MathExecutor
                 return pi();
             },
             'pow' => function ($arg1, $arg2) {
-                return pow($arg1, $arg2);
+                return $arg1 ** $arg2;
             },
             'rad2deg' => function ($arg) {
                 return rad2deg($arg);
@@ -331,6 +388,9 @@ class MathExecutor
             'sinh' => function ($arg) {
                 return sinh($arg);
             },
+            'sec' => function ($arg) {
+                return 1 / cos($arg);
+            },
             'sqrt' => function ($arg) {
                 return sqrt($arg);
             },
@@ -342,6 +402,9 @@ class MathExecutor
             },
             'tn' => function ($arg) {
                 return tan($arg);
+            },
+            'tg' => function ($arg) {
+                return tan($arg);
             }
         ];
     }
diff --git a/tests/MathTest.php b/tests/MathTest.php
index 4ea0cb0..65d8eac 100644
--- a/tests/MathTest.php
+++ b/tests/MathTest.php
@@ -526,4 +526,45 @@ class MathTest extends TestCase
         $this->expectException(MathExecutorException::class);
         $calculator->setVar('resource', tmpfile());
     }
+
+    /**
+     * @dataProvider providerExpressionValues
+     */
+    public function testCalculatingValues($expression, $value)
+    {
+        $calculator = new MathExecutor();
+
+        try {
+            $result = $calculator->execute($expression);
+        } catch (Exception $e) {
+            $this->fail(sprintf("Exception: %s (%s:%d), expression was: %s", get_class($e), $e->getFile(), $e->getLine(), $expression));
+        }
+        $this->assertEquals($value, $result, "${expression} did not evaluate to {$value}");
+    }
+
+    /**
+     * Expressions data provider
+     *
+     * Most tests can go in here.  The idea is that each expression will be evaluated by MathExecutor and by PHP with eval.
+     * The results should be the same.  If they are not, then the test fails.  No need to add extra test unless you are doing
+     * something more complex and not a simple mathmatical expression.
+     */
+    public function providerExpressionValues()
+    {
+        return [
+            ['arcsec(4)', 1.3181160716528],
+            ['arccsc(4)', 0.2526802551421],
+            ['arctan(4)', 1.3258176636680],
+            ['cosec(4)', -1.3213487088109],
+            ['cotan(4)', 0.8636911544506],
+            ['sec(4)', -1.5298856564664],
+            ['tg(4)', 1.1578212823496],
+            ['arcsin(0.5)', 0.5235987755983],
+            ['arccosec(4)', 0.2526802551421],
+            ['arccos(0.5)', 1.0471975511966],
+            ['arccotan(4)', 0.2449786631269],
+            ['ln(2)', 0.6931471805599],
+            ['lg(2)', 0.3010299956639],
+        ];
+    }
 }
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