Merge pull request #729 from KaptenJon/Add-Extensions-To-Round-Numerics-Above-Zero

Add extension methods that allow round above zero
5 years ago · 710671a5e4
2 changed files with 242 additions and 0 deletions
--- a/src/Numerics.Tests/PrecisionTest.cs
+++ b/src/Numerics.Tests/PrecisionTest.cs
@ -28,6 +28,7 @@
 // </copyright>

 using System;
+using System.Numerics;
 using NUnit.Framework;

 namespace MathNet.Numerics.UnitTests
@ -1156,5 +1157,100 @@ namespace MathNet.Numerics.UnitTests
            Assert.AreEqual(-1, double.NegativeInfinity.CompareTo(1.0, Precision.DoubleDecimalPlaces));
            Assert.AreEqual(1, 1.0.CompareTo(double.NegativeInfinity, Precision.DoubleDecimalPlaces));
        }
+
+        [Test]
+        [TestCase(100.3123, 3, 0)]
+        [TestCase(1100.6123, 3, 1000)]
+        [TestCase(1500.8123, 3, 2000)]
+        [TestCase(110003245.3123, 3, 110003000)]
+        [TestCase(110003245.3123, 1, 110003250)]
+        [TestCase(110003245.3123, -2, 110003245.31)]
+        [TestCase(110003245.3123, 0, 110003245)]
+        public void RoundAboveDecimal(decimal number, int digit, decimal expectedResult)
+        {
+            Assert.AreEqual(expectedResult, number.RoundAboveZero(digit));
+        }
+
+        [Test]
+        [TestCase(100.3123, 3, 0)]
+        [TestCase(1100.6123, 3, 1000)]
+        [TestCase(1500.8123, 3, 2000)]
+        [TestCase(110003245.3123, 3, 110003000)]
+        [TestCase(110003245.3123, 1, 110003250)]
+        [TestCase(110003245.3123, -2, 110003245.31)]
+        [TestCase(110003245.3123, 0, 110003245)]
+        public void RoundAboveDouble(double number, int digit, double expectedResult)
+        {
+            Assert.AreEqual(expectedResult,number.RoundAboveZero(digit));
+        }
+
+        [Test]
+        [TestCase(100.3123f, 3, 0f)]
+        [TestCase(1100.6123f, 3, 1000f)]
+        [TestCase(1500.8123f, 3, 2000f)]
+        [TestCase(11245.3123f, 3, 11000f)]
+        [TestCase(13245.3123f, 1, 13250f)]
+        [TestCase(13245.3123f, -2, 13245.31f)]
+        [TestCase(13245.3123f, 0, 13245f)]
+        public void RoundAboveFloat(float number, int digit, float expectedResult)
+        {
+            Assert.AreEqual(expectedResult,number.RoundAboveZero(digit));
+        }
+
+        [Test]
+        [TestCase(100, 3, 0)]
+        [TestCase(1100, 3, 1000)]
+        [TestCase(1500, 3, 2000)]
+        [TestCase(110003245, 3, 110003000)]
+        [TestCase(110003245, 1, 110003250)]
+        [TestCase(110003245, -2, 110003245)]
+        public void RoundAboveInt(int number, int digit, int expectedResult)
+        {
+            Assert.AreEqual(expectedResult,number.RoundAboveZero(digit));
+        }
+
+        [Test]
+        public void RoundAboveUint()
+        {
+            Assert.AreEqual(110003250,((uint)110003245).RoundAboveZero(1));
+        }
+
+        
+        [Test]
+        public void RoundAboveUlong()
+        {
+            Assert.AreEqual(3250, ((ulong)3245).RoundAboveZero(1));
+        }
+
+        [Test]
+        [TestCase(110003245, 1, 110003250)]
+        public void RoundAboveLong(long number, int digit, int expectedResult)
+        {
+            Assert.AreEqual(expectedResult, number.RoundAboveZero(digit));
+        }
+
+        [Test]
+        public void RoundAboveShort()
+        {
+            Assert.AreEqual(3250, ((short)3245).RoundAboveZero(1));
+        }
+
+        [Test]
+        public void RoundAboveUshort()
+        {
+            Assert.AreEqual(3250,((ushort)3245).RoundAboveZero(1));
+        }
+
+        [Test]
+        public void RoundAboveBigInteger()
+        {
+            Assert.AreEqual(BigInteger.Zero,new BigInteger(100).RoundAboveZero(3));
+            Assert.AreEqual(new BigInteger(1000),new BigInteger(1100).RoundAboveZero(3));
+            Assert.AreEqual(new BigInteger(2000),new BigInteger(1500).RoundAboveZero(3));
+            Assert.AreEqual(new BigInteger(110003000), new BigInteger(110003245).RoundAboveZero(3));
+            Assert.AreEqual(new BigInteger(110003250), new BigInteger(110003245).RoundAboveZero(1));
+            Assert.AreEqual(new BigInteger(110003245), new BigInteger(110003245).RoundAboveZero(-2));
+            Assert.AreEqual(new BigInteger(110003245), new BigInteger(110003245).RoundAboveZero(0));
+        }
    }
 }
--- a/src/Numerics/Precision.cs
+++ b/src/Numerics/Precision.cs
@ -28,6 +28,7 @@
 // </copyright>

 using System;
+using System.Numerics;
 using System.Runtime;
 using System.Runtime.InteropServices;

@ -744,6 +745,151 @@ namespace MathNet.Numerics
            return eps;
        }

+        /// <summary>
+		/// Round to the number closest to 10^powerDigits. 
+		/// </summary>
+		/// <param name="number">Number to be rounded</param>
+		/// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+		/// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+		/// <returns>Rounded number</returns>
+		public static decimal RoundAboveZero(this decimal number, int powerDigits = 3)
+		{
+			if (powerDigits <= 0)
+				return Math.Round(number, powerDigits*-1,MidpointRounding.AwayFromZero);
+			return Math.Round(number / (decimal) Math.Pow(10, powerDigits),MidpointRounding.AwayFromZero) * (decimal) Math.Pow(10, powerDigits);
+		}
+
+		/// <summary>
+		/// Round to the number closest to 10^powerDigits. 
+		/// </summary>
+		/// <param name="number">Number to be rounded</param>
+		/// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+		/// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+		/// <returns>Rounded number</returns>
+		public static double RoundAboveZero(this double number, int powerDigits = 3)
+		{
+			if (powerDigits <= 0)
+				return Math.Round(number, powerDigits*-1,MidpointRounding.AwayFromZero);
+			return Math.Round(number / Math.Pow(10, powerDigits),MidpointRounding.AwayFromZero) * Math.Pow(10, powerDigits);
+		}
+
+		/// <summary>
+		/// Round to the number closest to 10^powerDigits. 
+		/// </summary>
+		/// <param name="number">Number to be rounded</param>
+		/// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+		/// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+		/// <returns>Rounded number</returns>
+		public static int RoundAboveZero(this int number, int powerDigits = 3)
+		{
+			if (powerDigits <= 0)
+				return number;
+            return (int) RoundAboveZero((decimal) number, powerDigits);
+		}
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static uint RoundAboveZero(this uint number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+            return (uint) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static ulong RoundAboveZero(this ulong number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+            return (ulong) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static long RoundAboveZero(this long number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+            return (long) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static short RoundAboveZero(this short number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+            return (short) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static ushort RoundAboveZero(this ushort number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+            return (ushort) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static float RoundAboveZero(this float number, int powerDigits = 3)
+        {
+            return (float) RoundAboveZero((decimal) number, powerDigits);
+        }
+
+        /// <summary>
+        /// Round to the number closest to 10^powerDigits. 
+        /// </summary>
+        /// <param name="number">Number to be rounded</param>
+        /// <param name="powerDigits">For closest 1000 enter 3, 10^powerDigits. If lower then zero you will get decimal digits.</param>
+        /// <example>To round 123456789 to hundreds RoundAboveZero(123456789, 2) = 123456800 </example>
+        /// <returns>Rounded number</returns>
+        public static BigInteger RoundAboveZero(this BigInteger number, int powerDigits = 3)
+        {
+            if (powerDigits <= 0)
+                return number;
+
+            var onelarger = number / BigInteger.Pow(10, powerDigits-1);
+            var divided = onelarger / 10;
+            var lastDigit = onelarger - divided * 10;
+            if (lastDigit >= 5)
+                divided += 1;
+            return divided * BigInteger.Pow(10, powerDigits);
+        }
+
        /// <summary>
        /// Calculates the actual positive double precision machine epsilon - the smallest number that can be added to 1, yielding a results different than 1.
        /// This is also known as unit roundoff error. According to the definition of Prof. Higham.