/*
c:\users\ebata\tomioka3b\src\others\main41.go
2次元スプライン関数を使用して、緯度と経度のペアに対応する目的地までの時間を計算します。
*/
package main
import (
"fmt"
"sort"
)
// スプライン補間用の関数
func splineInterpolation(dataSet [][]float64) func(float64, float64) float64 {
n := len(dataSet)
// xの値を昇順にソートする
sort.Slice(dataSet, func(i, j int) bool {
return dataSet[i][0] < dataSet[j][0]
})
// トリディアゴナル行列を作成
h := make([]float64, n-1)
for i := 0; i < n-1; i++ {
h[i] = dataSet[i+1][0] - dataSet[i][0]
}
// 2階微分の値を計算
delta := make([]float64, n)
for i := 1; i < n-1; i++ {
delta[i] = (dataSet[i+1][1]-dataSet[i][1])/h[i] - (dataSet[i][1]-dataSet[i-1][1])/h[i-1]
}
// トリディアゴナル行列を解く
m := make([]float64, n)
l := make([]float64, n)
zArray := make([]float64, n)
l[0] = 1
for i := 1; i < n-1; i++ {
l[i] = 2*(dataSet[i+1][0]-dataSet[i-1][0]) - h[i-1]*m[i-1]
m[i] = h[i] / l[i]
zArray[i] = (delta[i] - h[i-1]*zArray[i-1]) / l[i]
}
l[n-1] = 1
zArray[n-1] = 0
c := make([]float64, n)
b := make([]float64, n)
d := make([]float64, n)
for j := n - 2; j >= 0; j-- {
c[j] = zArray[j] - m[j]*c[j+1]
b[j] = (dataSet[j+1][1]-dataSet[j][1])/h[j] - h[j]*(c[j+1]+2*c[j])/3
d[j] = (c[j+1] - c[j]) / (3 * h[j])
}
// 補間関数を返す
return func(xVal, yVal float64) float64 {
// xの範囲を確認
if xVal < dataSet[0][0] || xVal > dataSet[n-1][0] {
panic("x value is out of range")
}
// 対応するiを探す
i := 0
for i < n-1 && dataSet[i+1][0] <= xVal {
i++
}
// スプライン補間を計算
dx := xVal - dataSet[i][0]
return dataSet[i][2] + b[i]*dx + c[i]*dx*dx + d[i]*dx*dx*dx
}
}
func main() {
// データ点の定義
dataSet := [][]float64{
{35.7281578, 139.7680665, 73},
{35.7214573, 139.7754384, 63},
{35.7141672, 139.7748342, 57},
{35.7075171, 139.7564025, 67},
{35.698383, 139.7704968, 65},
{35.6997175, 139.7618655, 61},
{35.7020484, 139.7509267, 66},
{35.6918216, 139.7683569, 63},
{35.6812362, 139.7645499, 57},
{35.6750133, 139.7604455, 59},
{35.666379, 139.7557649, 55},
{35.6553809, 139.754554, 54},
{35.6457361, 139.7449875, 54},
{35.6284713, 139.7361848, 43},
{35.6208763, 139.7405387, 50},
{35.6147448, 139.7412068, 49},
{35.6086671, 139.7426731, 45},
{35.6052508, 139.7421627, 50},
{35.5983959, 139.7391046, 50},
{35.58754, 139.7355111, 51},
{35.5788485, 139.7348961, 40},
{35.5721351, 139.7318494, 53},
{35.5666392, 139.7281759, 53},
{35.5613144, 139.7215761, 33},
{35.5446458, 139.7493338, 46},
{35.5329877, 139.6982966, 30},
{35.5348941, 139.7449763, 42},
{35.5229857, 139.6889874, 41},
{35.5179115, 139.6811867, 40},
{35.5071467, 139.677526, 34},
{35.4998507, 139.6713032, 31},
{35.4923606, 139.6622968, 30},
{35.4852628, 139.6544734, 29},
{35.4846744, 139.6452731, 32},
{35.4808759, 139.6394986, 26},
{35.4763238, 139.631979, 30},
{35.4688634, 139.6268306, 32},
{35.4659811, 139.6194871, 20},
{35.4571602, 139.6199226, 27},
{35.4464751, 139.6235656, 25},
{35.436673, 139.6217708, 24},
{35.4334892, 139.6206713, 18},
{35.4314711, 139.6030542, 16},
{35.424238, 139.5927802, 17},
{35.4201765, 139.586678, 14},
{35.413768, 139.582819, 10},
{35.3819518, 139.6165374, 3},
{35.4091204, 139.5781752, 7},
{35.3966138, 139.6051573, 4},
{35.3645904, 139.6267988, 1},
{35.3428573, 139.6190711, 3},
{35.3314185, 139.6176347, 6},
{35.330416, 139.6295796, 17},
{35.3337822, 139.630869, 18},
{35.3407534, 139.6332478, 18},
{35.3400425, 139.6390968, 20},
{35.323276, 139.6151587, 13},
{35.2973885, 139.5758056, 31},
{35.3158184, 139.6222558, 15},
{35.312573, 139.6250891, 16},
{35.308405, 139.628248, 17},
{35.2825803, 139.6405151, 19},
{35.2916167, 139.6283632, 17},
{35.277848, 139.6379121, 21},
{35.2802815, 139.6599103, 19},
{35.2786985, 139.6674653, 20},
{35.2616259, 139.6679659, 26},
{35.2635438, 139.6841348, 23},
{35.2482969, 139.6775595, 25},
{35.2509382, 139.712402, 30},
{35.2315701, 139.699661, 29},
{35.2120725, 139.6824547, 33},
{35.2055645, 139.671602, 44},
{35.1986888, 139.663162, 37},
{35.1880928, 139.6507295, 39},
{35.1775554, 139.6306392, 42},
}
// スプライン補間関数を作成
interpolatedFunction := splineInterpolation(dataSet)
// 特定の座標で補間された値を計算
xValue := 35.4688634
yValue := 139.6268306
xValue, yValue = 35.7214573, 139.7754384
interpolatedValue := interpolatedFunction(xValue, yValue)
// 結果の出力
fmt.Printf("補間された値: %.2f\n", interpolatedValue)
}
