Kotlin: added heliocentric/topocentric state vector tests.

generate/template/astronomy.kt

@@ -921,6 +921,20 @@ data class StateVector(
             verifyIdenticalTimes(t, other.t)
         )
 
+    /**
+     * Subtracts two state vetors, yielding the state vector difference.
+     */
+    operator fun minus(other: StateVector) =
+        StateVector(
+            x - other.x,
+            y - other.y,
+            z - other.z,
+            vx - other.vx,
+            vy - other.vy,
+            vz - other.vz,
+            verifyIdenticalTimes(t, other.t)
+        )
+
     /**
      * Divides a state vector by a scalar.
      */
@@ -934,6 +948,12 @@ data class StateVector(
             vz / denom,
             t
         )
+
+    /**
+     * Negates a state vector; the same as multiplying the state vector by the scalar -1.
+     */
+    operator fun unaryMinus() =
+        StateVector(-x, -y, -z, -vx, -vy, -vz, t)
 }
 
 

source/kotlin/doc/-state-vector/index.md

@@ -19,8 +19,10 @@ Represents a combined position vector and velocity vector at a given moment in t
 | Name | Summary |
 |---|---|
 | [div](div.md) | [jvm]<br>operator fun [div](div.md)(denom: [Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)): [StateVector](index.md)<br>Divides a state vector by a scalar. |
+| [minus](minus.md) | [jvm]<br>operator fun [minus](minus.md)(other: [StateVector](index.md)): [StateVector](index.md)<br>Subtracts two state vetors, yielding the state vector difference. |
 | [plus](plus.md) | [jvm]<br>operator fun [plus](plus.md)(other: [StateVector](index.md)): [StateVector](index.md)<br>Adds two state vetors, yielding the state vector sum. |
 | [position](position.md) | [jvm]<br>fun [position](position.md)(): [Vector](../-vector/index.md)<br>Returns the position vector associated with this state vector. |
+| [unaryMinus](unary-minus.md) | [jvm]<br>operator fun [unaryMinus](unary-minus.md)(): [StateVector](index.md)<br>Negates a state vector; the same as multiplying the state vector by the scalar -1. |
 | [velocity](velocity.md) | [jvm]<br>fun [velocity](velocity.md)(): [Vector](../-vector/index.md)<br>Returns the velocity vector associated with this state vector. |
 
 ## Properties

source/kotlin/doc/-state-vector/minus.md

@@ -0,0 +1,8 @@
+//[astronomy](../../../index.md)/[io.github.cosinekitty.astronomy](../index.md)/[StateVector](index.md)/[minus](minus.md)
+
+# minus
+
+[jvm]\
+operator fun [minus](minus.md)(other: [StateVector](index.md)): [StateVector](index.md)
+
+Subtracts two state vetors, yielding the state vector difference.

source/kotlin/doc/-state-vector/unary-minus.md

@@ -0,0 +1,8 @@
+//[astronomy](../../../index.md)/[io.github.cosinekitty.astronomy](../index.md)/[StateVector](index.md)/[unaryMinus](unary-minus.md)
+
+# unaryMinus
+
+[jvm]\
+operator fun [unaryMinus](unary-minus.md)(): [StateVector](index.md)
+
+Negates a state vector; the same as multiplying the state vector by the scalar -1.

source/kotlin/src/main/kotlin/io/github/cosinekitty/astronomy/astronomy.kt

@@ -921,6 +921,20 @@ data class StateVector(
             verifyIdenticalTimes(t, other.t)
         )
 
+    /**
+     * Subtracts two state vetors, yielding the state vector difference.
+     */
+    operator fun minus(other: StateVector) =
+        StateVector(
+            x - other.x,
+            y - other.y,
+            z - other.z,
+            vx - other.vx,
+            vy - other.vy,
+            vz - other.vz,
+            verifyIdenticalTimes(t, other.t)
+        )
+
     /**
      * Divides a state vector by a scalar.
      */
@@ -934,6 +948,12 @@ data class StateVector(
             vz / denom,
             t
         )
+
+    /**
+     * Negates a state vector; the same as multiplying the state vector by the scalar -1.
+     */
+    operator fun unaryMinus() =
+        StateVector(-x, -y, -z, -vx, -vy, -vz, t)
 }
 
 

source/kotlin/src/test/kotlin/io/github/cosinekitty/astronomy/Tests.kt

@@ -389,7 +389,8 @@ class Tests {
 
         // I used the Python version to calculate reference state vectors.
         // This is just a sanity check.
-        // More exhaustive tests will be added later.
+        // Exhaustive tests referenced against JPL Horizons data
+        // are done separately by the test `Heliocentric state vectors`.
 
         verifyHelio(
             Body.Mercury,
@@ -1547,5 +1548,34 @@ class Tests {
         verifyStateBody("barystate/GeoEMB.txt",   4.076e-05,  5.335e-05) { time -> geoEmbState(time)  }
     }
 
+    @Test
+    fun `Heliocentric state vectors`() {
+        verifyStateBody("heliostate/SSB.txt",     -1.209e-05, -1.125e-07) { time -> helioState(Body.SSB,     time) }
+        verifyStateBody("heliostate/Mercury.txt",  1.481e-04,  2.756e-04) { time -> helioState(Body.Mercury, time) }
+        verifyStateBody("heliostate/Venus.txt",    3.528e-05,  4.485e-05) { time -> helioState(Body.Venus,   time) }
+        verifyStateBody("heliostate/Earth.txt",    1.476e-05,  6.105e-05) { time -> helioState(Body.Earth,   time) }
+        verifyStateBody("heliostate/Mars.txt",     3.154e-05,  5.603e-05) { time -> helioState(Body.Mars,    time) }
+        verifyStateBody("heliostate/Jupiter.txt",  7.455e-05,  2.562e-04) { time -> helioState(Body.Jupiter, time) }
+        verifyStateBody("heliostate/Saturn.txt",   1.066e-04,  3.150e-04) { time -> helioState(Body.Saturn,  time) }
+        verifyStateBody("heliostate/Uranus.txt",   9.034e-05,  2.712e-04) { time -> helioState(Body.Uranus,  time) }
+        verifyStateBody("heliostate/Neptune.txt",  9.834e-05,  4.534e-04) { time -> helioState(Body.Neptune, time) }
+        verifyStateBody("heliostate/Pluto.txt",    4.271e-05,  1.198e-04) { time -> helioState(Body.Pluto,   time) }
+        verifyStateBody("heliostate/Moon.txt",     1.477e-05,  6.195e-05) { time -> helioState(Body.Moon,    time) }
+        verifyStateBody("heliostate/EMB.txt",      1.476e-05,  6.106e-05) { time -> helioState(Body.EMB,     time) }
+    }
+
+    @Test
+    fun `Topocentric state vectors`() {
+        val observer = Observer(30.0, -80.0, 1000.0)
+
+        verifyStateBody("topostate/Earth_N30_W80_1000m.txt", 2.108e-04, 2.430e-04) {
+            time -> -observer.toStateVector(time, EquatorEpoch.J2000)
+        }
+
+        verifyStateBody("topostate/EMB_N30_W80_1000m.txt", 7.195e-04, 2.497e-04) {
+            time -> geoEmbState(time) - observer.toStateVector(time, EquatorEpoch.J2000)
+        }
+    }
+
     //----------------------------------------------------------------------------------------
 }