71 lines
1.4 KiB
Go
71 lines
1.4 KiB
Go
// Copyright © 2016 Abcum Ltd
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package math
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import "math"
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func Percentile(vals []float64, percent float64) float64 {
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if len(vals) == 0 {
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return math.NaN()
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}
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if percent <= 0 || percent > 100 {
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return math.NaN()
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}
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sort := Sort(vals)
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size := Size(vals)
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indx := (percent / 100) * float64(size)
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switch {
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case indx == Whole(indx):
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i := int(indx)
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return sort[i-1]
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case indx > 1:
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i := int(indx)
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return Mean([]float64{sort[i-1], sort[i]})
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default:
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return math.NaN()
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}
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}
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func NearestRankPercentile(vals []float64, percent float64) float64 {
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if len(vals) == 0 {
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return math.NaN()
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}
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if percent <= 0 || percent > 100 {
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return math.NaN()
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}
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sort := Sort(vals)
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size := Size(vals)
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if percent == 100 {
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return sort[size-1]
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}
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r := int(math.Ceil(float64(size) * percent / 100))
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if r == 0 {
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return sort[0]
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}
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return sort[r-1]
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}
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