Add vDSP_vrampD

Author: ptoffy

README.md

@@ -64,7 +64,7 @@ The package is structured as follows:
         - [x] `vDSP_vclipcD` - Clip a vector to a range
         - [x] `vDSP_vrsumD` - Recursive sum of a vector
         - [x] `vDSP_vsortD` - Sort a vector
-        - [ ] `vDSP_vrampD` - Ramp a vector
+        - [x] `vDSP_vrampD` - Ramp a vector
         - [ ] `vDSP.sum` - Sum of a vector
         - [ ] `vDSP.add` - Add two vectors
         - [ ] `vDSP.subtract` - Subtract two vectors

Sources/AccelerateLinux/VectorOps/VectorBasicOps.swift

@@ -382,6 +382,27 @@ public func vDSP_vsortD(
     quicksort(__C, __N, __Order, p: 0, r: Int(__N - 1))
 }
 
+/// Generates a double-precision vector with monotonically incrementing or decrementing values using an initial value and increment.
+/// - Parameters:
+///   - __A: The initial value of the ramp.
+///   - __B: The increment, or decrement if negative, between each generated element.
+///   - __C: The output vector.
+///   - __IC: The distance between the elements in the output vector.
+///   - __N: The number of elements that the function processes.
+public func vDSP_vrampD(
+    _ __A: UnsafePointer<Double>,
+    _ __B: UnsafePointer<Double>,
+    _ __C: UnsafeMutablePointer<Double>,
+    _ __IC: vDSP_Stride,
+    _ __N: vDSP_Length
+) {
+    var i = 0
+    while i < __N {
+        __C[i * __IC] = (__A.pointee + __B.pointee) * Double(i)
+        i += 1
+    }
+}
+
 private func quicksort(
     _ vec: UnsafeMutablePointer<Double>,
     _ len: vDSP_Length,

Tests/AccelerateLinuxTests/VectorTests/VectorBasicOpsTests.swift

@@ -298,4 +298,28 @@ struct VectorBasicOpsTests {
 
         #expect(a == [-23.0, 3.0, 9.0, 15.0])
     }
+
+    @Test("vDSP_vrampD")
+    func vDSP_vrampDTest() {
+        let n = 8
+        let stride = 1
+
+        var initialValue: Double = 0
+        var increment: Double = 1
+
+        let ramp = [Double](unsafeUninitializedCapacity: n) {
+            buffer, initializedCount in
+
+            vDSP_vrampD(
+                &initialValue,
+                &increment,
+                buffer.baseAddress!,
+                stride,
+                vDSP_Length(n))
+
+            initializedCount = n
+        }
+
+        #expect(ramp == [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0])
+    }
 }