MonotoneSpline.kt

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package com.github.sanity.pav.spline
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import com.github.sanity.pav.BinarySearchResult
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import com.github.sanity.pav.Point
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import com.github.sanity.pav.betterBinarySearch
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import java.util.*
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/**
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 * Creates a monotone cubic spline from a given set of control points, implementing
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 * the algorithm described [here](https://en.wikipedia.org/wiki/Monotone_cubic_interpolation).
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 * The spline is guaranteed to pass through each control point exactly.
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 * Moreover, assuming the control points are monotonic (Y is non-decreasing or
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 * non-increasing) then the interpolated values will also be monotonic.
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 * @param xPoints The X component of the control points, strictly increasing.
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 * *
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 * @param yPoints The Y component of the control points, monotonic.
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 * *
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 * @return
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 * *
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 * *
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 * @throws IllegalArgumentException if the X or Y arrays are null, have
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 * * different lengths or have fewer than 2 values.
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 * *
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 * @throws IllegalArgumentException if the control points are not monotonic.
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*/
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class MonotoneSpline(inputPoints: List<Point>, tangentStrategy: TangentStrategy = FritschCarlsonTangentStrategy()) {
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    private val points: ArrayList<PointWithTangents>
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    init {
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        val pointsWithSecants = SecantsCalculator.calculate(inputPoints)
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        points = tangentStrategy.compute(pointsWithSecants)
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    }
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    /**
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     * Interpolates the value of Y = f(X) for given X.
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     * Clamps X to the domain of the spline.
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     * @param x The X value.
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     * *
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     * @return The interpolated Y = f(X) value.
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     */
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    fun interpolate(x: Double): Double {
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        val firstPoint = points.first()
48 3 1. interpolate : changed conditional boundary → SURVIVED
2. interpolate : negated conditional → KILLED
3. interpolate : replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
 
        if (x < firstPoint.x) return firstPoint.y
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        val lastPoint = points.last()
50 3 1. interpolate : changed conditional boundary → SURVIVED
2. interpolate : negated conditional → KILLED
3. interpolate : replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
 
        if (x > lastPoint.x) return lastPoint.y
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        val binarySearchResult = points.map { it.x }.toDoubleArray().betterBinarySearch(x)
52 1 1. interpolate : replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
 
        return when (binarySearchResult) {
53 1 1. interpolate : negated conditional → KILLED
 
            is BinarySearchResult.Exact -> points[binarySearchResult.index].y
54 1 1. interpolate : negated conditional → KILLED
 
            is BinarySearchResult.Between -> {
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                val x1 = points[binarySearchResult.lowIndex].x
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                val y1 = points[binarySearchResult.lowIndex].y
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                val m1 = points[binarySearchResult.lowIndex].tangent
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                val x2 = points[binarySearchResult.highIndex].x
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                val y2 = points[binarySearchResult.highIndex].y
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                val m2 = points[binarySearchResult.highIndex].tangent
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                val chs = CubicHermiteSpline(x1 = x1, y1 = y1, m1 = m1, x2 = x2, y2 = y2, m2 = m2)
62 1 1. interpolate : replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
 
                return chs.interpolate(x)
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            }
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            else -> TODO("Remove this, shouldn't be necessary")
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        }
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    }
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}
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Mutations

48

1.1
Location : interpolate
Killed by : none changed conditional boundary → SURVIVED

2.2
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec negated conditional → KILLED

3.3
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
50

1.1
Location : interpolate
Killed by : none changed conditional boundary → SURVIVED

2.2
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec negated conditional → KILLED

3.3
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
52

1.1
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
53

1.1
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec negated conditional → KILLED
54

1.1
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec negated conditional → KILLED
62

1.1
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec replaced return of double value with -(x + 1) for com/github/sanity/pav/spline/MonotoneSpline::interpolate → KILLED
71

1.1
Location : interpolate
Killed by : com.github.sanity.pav.spline.MonotoneSplineSpec.com.github.sanity.pav.spline.MonotoneSplineSpec negated conditional → KILLED

Active mutators

Tests examined


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