Permeability

shared/src/main/scala/squants/electro/Inductance.scala

@@ -22,7 +22,7 @@ final class Inductance private (val value: Double, val unit: InductanceUnit)
   def dimension = Inductance
 
   def *(that: ElectricCurrent): MagneticFlux = Webers(this.toHenry * that.toAmperes)
-  def /(that: Length) = ??? // returns Permeability
+  def /(that: Length): Permeability = HenriesPerMeter(this.toHenry / that.toMeters)
 
   def toHenry = to(Henry)
   def toMillihenry = to(Millihenry)

shared/src/main/scala/squants/electro/Permeability.scala

@@ -0,0 +1,66 @@
+/*                                                                      *\
+** Squants                                                              **
+**                                                                      **
+** Scala Quantities and Units of Measure Library and DSL                **
+** (c) 2015-2017, Carlos Quiroz                                         **
+**                                                                      **
+\*                                                                      */
+
+package squants.electro
+
+import squants._
+import squants.motion.Newtons
+
+/**
+ * Quantity and units for Permeability
+ *
+ * https://en.wikipedia.org/wiki/Permeability_(electromagnetism)
+ *
+ * @author  cquiroz
+ * @since   1.4
+ *
+ * @param value value in [[squants.electro.HenriesPerMeter]]
+ */
+final class Permeability private (val value: Double, val unit: PermeabilityUnit)
+    extends Quantity[Permeability] {
+
+  val dimension = Permeability
+
+  def *(that: Length): Inductance = Henry(this.toHenriesPerMeter * that.toMeters)
+
+  def toHenriesPerMeter = to(HenriesPerMeter)
+  def toNewtonsPerAmpereSquared = to(NewtonsPerAmperesSquared)
+}
+
+object Permeability extends Dimension[Permeability] {
+  private[electro] def apply[A](n: A, unit: PermeabilityUnit)(implicit num: Numeric[A]) = new Permeability(num.toDouble(n), unit)
+  val apply = parse _
+  val name = "Permeability"
+  val primaryUnit = HenriesPerMeter
+  val siUnit = HenriesPerMeter
+  val units = Set[UnitOfMeasure[Permeability]](HenriesPerMeter, NewtonsPerAmperesSquared)
+}
+
+trait PermeabilityUnit extends UnitOfMeasure[Permeability] with UnitConverter {
+  def apply[A](n: A)(implicit num: Numeric[A]) = Permeability(n, this)
+}
+
+object HenriesPerMeter extends PermeabilityUnit with PrimaryUnit with SiUnit {
+  val symbol = s"${Henry.symbol}/${Meters.symbol}"
+}
+
+object NewtonsPerAmperesSquared extends PermeabilityUnit with PrimaryUnit with SiUnit {
+  val symbol = s"${Newtons.symbol}/${Amperes.symbol}²"
+}
+
+object PermeabilityConversions {
+  lazy val henriesPerMeter = HenriesPerMeter(1)
+  lazy val newtonsPerAmperesSquared = NewtonsPerAmperesSquared(1)
+
+  implicit class PermeabilityConversions[A](n: A)(implicit num: Numeric[A]) {
+    def henriesPerMeter = HenriesPerMeter(n)
+    def newtonsPerAmperesSquared = NewtonsPerAmperesSquared(n)
+  }
+
+  implicit object PermeabilityNumeric extends AbstractQuantityNumeric[Permeability](Permeability.primaryUnit)
+}

shared/src/test/scala/squants/electro/InductanceSpec.scala

@@ -10,7 +10,7 @@ package squants.electro
 
 import org.scalatest.{FlatSpec, Matchers}
 import squants.{MetricSystem, QuantityParseException}
-
+import squants.space.Meters
 /**
  * @author  garyKeorkunian
  * @since   0.1
@@ -59,6 +59,10 @@ class InductanceSpec extends FlatSpec with Matchers {
     Henry(1) * Amperes(1) should be(Webers(1))
   }
 
+  it should "return Permeability when divided by Length" in {
+    Henry(1) / Meters(1) should be(HenriesPerMeter(1))
+  }
+
   behavior of "InductanceConversions"
 
   it should "provide aliases for single unit values" in {

shared/src/test/scala/squants/electro/PermeabilitySpec.scala

@@ -0,0 +1,77 @@
+/*                                                                      *\
+** Squants                                                              **
+**                                                                      **
+** Scala Quantities and Units of Measure Library and DSL                **
+** (c) 2015-2017, Carlos Quiroz                                         **
+**                                                                      **
+\*                                                                      */
+
+package squants.electro
+
+import org.scalatest.{FlatSpec, Matchers}
+import squants.{MetricSystem, QuantityParseException}
+import squants.space.Meters
+
+/**
+ * @author  cquiroz
+ * @since   1.4
+ *
+ */
+class PermeabilitySpec extends FlatSpec with Matchers {
+
+  behavior of "Permeability and its Units of Measure"
+
+  it should "create values using UOM factories" in {
+    HenriesPerMeter(1).toHenriesPerMeter should be(1)
+    NewtonsPerAmperesSquared(1).toNewtonsPerAmpereSquared should be(1)
+  }
+
+  it should "create values from properly formatted Strings" in {
+    Permeability("10.22 H/m").get should be(HenriesPerMeter(10.22))
+    Permeability("10.22 N/A²").get should be(HenriesPerMeter(10.22))
+    Permeability("10.22 zz").failed.get should be(QuantityParseException("Unable to parse Permeability", "10.22 zz"))
+    Permeability("zz H").failed.get should be(QuantityParseException("Unable to parse Permeability", "zz H"))
+  }
+
+  it should "properly convert to all supported Units of Measure" in {
+    val x = HenriesPerMeter(1)
+    x.toHenriesPerMeter should be(1.0)
+    x.toNewtonsPerAmpereSquared should be(1.0)
+    val y = NewtonsPerAmperesSquared(1)
+    y.toHenriesPerMeter should be(1.0)
+    y.toNewtonsPerAmpereSquared should be(1.0)
+  }
+
+  it should "return properly formatted strings for all supported Units of Measure" in {
+    HenriesPerMeter(1).toString(HenriesPerMeter) should be("1.0 H/m")
+    NewtonsPerAmperesSquared(1).toString(NewtonsPerAmperesSquared) should be("1.0 N/A²")
+  }
+
+  it should "return Inductance when multiplied by Distance" in {
+    HenriesPerMeter(1) * Meters(1) should be(Henry(1))
+  }
+
+  behavior of "PermeabilityConversions"
+
+  it should "provide aliases for single unit values" in {
+    import PermeabilityConversions._
+
+    henriesPerMeter should be(HenriesPerMeter(1))
+    newtonsPerAmperesSquared should be(NewtonsPerAmperesSquared(1))
+  }
+
+  it should "provide implicit conversion from Double" in {
+    import PermeabilityConversions._
+
+    val d = 10d
+    d.henriesPerMeter should be(HenriesPerMeter(d))
+    d.newtonsPerAmperesSquared should be(NewtonsPerAmperesSquared(d))
+  }
+
+  it should "provide Numeric support" in {
+    import PermeabilityConversions.PermeabilityNumeric
+
+    val is = List(HenriesPerMeter(100), HenriesPerMeter(10))
+    is.sum should be(HenriesPerMeter(110))
+  }
+}