add README and documentation for the main functions of tensor algebra

README.md

@@ -230,6 +230,18 @@ One can still use generic algebras though.
 > **Maturity**: EXPERIMENTAL
 <hr/>
 
+* ### [kmath-tensors](kmath-tensors)
+> 
+>
+> **Maturity**: PROTOTYPE
+>
+> **Features:**
+> - [tensor algebra](kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/api/TensorAlgebra.kt) : Basic linear algebra operations on tensors (plus, dot, etc.)
+> - [tensor algebra with broadcasting](kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/core/algebras/BroadcastDoubleTensorAlgebra.kt) : Basic linear algebra operations implemented with broadcasting.
+> - [linear algebra operations](kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/api/LinearOpsTensorAlgebra.kt) : Advanced linear algebra operations like LU decomposition, SVD, etc.
+
+<hr/>
+
 * ### [kmath-viktor](kmath-viktor)
 > 
 >

kmath-tensors/README.md

@@ -0,0 +1,37 @@
+# Module kmath-tensors
+
+Common linear algebra operations on tensors.
+
+ - [tensor algebra](src/commonMain/kotlin/space/kscience/kmath/tensors/api/TensorAlgebra.kt) : Basic linear algebra operations on tensors (plus, dot, etc.)
+ - [tensor algebra with broadcasting](src/commonMain/kotlin/space/kscience/kmath/tensors/core/algebras/BroadcastDoubleTensorAlgebra.kt) : Basic linear algebra operations implemented with broadcasting.
+ - [linear algebra operations](src/commonMain/kotlin/space/kscience/kmath/tensors/api/LinearOpsTensorAlgebra.kt) : Advanced linear algebra operations like LU decomposition, SVD, etc.
+
+
+## Artifact:
+
+The Maven coordinates of this project are `space.kscience:kmath-tensors:0.3.0-dev-7`.
+
+**Gradle:**
+```gradle
+repositories {
+    maven { url 'https://repo.kotlin.link' }
+    maven { url 'https://dl.bintray.com/hotkeytlt/maven' }
+    maven { url "https://dl.bintray.com/kotlin/kotlin-eap" } // include for builds based on kotlin-eap
+}
+
+dependencies {
+    implementation 'space.kscience:kmath-tensors:0.3.0-dev-7'
+}
+```
+**Gradle Kotlin DSL:**
+```kotlin
+repositories {
+    maven("https://repo.kotlin.link")
+    maven("https://dl.bintray.com/kotlin/kotlin-eap") // include for builds based on kotlin-eap
+    maven("https://dl.bintray.com/hotkeytlt/maven") // required for a
+}
+
+dependencies {
+    implementation("space.kscience:kmath-tensors:0.3.0-dev-7")
+}
+```

kmath-tensors/build.gradle.kts

@@ -11,6 +11,30 @@ kotlin.sourceSets {
     }
 }
 
+tasks.dokkaHtml {
+    dependsOn(tasks.build)
+}
+
 readme {
-    maturity = ru.mipt.npm.gradle.Maturity.EXPERIMENTAL
+    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+    propertyByTemplate("artifact", rootProject.file("docs/templates/ARTIFACT-TEMPLATE.md"))
+
+    feature(
+        id = "tensor algebra",
+        description = "Basic linear algebra operations on tensors (plus, dot, etc.)",
+        ref = "src/commonMain/kotlin/space/kscience/kmath/tensors/api/TensorAlgebra.kt"
+    )
+
+    feature(
+        id = "tensor algebra with broadcasting",
+        description = "Basic linear algebra operations implemented with broadcasting.",
+        ref = "src/commonMain/kotlin/space/kscience/kmath/tensors/core/algebras/BroadcastDoubleTensorAlgebra.kt"
+    )
+
+    feature(
+        id = "linear algebra operations",
+        description = "Advanced linear algebra operations like LU decomposition, SVD, etc.",
+        ref = "src/commonMain/kotlin/space/kscience/kmath/tensors/api/LinearOpsTensorAlgebra.kt"
+    )
+
 }

kmath-tensors/docs/README-TEMPLATE.md

@@ -0,0 +1,7 @@
+# Module kmath-tensors
+
+Common linear algebra operations on tensors.
+
+${features}
+
+${artifact}

kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/api/LinearOpsTensorAlgebra.kt

@@ -5,33 +5,99 @@
 
 package space.kscience.kmath.tensors.api
 
-
+/**
+ * Common linear algebra operations. Operates on [TensorStructure].
+ *
+ * @param T the type of items in the tensors.
+ */
 public interface LinearOpsTensorAlgebra<T> :
     TensorPartialDivisionAlgebra<T> {
 
-    //https://pytorch.org/docs/stable/linalg.html#torch.linalg.det
+    /**
+     * Computes the determinant of a square matrix input, or of each square matrix in a batched input.
+     * For more information: https://pytorch.org/docs/stable/linalg.html#torch.linalg.det
+     *
+     * @return the determinant.
+     */
     public fun TensorStructure<T>.det(): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/linalg.html#torch.linalg.inv
+    /**
+     * Computes the multiplicative inverse matrix of a square matrix input, or of each square matrix in a batched input.
+     * Given a square matrix `a`, return the matrix `aInv` satisfying
+     * ``a.dot(aInv) = aInv.dot(a) = eye(a.shape[0])``.
+     * For more information: https://pytorch.org/docs/stable/linalg.html#torch.linalg.inv
+     *
+     * @return the multiplicative inverse of a matrix.
+     */
     public fun TensorStructure<T>.inv(): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/linalg.html#torch.linalg.cholesky
+    /**
+     * Cholesky decomposition.
+     *
+     * Computes the Cholesky decomposition of a Hermitian (or symmetric for real-valued matrices)
+     * positive-definite matrix or the Cholesky decompositions for a batch of such matrices.
+     * Each decomposition has the form:
+     * Given a tensor `input`, return the tensor `L` satisfying ``input = L * L.H``,
+     * where L is a lower-triangular matrix and L.H is the conjugate transpose of L,
+     * which is just a transpose for the case of real-valued input matrices.
+     * For more information: https://pytorch.org/docs/stable/linalg.html#torch.linalg.cholesky
+     *
+     * @return the batch of L matrices.
+     */
     public fun TensorStructure<T>.cholesky(): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/linalg.html#torch.linalg.qr
+    /**
+     * QR decomposition.
+     *
+     * Computes the QR decomposition of a matrix or a batch of matrices, and returns a namedtuple `(Q, R)` of tensors.
+     * Given a tensor `input`, return tensors (Q, R) satisfying ``input = Q * R``,
+     * with `Q` being an orthogonal matrix or batch of orthogonal matrices
+     * and `R` being an upper triangular matrix or batch of upper triangular matrices.
+     * For more information: https://pytorch.org/docs/stable/linalg.html#torch.linalg.qr
+     *
+     * @return tuple of Q and R tensors.
+     */
     public fun TensorStructure<T>.qr(): Pair<TensorStructure<T>, TensorStructure<T>>
 
-    //https://pytorch.org/docs/stable/generated/torch.lu.html
+    /**
+     * TODO('Andrew')
+     * For more information: https://pytorch.org/docs/stable/generated/torch.lu.html
+     *
+     * @return ...
+     */
     public fun TensorStructure<T>.lu(): Pair<TensorStructure<T>, TensorStructure<Int>>
 
-    //https://pytorch.org/docs/stable/generated/torch.lu_unpack.html
+    /**
+     * TODO('Andrew')
+     * For more information: https://pytorch.org/docs/stable/generated/torch.lu_unpack.html
+     *
+     * @param luTensor ...
+     * @param pivotsTensor ...
+     * @return ...
+     */
     public fun luPivot(luTensor: TensorStructure<T>, pivotsTensor: TensorStructure<Int>):
             Triple<TensorStructure<T>, TensorStructure<T>, TensorStructure<T>>
 
-    //https://pytorch.org/docs/stable/linalg.html#torch.linalg.svd
+    /**
+     * Singular Value Decomposition.
+     *
+     * Computes the singular value decomposition of either a matrix or batch of matrices `input`.
+     * The singular value decomposition is represented as a namedtuple `(U, S, V)`,
+     * such that ``input = U.dot(diagonalEmbedding(S).dot(V.T))``.
+     * If input is a batch of tensors, then U, S, and Vh are also batched with the same batch dimensions as input.
+     * For more information: https://pytorch.org/docs/stable/linalg.html#torch.linalg.svd
+     *
+     * @return the determinant.
+     */
     public fun TensorStructure<T>.svd(): Triple<TensorStructure<T>, TensorStructure<T>, TensorStructure<T>>
 
-    //https://pytorch.org/docs/stable/generated/torch.symeig.html
+    /**
+     * Returns eigenvalues and eigenvectors of a real symmetric matrix input or a batch of real symmetric matrices,
+     * represented by a namedtuple (eigenvalues, eigenvectors).
+     * For more information: https://pytorch.org/docs/stable/generated/torch.symeig.html
+     *
+     * @return a namedtuple (eigenvalues, eigenvectors)
+     */
     public fun TensorStructure<T>.symEig(): Pair<TensorStructure<T>, TensorStructure<T>>
 
 }

kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/api/TensorAlgebra.kt

@@ -5,44 +5,243 @@
 
 package space.kscience.kmath.tensors.api
 
-// https://proofwiki.org/wiki/Definition:Algebra_over_Ring
+/**
+ * Basic linear algebra operations on [TensorStructure].
+ * For more information: https://proofwiki.org/wiki/Definition:Algebra_over_Ring
+ *
+ * @param T the type of items in the tensors.
+ */
 public interface TensorAlgebra<T> {
 
+    /**
+     * Returns a single tensor value of unit dimension. The tensor shape must be equal to [1].
+     *
+     * @return the value of a scalar tensor.
+     */
     public fun TensorStructure<T>.value(): T
 
+    /**
+     * Each element of the tensor [other] is added to this value.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be added.
+     * @return the sum of this value and tensor [other].
+     */
     public operator fun T.plus(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Adds the scalar [value] to each element of this tensor and returns a new resulting tensor.
+     *
+     * @param value the number to be added to each element of this tensor.
+     * @return the sum of this tensor and [value].
+     */
     public operator fun TensorStructure<T>.plus(value: T): TensorStructure<T>
+
+    /**
+     * Each element of the tensor [other] is added to each element of this tensor.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be added.
+     * @return the sum of this tensor and [other].
+     */
     public operator fun TensorStructure<T>.plus(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Adds the scalar [value] to each element of this tensor.
+     *
+     * @param value the number to be added to each element of this tensor.
+     */
     public operator fun TensorStructure<T>.plusAssign(value: T): Unit
+
+    /**
+     * Each element of the tensor [other] is added to each element of this tensor.
+     *
+     * @param other tensor to be added.
+     */
     public operator fun TensorStructure<T>.plusAssign(other: TensorStructure<T>): Unit
 
+
+    /**
+     * Each element of the tensor [other] is subtracted from this value.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be subtracted.
+     * @return the difference between this value and tensor [other].
+     */
     public operator fun T.minus(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Subtracts the scalar [value] from each element of this tensor and returns a new resulting tensor.
+     *
+     * @param value the number to be subtracted from each element of this tensor.
+     * @return the difference between this tensor and [value].
+     */
     public operator fun TensorStructure<T>.minus(value: T): TensorStructure<T>
+
+    /**
+     * Each element of the tensor [other] is subtracted from each element of this tensor.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be subtracted.
+     * @return the difference between this tensor and [other].
+     */
     public operator fun TensorStructure<T>.minus(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Subtracts the scalar [value] from each element of this tensor.
+     *
+     * @param value the number to be subtracted from each element of this tensor.
+     */
     public operator fun TensorStructure<T>.minusAssign(value: T): Unit
+
+    /**
+     * Each element of the tensor [other] is subtracted from each element of this tensor.
+     *
+     * @param other tensor to be subtracted.
+     */
     public operator fun TensorStructure<T>.minusAssign(other: TensorStructure<T>): Unit
 
+
+    /**
+     * Each element of the tensor [other] is multiplied by this value.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be multiplied.
+     * @return the product of this value and tensor [other].
+     */
     public operator fun T.times(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Multiplies the scalar [value] by each element of this tensor and returns a new resulting tensor.
+     *
+     * @param value the number to be multiplied by each element of this tensor.
+     * @return the product of this tensor and [value].
+     */
     public operator fun TensorStructure<T>.times(value: T): TensorStructure<T>
+
+    /**
+     * Each element of the tensor [other] is multiplied by each element of this tensor.
+     * The resulting tensor is returned.
+     *
+     * @param other tensor to be multiplied.
+     * @return the product of this tensor and [other].
+     */
     public operator fun TensorStructure<T>.times(other: TensorStructure<T>): TensorStructure<T>
+
+    /**
+     * Multiplies the scalar [value] by each element of this tensor.
+     *
+     * @param value the number to be multiplied by each element of this tensor.
+     */
     public operator fun TensorStructure<T>.timesAssign(value: T): Unit
+
+    /**
+     * Each element of the tensor [other] is multiplied by each element of this tensor.
+     *
+     * @param other tensor to be multiplied.
+     */
     public operator fun TensorStructure<T>.timesAssign(other: TensorStructure<T>): Unit
+
+    /**
+     * Numerical negative, element-wise.
+     *
+     * @return tensor - negation of the original tensor.
+     */
     public operator fun TensorStructure<T>.unaryMinus(): TensorStructure<T>
 
-    //https://pytorch.org/cppdocs/notes/tensor_indexing.html
+    /**
+     * Returns the tensor at index i
+     * For more information: https://pytorch.org/cppdocs/notes/tensor_indexing.html
+     *
+     * @param i index of the extractable tensor
+     * @return subtensor of the original tensor with index [i]
+     */
     public operator fun TensorStructure<T>.get(i: Int): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/generated/torch.transpose.html
+    /**
+     * Returns a tensor that is a transposed version of this tensor. The given dimensions [i] and [j] are swapped.
+     * For more information: https://pytorch.org/docs/stable/generated/torch.transpose.html
+     *
+     * @param i the first dimension to be transposed
+     * @param j the second dimension to be transposed
+     * @return transposed tensor
+     */
     public fun TensorStructure<T>.transpose(i: Int = -2, j: Int = -1): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/tensor_view.html
+    /**
+     * Returns a new tensor with the same data as the self tensor but of a different shape.
+     * The returned tensor shares the same data and must have the same number of elements, but may have a different size
+     * For more information: https://pytorch.org/docs/stable/tensor_view.html
+     *
+     * @param shape the desired size
+     * @return tensor with new shape
+     */
     public fun TensorStructure<T>.view(shape: IntArray): TensorStructure<T>
+
+    /**
+     * View this tensor as the same size as [other].
+     * ``this.viewAs(other) is equivalent to this.view(other.shape)``.
+     * For more information: https://pytorch.org/cppdocs/notes/tensor_indexing.html
+     *
+     * @param other the result tensor has the same size as other.
+     * @return the result tensor with the same size as other.
+     */
     public fun TensorStructure<T>.viewAs(other: TensorStructure<T>): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/generated/torch.matmul.html
+    /**
+     * Matrix product of two tensors.
+     *
+     * The behavior depends on the dimensionality of the tensors as follows:
+     * 1. If both tensors are 1-dimensional, the dot product (scalar) is returned.
+     *
+     * 2. If both arguments are 2-dimensional, the matrix-matrix product is returned.
+     *
+     * 3. If the first argument is 1-dimensional and the second argument is 2-dimensional,
+     * a 1 is prepended to its dimension for the purpose of the matrix multiply.
+     * After the matrix multiply, the prepended dimension is removed.
+     *
+     * 4. If the first argument is 2-dimensional and the second argument is 1-dimensional,
+     * the matrix-vector product is returned.
+     *
+     * 5. If both arguments are at least 1-dimensional and at least one argument is N-dimensional (where N > 2),
+     * then a batched matrix multiply is returned. If the first argument is 1-dimensional,
+     * a 1 is prepended to its dimension for the purpose of the batched matrix multiply and removed after.
+     * If the second argument is 1-dimensional, a 1 is appended to its dimension for the purpose of the batched matrix
+     * multiple and removed after.
+     * The non-matrix (i.e. batch) dimensions are broadcasted (and thus must be broadcastable).
+     * For example, if `input` is a (j \times 1 \times n \times n) tensor and `other` is a
+     * (k \times n \times n) tensor, out will be a (j \times k \times n \times n) tensor.
+     *
+     * For more information: https://pytorch.org/docs/stable/generated/torch.matmul.html
+     *
+     * @param other tensor to be multiplied
+     * @return mathematical product of two tensors
+     */
     public infix fun TensorStructure<T>.dot(other: TensorStructure<T>): TensorStructure<T>
 
-    //https://pytorch.org/docs/stable/generated/torch.diag_embed.html
+    /**
+     * Creates a tensor whose diagonals of certain 2D planes (specified by [dim1] and [dim2])
+     * are filled by [diagonalEntries].
+     * To facilitate creating batched diagonal matrices,
+     * the 2D planes formed by the last two dimensions of the returned tensor are chosen by default.
+     *
+     * The argument [offset]  controls which diagonal to consider:
+     * 1. If [offset] = 0, it is the main diagonal.
+     * 2. If [offset] > 0, it is above the main diagonal.
+     * 3. If [offset] < 0, it is below the main diagonal.
+     *
+     * The size of the new matrix will be calculated
+     * to make the specified diagonal of the size of the last input dimension.
+     * For more information: https://pytorch.org/docs/stable/generated/torch.diag_embed.html
+     *
+     * @param diagonalEntries - the input tensor. Must be at least 1-dimensional.
+     * @param offset - which diagonal to consider. Default: 0 (main diagonal).
+     * @param dim1 - first dimension with respect to which to take diagonal. Default: -2.
+     * @param dim2 - second dimension with respect to which to take diagonal. Default: -1.
+     *
+     * @return tensor whose diagonals of certain 2D planes (specified by [dim1] and [dim2])
+     * are filled by [diagonalEntries]
+     */
     public fun diagonalEmbedding(
         diagonalEntries: TensorStructure<T>,
         offset: Int = 0,

kmath-tensors/src/commonMain/kotlin/space/kscience/kmath/tensors/core/algebras/BroadcastDoubleTensorAlgebra.kt

@@ -10,6 +10,10 @@ import space.kscience.kmath.tensors.core.*
 import space.kscience.kmath.tensors.core.broadcastTensors
 import space.kscience.kmath.tensors.core.broadcastTo
 
+/**
+ * Basic linear algebra operations implemented with broadcasting.
+ * For more information: https://pytorch.org/docs/stable/notes/broadcasting.html
+ */
 public class BroadcastDoubleTensorAlgebra : DoubleTensorAlgebra() {
 
     override fun TensorStructure<Double>.plus(other: TensorStructure<Double>): DoubleTensor {