atan(n) {
if (typeof n != 'object' || BigNumber.isBigNumber(n)) {
n = BigNumber.isBigNumber(n) == true ? n.toNumber() : n
n = [n]
}
let result = []
for (var i = 0; i < n.length; i++) {
result.push(Math.atan(n[i]).toFixed(15))
}
return result.length == 1 ? result[0] : result
}