在给定的进动下获得下一个更大/更小的数字

Question

具有双精度数和所需的舍入数，如何获得下一个bigger/smaller rounded number？

示例

N = 10.476
Prec = 0.25
Smaller = 10.25
Bigger = 10.50

N = 0.837
Prec = 0.005
Smaller = 0.835
Bigger = 0.840

Answer 1

def round_smaller(n, prec)
  (n / prec).floor * prec
end

def round_bigger(n, prec)
  (n / prec).ceil * prec
end