100 lines
1.7 KiB
Go
100 lines
1.7 KiB
Go
package main
|
|
|
|
import (
|
|
"math/big"
|
|
"strconv"
|
|
)
|
|
|
|
func min(s, arg string) agg { return newBinop(s, opmin) }
|
|
func max(s, arg string) agg { return newBinop(s, opmax) }
|
|
func sum(s, arg string) agg { return newBinop(s, opsum) }
|
|
|
|
type binop struct {
|
|
v *big.Float
|
|
f func(a, b *big.Float) *big.Float
|
|
}
|
|
|
|
func newBinop(s string, f func(a, b *big.Float) *big.Float) *binop {
|
|
v, _ := parseFloat(s)
|
|
return &binop{v, f}
|
|
}
|
|
|
|
func (o *binop) String() string {
|
|
if o.v == nil {
|
|
return "NaN"
|
|
}
|
|
return o.v.Text('f', -1)
|
|
}
|
|
|
|
func (o *binop) merge(s string) {
|
|
v, ok := parseFloat(s)
|
|
if !ok {
|
|
return
|
|
}
|
|
o.v = o.f(o.v, v)
|
|
}
|
|
|
|
func opmin(a, b *big.Float) *big.Float {
|
|
if a != nil && (b == nil || a.Cmp(b) <= 0) {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
|
|
func opmax(a, b *big.Float) *big.Float {
|
|
if a != nil && (b == nil || a.Cmp(b) >= 0) {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
|
|
func opsum(a, b *big.Float) *big.Float {
|
|
if a == nil {
|
|
return b
|
|
} else if b == nil {
|
|
return a
|
|
}
|
|
return a.Add(a, b)
|
|
}
|
|
|
|
type meanagg struct {
|
|
v *big.Float
|
|
d float64 // actually an integer
|
|
}
|
|
|
|
func mean(s, arg string) agg {
|
|
v, ok := parseFloat(s)
|
|
if !ok {
|
|
return &meanagg{new(big.Float), 0}
|
|
}
|
|
return &meanagg{v, 1}
|
|
}
|
|
|
|
func (m *meanagg) String() string {
|
|
if m.d == 0 {
|
|
return "NaN"
|
|
}
|
|
v := new(big.Float).Quo(m.v, big.NewFloat(m.d))
|
|
return v.Text('f', -1)
|
|
}
|
|
|
|
func (m *meanagg) merge(s string) {
|
|
v, ok := parseFloat(s)
|
|
if !ok {
|
|
return
|
|
}
|
|
m.v.Add(m.v, v)
|
|
m.d++
|
|
}
|
|
|
|
func parseFloat(s string) (*big.Float, bool) {
|
|
v, _, err := big.ParseFloat(s, 0, 1000, big.ToNearestEven)
|
|
return v, err == nil
|
|
}
|
|
|
|
type counter int
|
|
|
|
func count(init, arg string) agg { return new(counter) }
|
|
func (c *counter) String() string { return strconv.Itoa(int(*c) + 1) }
|
|
func (c *counter) merge(string) { *c++ }
|