Such as: data frame a

A

V1 V2 V3

1-0.4-1.4 2.4


2, 3.3, 3.4 to 1.42


3 3.75 1.3 5.76

All of the data frame in a numerical processing, the value of less than zero zero instead, greater than zero value, value instead of quadratic then subtract 0.001, finally to generate a new data frame, how to write code? Would you help me write the? Thank you for the