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Added internal mapping functionality to buffers.

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This commit is contained in:
Alexander Nozik 2019-01-16 15:18:26 +03:00
parent 7e83b080ad
commit 87e8566157
2 changed files with 139 additions and 53 deletions
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104
kmath-core/src/commonMain/kotlin/scientifik/kmath/linear/LUDecomposition.kt
View File

@ -188,57 +188,57 @@ class LUPDecompositionBuilder<T : Comparable<T>, F : Field<T>>(val context: F, v
}
//class LUSolver<T : Comparable<T>, F : Field<T>>(val singularityCheck: (T) -> Boolean) : LinearSolver<T, F> {
//
//
// override fun solve(a: Matrix<T>, b: Matrix<T>): Matrix<T> {
// val decomposition = LUPDecompositionBuilder(ring, singularityCheck).decompose(a)
//
// if (b.rowNum != a.colNum) {
// error("Matrix dimension mismatch expected ${a.rowNum}, but got ${b.colNum}")
// }
//
//
//// val bp = Array(a.rowNum) { Array<T>(b.colNum){ring.zero} }
//// for (row in 0 until a.rowNum) {
//// val bpRow = bp[row]
//// val pRow = decomposition.pivot[row]
//// for (col in 0 until b.colNum) {
//// bpRow[col] = b[pRow, col]
//// }
//// }
//
// // Apply permutations to b
// val bp = produce(a.rowNum, a.colNum) { i, j -> b[decomposition.pivot[i], j] }
//
// // Solve LY = b
// for (col in 0 until a.rowNum) {
// val bpCol = bp[col]
// for (i in col + 1 until a.rowNum) {
// val bpI = bp[i]
// val luICol = decomposition.lu[i, col]
// for (j in 0 until b.colNum) {
// bpI[j] -= bpCol[j] * luICol
// }
class LUSolver<T : Comparable<T>, F : Field<T>>(val singularityCheck: (T) -> Boolean) : LinearSolver<T, F> {
override fun solve(a: Matrix<T>, b: Matrix<T>): Matrix<T> {
val decomposition = LUPDecompositionBuilder(ring, singularityCheck).decompose(a)
if (b.rowNum != a.colNum) {
error("Matrix dimension mismatch expected ${a.rowNum}, but got ${b.colNum}")
}
// val bp = Array(a.rowNum) { Array<T>(b.colNum){ring.zero} }
// for (row in 0 until a.rowNum) {
// val bpRow = bp[row]
// val pRow = decomposition.pivot[row]
// for (col in 0 until b.colNum) {
// bpRow[col] = b[pRow, col]
// }
// }
//
// // Solve UX = Y
// for (col in a.rowNum - 1 downTo 0) {
// val bpCol = bp[col]
// val luDiag = decomposition.lu[col, col]
// for (j in 0 until b.colNum) {
// bpCol[j] /= luDiag
// }
// for (i in 0 until col) {
// val bpI = bp[i]
// val luICol = decomposition.lu[i, col]
// for (j in 0 until b.colNum) {
// bpI[j] -= bpCol[j] * luICol
// }
// }
// }
//
// return produce(a.rowNum, a.colNum) { i, j -> bp[i][j] }
// }
//}
// Apply permutations to b
val bp = produce(a.rowNum, a.colNum) { i, j -> b[decomposition.pivot[i], j] }
// Solve LY = b
for (col in 0 until a.rowNum) {
val bpCol = bp[col]
for (i in col + 1 until a.rowNum) {
val bpI = bp[i]
val luICol = decomposition.lu[i, col]
for (j in 0 until b.colNum) {
bpI[j] -= bpCol[j] * luICol
}
}
}
// Solve UX = Y
for (col in a.rowNum - 1 downTo 0) {
val bpCol = bp[col]
val luDiag = decomposition.lu[col, col]
for (j in 0 until b.colNum) {
bpCol[j] /= luDiag
}
for (i in 0 until col) {
val bpI = bp[i]
val luICol = decomposition.lu[i, col]
for (j in 0 until b.colNum) {
bpI[j] -= bpCol[j] * luICol
}
}
}
return produce(a.rowNum, a.colNum) { i, j -> bp[i][j] }
}
}

88
kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/Buffers.kt
View File

@ -10,15 +10,32 @@ typealias MutableBufferFactory<T> = (Int, (Int) -> T) -> MutableBuffer<T>
*/
interface Buffer<T> {
/**
* The size of the buffer
*/
val size: Int
/**
* Get element at given index
*/
operator fun get(index: Int): T
/**
* Iterate over all elements
*/
operator fun iterator(): Iterator<T>
/**
* Check content eqiality with another buffer
*/
fun contentEquals(other: Buffer<*>): Boolean =
asSequence().mapIndexed { index, value -> value == other[index] }.all { it }
/**
* Map the contents of the buffer to new buffer of the same type
*/
fun transform(transformation: (index: Int, value: T) -> T): Buffer<T>
companion object {
/**
@ -61,6 +78,8 @@ interface MutableBuffer<T> : Buffer<T> {
*/
fun copy(): MutableBuffer<T>
fun transformInPlace(transformation: (index: Int, value: T) -> T)
companion object {
/**
* Create a boxing mutable buffer of given type
@ -93,6 +112,9 @@ inline class ListBuffer<T>(private val list: List<T>) : Buffer<T> {
override fun get(index: Int): T = list[index]
override fun iterator(): Iterator<T> = list.iterator()
override fun transform(transformation: (index: Int, value: T) -> T): ListBuffer<T> =
list.mapIndexed(transformation).asBuffer()
}
fun <T> List<T>.asBuffer() = ListBuffer(this)
@ -110,11 +132,20 @@ inline class MutableListBuffer<T>(private val list: MutableList<T>) : MutableBuf
override fun iterator(): Iterator<T> = list.iterator()
override fun transform(transformation: (index: Int, value: T) -> T): ListBuffer<T> =
list.mapIndexed(transformation).asBuffer()
override fun copy(): MutableBuffer<T> = MutableListBuffer(ArrayList(list))
override fun transformInPlace(transformation: (index: Int, value: T) -> T) = list.forEachIndexed { index, value ->
list[index] = transformation(index, value)
}
}
fun <T> MutableList<T>.asBuffer() = MutableListBuffer(this)
class ArrayBuffer<T>(private val array: Array<T>) : MutableBuffer<T> {
//Can't inline because array invariant
//Can't inline because array is invariant
override val size: Int
get() = array.size
@ -127,8 +158,18 @@ class ArrayBuffer<T>(private val array: Array<T>) : MutableBuffer<T> {
override fun iterator(): Iterator<T> = array.iterator()
override fun copy(): MutableBuffer<T> = ArrayBuffer(array.copyOf())
override fun transform(transformation: (index: Int, value: T) -> T): ArrayBuffer<T> =
Array(size) { index -> transformation(index, get(index)) }.asBuffer()
override fun transformInPlace(transformation: (index: Int, value: T) -> T) = array.forEachIndexed { index, value ->
array[index] = transformation(index, value)
}
}
fun <T> Array<T>.asBuffer() = ArrayBuffer(this)
inline class DoubleBuffer(private val array: DoubleArray) : MutableBuffer<Double> {
override val size: Int get() = array.size
@ -141,8 +182,18 @@ inline class DoubleBuffer(private val array: DoubleArray) : MutableBuffer<Double
override fun iterator(): Iterator<Double> = array.iterator()
override fun copy(): MutableBuffer<Double> = DoubleBuffer(array.copyOf())
override fun transform(transformation: (index: Int, value: Double) -> Double): DoubleBuffer =
DoubleArray(size) { index -> transformation(index, get(index)) }.asBuffer()
override fun transformInPlace(transformation: (index: Int, value: Double) -> Double) =
array.forEachIndexed { index, value ->
array[index] = transformation(index, value)
}
}
fun DoubleArray.asBuffer() = DoubleBuffer(this)
inline class ShortBuffer(private val array: ShortArray) : MutableBuffer<Short> {
override val size: Int get() = array.size
@ -155,8 +206,18 @@ inline class ShortBuffer(private val array: ShortArray) : MutableBuffer<Short> {
override fun iterator(): Iterator<Short> = array.iterator()
override fun copy(): MutableBuffer<Short> = ShortBuffer(array.copyOf())
override fun transform(transformation: (index: Int, value: Short) -> Short): ShortBuffer =
ShortArray(size) { index -> transformation(index, get(index)) }.asBuffer()
override fun transformInPlace(transformation: (index: Int, value: Short) -> Short) =
array.forEachIndexed { index, value ->
array[index] = transformation(index, value)
}
}
fun ShortArray.asBuffer() = ShortBuffer(this)
inline class IntBuffer(private val array: IntArray) : MutableBuffer<Int> {
override val size: Int get() = array.size
@ -169,8 +230,18 @@ inline class IntBuffer(private val array: IntArray) : MutableBuffer<Int> {
override fun iterator(): Iterator<Int> = array.iterator()
override fun copy(): MutableBuffer<Int> = IntBuffer(array.copyOf())
override fun transform(transformation: (index: Int, value: Int) -> Int): IntBuffer =
IntArray(size) { index -> transformation(index, get(index)) }.asBuffer()
override fun transformInPlace(transformation: (index: Int, value: Int) -> Int) =
array.forEachIndexed { index, value ->
array[index] = transformation(index, value)
}
}
fun IntArray.asBuffer() = IntBuffer(this)
inline class LongBuffer(private val array: LongArray) : MutableBuffer<Long> {
override val size: Int get() = array.size
@ -183,14 +254,26 @@ inline class LongBuffer(private val array: LongArray) : MutableBuffer<Long> {
override fun iterator(): Iterator<Long> = array.iterator()
override fun copy(): MutableBuffer<Long> = LongBuffer(array.copyOf())
override fun transform(transformation: (index: Int, value: Long) -> Long): LongBuffer =
LongArray(size) { index -> transformation(index, get(index)) }.asBuffer()
override fun transformInPlace(transformation: (index: Int, value: Long) -> Long) =
array.forEachIndexed { index, value ->
array[index] = transformation(index, value)
}
}
fun LongArray.asBuffer() = LongBuffer(this)
inline class ReadOnlyBuffer<T>(private val buffer: MutableBuffer<T>) : Buffer<T> {
override val size: Int get() = buffer.size
override fun get(index: Int): T = buffer.get(index)
override fun iterator(): Iterator<T> = buffer.iterator()
override fun transform(transformation: (index: Int, value: T) -> T): Buffer<T> = buffer.transform(transformation)
}
/**
@ -210,6 +293,9 @@ class VirtualBuffer<T>(override val size: Int, private val generator: (Int) -> T
}
}
// TODO this composition could become very compex very fast, replace it by boxed generator?
override fun transform(transformation: (index: Int, value: T) -> T): Buffer<T> =
VirtualBuffer(size) { index -> transformation(index, generator(index)) }
}
/**