Add inverse methods for electric conductivity and resistivity (#943)

Author: tmilnthorp

UnitsNet.Tests/CustomCode/ElectricConductivityTests.cs

@@ -22,6 +22,8 @@
 
 
 using System;
+using UnitsNet.Units;
+using Xunit;
 
 namespace UnitsNet.Tests.CustomCode
 {
@@ -31,5 +33,19 @@ public class ElectricConductivityTests : ElectricConductivityTestsBase
         protected override double SiemensPerMeterInOneSiemensPerMeter => 1;
         protected override double SiemensPerInchInOneSiemensPerMeter => 2.54e-2;
         protected override double SiemensPerFootInOneSiemensPerMeter => 3.048e-1;
+
+        [Theory]
+        [InlineData( -1.0, -1.0 )]
+        [InlineData( -2.0, -0.5 )]
+        [InlineData( 0.0, 0.0 )]
+        [InlineData( 1.0, 1.0 )]
+        [InlineData( 2.0, 0.5 )]
+        public static void InverseTest( double value, double expected )
+        {
+            var unit = new ElectricConductivity( value, ElectricConductivityUnit.SiemensPerMeter );
+            var inverse = unit.Inverse();
+
+            AssertEx.Equals( expected, inverse.OhmMeters );
+        }
     }
 }

UnitsNet.Tests/CustomCode/ElectricResistivityTests.cs

@@ -22,6 +22,8 @@
 
 
 using System;
+using UnitsNet.Units;
+using Xunit;
 
 namespace UnitsNet.Tests.CustomCode
 {
@@ -55,5 +57,19 @@ public class ElectricResistivityTests : ElectricResistivityTestsBase
         protected override double PicoohmsCentimeterInOneOhmMeter => 1e14;
 
         protected override double PicoohmMetersInOneOhmMeter => 1e+12;
+
+        [Theory]
+        [InlineData( -1.0, -1.0 )]
+        [InlineData( -2.0, -0.5 )]
+        [InlineData( 0.0, 0.0 )]
+        [InlineData( 1.0, 1.0 )]
+        [InlineData( 2.0, 0.5 )]
+        public static void InverseTest( double value, double expected )
+        {
+            var unit = new ElectricResistivity( value, ElectricResistivityUnit.OhmMeter );
+            var inverse = unit.Inverse();
+
+            AssertEx.Equals( expected, inverse.SiemensPerMeter );
+        }
     }
 }

UnitsNet/CustomCode/Quantities/ElectricConductivity.extra.cs

@@ -0,0 +1,22 @@
+// Licensed under MIT No Attribution, see LICENSE file at the root.
+// Copyright 2013 Andreas Gullberg Larsen ([email protected]). Maintained at https://github.com/angularsen/UnitsNet.
+
+using UnitsNet.Units;
+
+namespace UnitsNet
+{
+    public partial struct ElectricConductivity
+    {
+        /// <summary>
+        /// Calculates the inverse or <see cref="ElectricResistivity"/> of this unit.
+        /// </summary>
+        /// <returns>The inverse or <see cref="ElectricResistivity"/> of this unit.</returns>
+        public ElectricResistivity Inverse()
+        {
+            if( SiemensPerMeter == 0.0 )
+                return new ElectricResistivity( 0.0, ElectricResistivityUnit.OhmMeter );
+
+            return new ElectricResistivity( 1 / SiemensPerMeter, ElectricResistivityUnit.OhmMeter );
+        }
+    }
+}

UnitsNet/CustomCode/Quantities/ElectricResistivity.extra.cs

@@ -0,0 +1,22 @@
+// Licensed under MIT No Attribution, see LICENSE file at the root.
+// Copyright 2013 Andreas Gullberg Larsen ([email protected]). Maintained at https://github.com/angularsen/UnitsNet.
+
+using UnitsNet.Units;
+
+namespace UnitsNet
+{
+    public partial struct ElectricResistivity
+    {
+        /// <summary>
+        /// Calculates the inverse or <see cref="ElectricConductivity"/> of this unit.
+        /// </summary>
+        /// <returns>The inverse or <see cref="ElectricConductivity"/> of this unit.</returns>
+        public ElectricConductivity Inverse()
+        {
+            if( OhmMeters == 0.0 )
+                return new ElectricConductivity( 0, ElectricConductivityUnit.SiemensPerMeter );
+
+            return new ElectricConductivity( 1 / OhmMeters, ElectricConductivityUnit.SiemensPerMeter );
+        }
+    }
+}