Added:

 - random matrix method without to replace the version with default random.
 - Matrix.rowVector
 - Matrix.columnVector
 - Tests for transpose, rowVector, and columnVector

Fixed bug in rowVectors that only showed up in JavaScript environments.

slash/shared/src/main/scala/slash/matrix/Matrix.scala

@@ -16,8 +16,8 @@
 
 package slash.matrix
 
-import slash.vector.*
 import narr.*
+import slash.vector.*
 
 import scala.compiletime.ops.int.*
 import scala.math.hypot
@@ -34,14 +34,16 @@ object Matrix {
    */
   inline def copyFrom[M <: Int, N <: Int](values: NArray[Double])(using ValueOf[M], ValueOf[N]): Matrix[M, N] = apply(narr.copy[Double](values))
 
+  inline def random[M <: Int, N <: Int](using ValueOf[M], ValueOf[N]): Matrix[M, N] = random[M, N](slash.Random.defaultRandom)
+
   /**
    * Generates an MxN matrix which consists of elements randomized between [-1.0, 1.0] inclusive.
    * @param r optional random instance.
    * @tparam M the number of rows
    * @tparam N the number of columns
    * @return An MxN matrix with uniformly distributed random elements.
    */
-  inline def random[M <: Int, N <: Int](r:scala.util.Random = slash.Random.defaultRandom)(using ValueOf[M], ValueOf[N]):Matrix[M, N] = {
+  inline def random[M <: Int, N <: Int](r:scala.util.Random)(using ValueOf[M], ValueOf[N]):Matrix[M, N] = {
     random(slash.interval.`[]`(-1.0, 1.0), r)
   }
 
@@ -252,13 +254,30 @@ class Matrix[M <: Int, N <: Int] (val values: NArray[Double])(using ValueOf[M],
     */
   inline def rowPackedArray: NArray[Double] = copyValues
 
-  def columnVectors: NArray[Vec[M]] = NArray.tabulate[Vec[M]](columns)(
-    (i: Int) => columnPackedArray.slice(i * rows, columns).asInstanceOf[Vec[M]]
+  /**
+   * @param row the row of the matrix to return as a vector.
+   * @return a copy of the specified matrix row in Vec[N] format.
+   */
+  inline def rowVector(row:Int):Vec[N] = Vec.apply[N](
+    values.asInstanceOf[NArr[Double]].slice(row * columns, (row * columns) + columns).asInstanceOf[NArray[Double]]
   )
 
-  def rowVectors: NArray[Vec[N]] = NArray.tabulate[Vec[N]](rows)(
-    (i: Int) => values.slice(i * columns, (i * columns) + columns).asInstanceOf[Vec[N]]
-  )
+  /**
+   * @return a copy of this matrix in the form of an array of row vectors.
+   */
+  def rowVectors: NArray[Vec[N]] = NArray.tabulate[Vec[N]](rows)( (row: Int) => rowVector(row) )
+
+  /**
+   * @param column the column of the matrix to return as a vector.
+   * @return a copy of the specified matrix column in Vec[M] format.
+   */
+  inline def columnVector(column:Int):Vec[M] = Vec.tabulate[M]( (r:Int) => apply(r, column) )
+
+  /**
+   * @return a copy of this matrix in the form of an array of column vectors.
+   */
+  def columnVectors: NArray[Vec[M]] = transpose.rowVectors
+
 
   /** Get row dimension.
     *

tests/shared/src/test/scala/MatrixExtensionsTest.scala

@@ -19,13 +19,13 @@ import slash.matrix.*
 
 class MatrixExtensionsTest extends munit.FunSuite {
   test("Matrix[1, N] -> Vec[N] -> Matrix[1, N]") {
-    val m1x1:Matrix[1,1] = Matrix.random[1,1]()
+    val m1x1:Matrix[1,1] = Matrix.random[1,1]
     val m1x1Vec:Vec[1] = m1x1.asVector
     assertMatrixEquals[1, 1]( m1x1, m1x1Vec.asRowMatrix )
     assertMatrixEquals[1, 1]( m1x1, m1x1Vec.asColumnMatrix )
 
     type N = 42
-    val m: Matrix[1, N] = Matrix.random[1, N]()
+    val m: Matrix[1, N] = Matrix.random[1, N]
     val mVec: Vec[N] = m.asVector
     assertMatrixEquals[1, N](m, mVec.asRowMatrix)
 

tests/shared/src/test/scala/MatrixTest.scala

@@ -14,8 +14,32 @@
  * limitations under the License.
  */
 
+import narr.*
+import slash.vector.*
+import slash.matrix.*
+
 class MatrixTest extends munit.FunSuite {
 
-
+  val m:Matrix[11, 7] = Matrix.random[11, 7]
+  val mT: Matrix[7, 11] = m.transpose
+
+  test( " m == m.transpose.transpose " ) {
+    assertMatrixEquals(m, mT.transpose)
+  }
+
+  test(" compare m.rowVector to m.transpose.columnVector ") {
+
+    // compare m's row vectors to mT's column vectors:
+    var i: Int = 0;
+    while (i < m.rowDimension ) {
+      assertVecEquals(m.rowVector(i), mT.columnVector(i))
+      i += 1
+    }
 
+    var j: Int = 0;
+    while (j < m.columns) {
+      assertVecEquals(m.columnVector(j), mT.rowVector(j))
+      j += 1
+    }
+  }
 }

verification/src/main/scala/verification/matrix/MatrixMethods.scala

@@ -48,7 +48,7 @@ object MatrixMethods extends Verification {
       )
     }")
 
-    val m4x4: Matrix[4, 4] = Matrix.random[4, 4]()
+    val m4x4: Matrix[4, 4] = Matrix.random[4, 4]
     // def setMatrix[M1 <: Int, N1 <: Int](rowIndices: NArray[Int], c0: Int, thatMatrix: Matrix[M1, N1])
     println(s"\t- setMatrix([], 3, ${m4x4.dim}) : ${
       val jm4x4: Jama.Matrix = new Jama.Matrix(m4x4.rowVectors.asInstanceOf[Array[Array[Double]]])