How to convert from Matrix to [Double] efficiently #5
Description
Dear team,
I am learning a lot with your class about Accelerate!. I would like to ask you about how to reshape a Matrix to a Vector concatenating rows. Could you add a reshape function for this?
Example:
/* Converts the matrix into a 2-dimensional array. */
public var array: [[Double]] {
var a = [[Double]](repeating: [Double](repeating: 0, count: columns), count: rows)
for r in 0..<rows {
for c in 0..<columns {
a[r][c] = self[r, c]
}
}
return a
}
Needed:
/* Converts the matrix into a 1-dimensional array. */
I suggest you some additions that I have included by myself:
// MARK: - PERSONAL FUNCTIONS
extension Matrix{
// MARK: - Trigonometry
/* Computes the sin of the Matrix */
public func sin() -> Matrix {
var result = self
grid.withUnsafeBufferPointer { src in
result.grid.withUnsafeMutableBufferPointer { dst in
var size = Int32(rows * columns)
vvsin(dst.baseAddress!, src.baseAddress!, &size)
}
}
return result
}
// MARK: - Thresholds
//Sets to zero the values <= to the threshold
public func thresholdZero(lhs: Double) -> Matrix {
var results = self
grid.withUnsafeBufferPointer { src in
results.grid.withUnsafeMutableBufferPointer { dst in
var scalar = lhs
vDSP_vthresD(src.baseAddress!, 1, &scalar, dst.baseAddress!, 1, vDSP_Length(rows * columns))
}
}
return results
}
//Sets to a +Scalar or the values <= to the threshold and -Scalar the others
public func thresholdValue(lhs: Double, sca: Double) -> Matrix {
var results = self
grid.withUnsafeBufferPointer { src in
results.grid.withUnsafeMutableBufferPointer { dst in
var scalar = lhs
var value = sca
vDSP_vthrscD(src.baseAddress!, 1, &scalar, &value, dst.baseAddress!, 1, vDSP_Length(rows * columns))
}
}
return results
}
}