From 99ee5aa54a043427d8ade94c82107cdc18e48819 Mon Sep 17 00:00:00 2001 From: AlyaNovikova Date: Tue, 16 Mar 2021 14:57:19 +0300 Subject: [PATCH] add broadcast to functions --- .../kmath/tensors/DoubleTensorAlgebra.kt | 30 ++++++++------- .../space/kscience/kmath/tensors/utils.kt | 37 +++++++++++++++++++ .../kmath/tensors/TestDoubleTensorAlgebra.kt | 10 +++++ 3 files changed, 64 insertions(+), 13 deletions(-) diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/DoubleTensorAlgebra.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/DoubleTensorAlgebra.kt index c383387ef..794a06102 100644 --- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/DoubleTensorAlgebra.kt +++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/DoubleTensorAlgebra.kt @@ -69,10 +69,10 @@ public open class DoubleTensorAlgebra : TensorPartialDivisionAlgebra other.buffer.array()[other.bufferStart + i] * this } return DoubleTensor(other.shape, resBuffer) } - //todo should be change with broadcasting override fun DoubleTensor.times(value: Double): DoubleTensor = value * this override fun DoubleTensor.times(other: DoubleTensor): DoubleTensor { - //todo should be change with broadcasting - val resBuffer = DoubleArray(this.strides.linearSize) { i -> - this.buffer.array()[other.bufferStart + i] * - other.buffer.array()[other.bufferStart + i] + val broadcast = broadcastTensors(this, other) + val newThis = broadcast[0] + val newOther = broadcast[1] + + val resBuffer = DoubleArray(newThis.strides.linearSize) { i -> + newThis.buffer.array()[newOther.bufferStart + i] * + newOther.buffer.array()[newOther.bufferStart + i] } - return DoubleTensor(this.shape, resBuffer) + return DoubleTensor(newThis.shape, resBuffer) } override fun DoubleTensor.timesAssign(value: Double) { - //todo should be change with broadcasting for (i in 0 until this.strides.linearSize) { this.buffer.array()[this.bufferStart + i] *= value } } override fun DoubleTensor.timesAssign(other: DoubleTensor) { - //todo should be change with broadcasting + val newOther = broadcastTo(other, this.shape) for (i in 0 until this.strides.linearSize) { this.buffer.array()[this.bufferStart + i] *= - other.buffer.array()[this.bufferStart + i] + newOther.buffer.array()[this.bufferStart + i] } } diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/utils.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/utils.kt index 3e32e2b72..e7e043463 100644 --- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/utils.kt +++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/tensors/utils.kt @@ -32,6 +32,43 @@ internal inline fun broadcastShapes(vararg shapes: IntArray): IntArray { return totalShape } +internal inline fun broadcastTo(tensor: DoubleTensor, newShape: IntArray): DoubleTensor { + if (tensor.shape.size > newShape.size) { + throw RuntimeException("Tensor is not compatible with the new shape") + } + + val n = newShape.reduce { acc, i -> acc * i } + val resTensor = DoubleTensor(newShape, DoubleArray(n)) + + for (i in tensor.shape.indices) { + val curDim = tensor.shape[i] + val offset = newShape.size - tensor.shape.size + if (curDim != 1 && newShape[i + offset] != curDim) { + throw RuntimeException("Tensor is not compatible with the new shape and cannot be broadcast") + } + } + + for (linearIndex in 0 until n) { + val totalMultiIndex = resTensor.strides.index(linearIndex) + val curMultiIndex = tensor.shape.copyOf() + + val offset = totalMultiIndex.size - curMultiIndex.size + + for (i in curMultiIndex.indices) { + if (curMultiIndex[i] != 1) { + curMultiIndex[i] = totalMultiIndex[i + offset] + } else { + curMultiIndex[i] = 0 + } + } + + val curLinearIndex = tensor.strides.offset(curMultiIndex) + resTensor.buffer.array()[linearIndex] = + tensor.buffer.array()[tensor.bufferStart + curLinearIndex] + } + return resTensor +} + internal inline fun broadcastTensors(vararg tensors: DoubleTensor): List { val totalShape = broadcastShapes(*(tensors.map { it.shape }).toTypedArray()) val n = totalShape.reduce { acc, i -> acc * i } diff --git a/kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/TestDoubleTensorAlgebra.kt b/kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/TestDoubleTensorAlgebra.kt index 226454bf4..a060a970f 100644 --- a/kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/TestDoubleTensorAlgebra.kt +++ b/kmath-core/src/commonTest/kotlin/space/kscience/kmath/tensors/TestDoubleTensorAlgebra.kt @@ -58,6 +58,16 @@ class TestDoubleTensorAlgebra { ) contentEquals intArrayOf(5, 6, 7)) } + @Test + fun broadcastTo() = DoubleTensorAlgebra { + val tensor1 = DoubleTensor(intArrayOf(2, 3), doubleArrayOf(1.0, 2.0, 3.0, 4.0, 5.0, 6.0)) + val tensor2 = DoubleTensor(intArrayOf(1, 3), doubleArrayOf(10.0, 20.0, 30.0)) + + val res = broadcastTo(tensor2, tensor1.shape) + assertTrue(res.shape contentEquals intArrayOf(2, 3)) + assertTrue(res.buffer.array() contentEquals doubleArrayOf(10.0, 20.0, 30.0, 10.0, 20.0, 30.0)) + } + @Test fun broadcastTensors() = DoubleTensorAlgebra { val tensor1 = DoubleTensor(intArrayOf(2, 3), doubleArrayOf(1.0, 2.0, 3.0, 4.0, 5.0, 6.0)) -- 2.34.1