Question

关注这个SO question什么是使用格式化运算符将其应用于numpy数组的最佳方法，其中数组的格式如下所示，对应RGB值

注意RGB值已经缩放为0到1，所以多次乘以255来重新缩放

func longPressDetected(_ sender: Any){

    let longPress:UILongPressGestureRecognizer = sender as! UILongPressGestureRecognizer
    let state:UIGestureRecognizerState = longPress.state

    let location:CGPoint = longPress.location(in: self.tableView) as CGPoint
    let indexPath = self.tableView.indexPathForRow(at: location)

    var snapshot:UIView!
    var sourceIndexPath:NSIndexPath?

    if (holderView) != nil{
        snapshot = holderView
    }

    if (beginningIndexPath) != nil{
        sourceIndexPath = beginningIndexPath
    }


    switch(state){

        case UIGestureRecognizerState.began:
            if let test = indexPath{
                sourceIndexPath = indexPath! as NSIndexPath
                beginningIndexPath = sourceIndexPath
                let cell:UITableViewCell = self.tableView.cellForRow(at: test)!
                snapshot = self.customSnapShotFrom(view: cell)
                holderView = snapshot

                var center:CGPoint = cell.center
                snapshot.center = center
                snapshot.alpha = 0.0
                self.tableView.addSubview(snapshot)

                UIView.animate(withDuration: 0.25, animations:{
                    center.y = location.y
                    snapshot.center = center
                    snapshot.transform = CGAffineTransform(scaleX: 1.05, y: 1.05)
                    snapshot.alpha = 0.98
                    cell.alpha = 0.0
                },completion:{ _ in
                    cell.isHidden = true})
            }
        break

        case UIGestureRecognizerState.changed:
            // print("changed")
            var center:CGPoint = snapshot.center
            center.y = location.y
            snapshot.center = center

            if let test = indexPath {

                let bool = indexPath!.elementsEqual(beginningIndexPath as IndexPath)

                if !bool {

                    self.updatePriorities(draggedOverIndexPath: test as NSIndexPath)

                }
            }
        default:
            // print("finished")
            let cell:UITableViewCell = self.tableView.cellForRow(at: sourceIndexPath as! IndexPath)!
            cell.isHidden = false
            cell.alpha = 0.0


            UIView.animate(withDuration: 0.25, animations: {


                snapshot.center = cell.center;
                snapshot.transform = .identity
                snapshot.alpha = 0.0;
                cell.alpha = 1.0;

            }, completion: { _ in

                sourceIndexPath = nil
                snapshot.removeFromSuperview()
                snapshot = nil
            })

        }
}

    func customSnapShotFrom(view:UIView) -> UIView {

    let snapshot:UIView = view.snapshotView(afterScreenUpdates: true)!
    snapshot.layer.masksToBounds = false;
    snapshot.layer.cornerRadius = 0.0;
    snapshot.layer.shadowOffset = CGSize(width: 2.0, height: 2.0);
    snapshot.layer.shadowRadius = 4.0;
    snapshot.layer.shadowOpacity = 1.0;

    return snapshot;
}


func updatePriorities(draggedOverIndexPath:NSIndexPath) {
    let firstItem: Person = fetchedResultsController.object(at: beginningIndexPath as IndexPath)
    let secondItem: Person = fetchedResultsController.object(at: draggedOverIndexPath as IndexPath)

    firstItem.priority = Int32(draggedOverIndexPath.row)
    secondItem.priority = Int32(beginningIndexPath.row)

    beginningIndexPath = draggedOverIndexPath

    coreDataStack.saveContext()

}

并且您希望每行hex triplet值

Answer 1

您可以使用matplotlib中的rgb2hex。

from matplotlib.colors import rgb2hex

[ rgb2hex(A[i,:]) for i in range(A.shape[0]) ]
# ['#687847', '#979b8d', '#706d59', '#6a734d', '#8b5e66', '#5e5051']

如果您不想使用matplotlib函数，则需要在使用引用的SO答案之前将数组转换为int。请注意，输出略有不同，我认为是由于舍入误差造成的。

B = np.array(A*255, dtype=int) # convert to int

# Define a function for the mapping
rgb2hex = lambda r,g,b: '#%02x%02x%02x' %(r,g,b)

[ rgb2hex(*B[i,:]) for i in range(B.shape[0]) ]
# ['#687846', '#979a8d', '#706d59', '#6a734d', '#8a5e66', '#5e5050']

使用格式运算符％将numpy RGB值数组转换为十六进制

1 个答案: