Algoritmo de etiqueta agradable para gráficos con marcas mínimas

Necesito calcular Ticklabels y Tickrange para gráficos manualmente.

Conozco el algoritmo “estándar” para los tics buenos (ver http://books.google.de/books?id=fvA7zLEFWZgC&pg=PA61&lpg=PA61&redir_esc=y#v=onepage&q&f=false ) y también conozco esta implementación de Java .

El problema es que con este algoritmo, los tics son “demasiado inteligentes”. Eso significa que el algoritmo decide la cantidad de tics que se deben mostrar. Mi requisito es que siempre haya 5 Ticks, pero estos deberían ser “bonitos”. El enfoque ingenuo sería obtener el valor máximo, dividir con 5 y multiplicar con el número de tick. Los valores aquí son, por supuesto, no óptimos y los tics son bastante feos.

¿Alguien sabe una solución para el problema o tiene una pista para una descripción formal del algoritmo?

Debería poder usar la implementación de Java con correcciones menores.

Cambiar maxticks a 5.

Cambie el método de cálculo a esto:

private void calculate() { this.range = niceNum(maxPoint - minPoint, false); this.tickSpacing = niceNum(range / (maxTicks - 1), true); this.niceMin = Math.floor(minPoint / tickSpacing) * tickSpacing; this.niceMax = this.niceMin + tickSpacing * (maxticks - 1); // Always display maxticks } 

Descargo de responsabilidad: Tenga en cuenta que no he probado esto, por lo que puede tener que modificarlo para que se vea bien. Mi solución sugerida agrega espacio extra en la parte superior de la tabla para siempre dejar espacio para 5 tics. Esto puede verse feo en algunos casos.

Soy el autor de ” Algoritmo para escalado óptimo en un eje de gráfico “. Solía ​​estar alojado en trollop.org, pero recientemente he movido dominios / motores de blogs. De todos modos, publicaré los contenidos aquí para un acceso más fácil.

He estado trabajando en una aplicación de gráficos de Android para una tarea y me encontré con un pequeño problema cuando se trataba de presentar la tabla en un formato muy bien escalado. Pasé un tiempo tratando de crear este algoritmo por mi cuenta y estuve terriblemente cerca, pero al final encontré un ejemplo de pseudocódigo en un libro llamado “Graphics Gems, Volume 1″ de Andrew S. Glassner. Una excelente descripción del problema se encuentra en el capítulo sobre ” Niza Números para Etiquetas Gráficas “:

Al crear un gráfico por computadora, es conveniente etiquetar los ejes xey con números “agradables”: números decimales simples. Por ejemplo, si el rango de datos es de 105 a 543, probablemente querríamos trazar el rango de 100 a 600 y poner marcas cada 100 unidades. O si el rango de datos es de 2.04 a 2.16, probablemente trazaríamos un rango de 2.00 a 2.20 con un espaciado de 0.05. Los humanos son buenos para elegir esos números “agradables”, pero los algoritmos simplistas no lo son. El algoritmo de selección de etiqueta ingenuo toma el rango de datos y lo divide en n intervalos iguales, pero esto generalmente da como resultado tags de tilde feas. Aquí describimos un método simple para generar buenas tags de gráficos.

La observación principal es que los números “más bonitos” en decimales son 1, 2 y 5, y todos los múltiplos del poder de diez de estos números. Usaremos solo esos números para el espaciado de las marcas y colocaremos las marcas en los múltiplos del espacio entre las marcas …

Usé el ejemplo de pseudocódigo en este libro para crear la siguiente clase en Java:

 public class NiceScale { private double minPoint; private double maxPoint; private double maxTicks = 10; private double tickSpacing; private double range; private double niceMin; private double niceMax; /** * Instantiates a new instance of the NiceScale class. * * @param min the minimum data point on the axis * @param max the maximum data point on the axis */ public NiceScale(double min, double max) { this.minPoint = min; this.maxPoint = max; calculate(); } /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ private void calculate() { this.range = niceNum(maxPoint - minPoint, false); this.tickSpacing = niceNum(range / (maxTicks - 1), true); this.niceMin = Math.floor(minPoint / tickSpacing) * tickSpacing; this.niceMax = Math.ceil(maxPoint / tickSpacing) * tickSpacing; } /** * Returns a "nice" number approximately equal to range Rounds * the number if round = true Takes the ceiling if round = false. * * @param range the data range * @param round whether to round the result * @return a "nice" number to be used for the data range */ private double niceNum(double range, boolean round) { double exponent; /** exponent of range */ double fraction; /** fractional part of range */ double niceFraction; /** nice, rounded fraction */ exponent = Math.floor(Math.log10(range)); fraction = range / Math.pow(10, exponent); if (round) { if (fraction < 1.5) niceFraction = 1; else if (fraction < 3) niceFraction = 2; else if (fraction < 7) niceFraction = 5; else niceFraction = 10; } else { if (fraction <= 1) niceFraction = 1; else if (fraction <= 2) niceFraction = 2; else if (fraction <= 5) niceFraction = 5; else niceFraction = 10; } return niceFraction * Math.pow(10, exponent); } /** * Sets the minimum and maximum data points for the axis. * * @param minPoint the minimum data point on the axis * @param maxPoint the maximum data point on the axis */ public void setMinMaxPoints(double minPoint, double maxPoint) { this.minPoint = minPoint; this.maxPoint = maxPoint; calculate(); } /** * Sets maximum number of tick marks we're comfortable with * * @param maxTicks the maximum number of tick marks for the axis */ public void setMaxTicks(double maxTicks) { this.maxTicks = maxTicks; calculate(); } } 

Entonces podemos hacer uso del código anterior de esta manera:

 NiceScale numScale = new NiceScale(-0.085, 0.173); System.out.println("Tick Spacing:\t" + numScale.getTickSpacing()); System.out.println("Nice Minimum:\t" + numScale.getNiceMin()); System.out.println("Nice Maximum:\t" + numScale.getNiceMax()); 

Que luego dará salida a números formateados para su uso en cualquier aplicación para la que necesite crear escalas bonitas. = D

 Tick Spacing: 0.05 Nice Minimum: -0.1 Nice Maximum: 0.2 

He convertido el código de java anterior a Python según mi requisito.

  import math class NiceScale: def __init__(self, minv,maxv): self.maxTicks = 6 self.tickSpacing = 0 self.lst = 10 self.niceMin = 0 self.niceMax = 0 self.minPoint = minv self.maxPoint = maxv self.calculate() def calculate(self): self.lst = self.niceNum(self.maxPoint - self.minPoint, False) self.tickSpacing = self.niceNum(self.lst / (self.maxTicks - 1), True) self.niceMin = math.floor(self.minPoint / self.tickSpacing) * self.tickSpacing self.niceMax = math.ceil(self.maxPoint / self.tickSpacing) * self.tickSpacing def niceNum(self, lst, rround): self.lst = lst exponent = 0 # exponent of range */ fraction = 0 # fractional part of range */ niceFraction = 0 # nice, rounded fraction */ exponent = math.floor(math.log10(self.lst)); fraction = self.lst / math.pow(10, exponent); if (self.lst): if (fraction < 1.5): niceFraction = 1 elif (fraction < 3): niceFraction = 2 elif (fraction < 7): niceFraction = 5; else: niceFraction = 10; else : if (fraction <= 1): niceFraction = 1 elif (fraction <= 2): niceFraction = 2 elif (fraction <= 5): niceFraction = 5 else: niceFraction = 10 return niceFraction * math.pow(10, exponent) def setMinMaxPoints(self, minPoint, maxPoint): self.minPoint = minPoint self.maxPoint = maxPoint self.calculate() def setMaxTicks(self, maxTicks): self.maxTicks = maxTicks; self.calculate() a=NiceScale(14024, 17756) print "a.lst ", a.lst print "a.maxPoint ", a.maxPoint print "a.maxTicks ", a.maxTicks print "a.minPoint ", a.minPoint print "a.niceMax ", a.niceMax print "a.niceMin ", a.niceMin print "a.tickSpacing ", a.tickSpacing 

Aquí está lo mismo en el Objetivo C

YFRNiceScale.h

 #import  @interface YFRNiceScale : NSObject @property (nonatomic, readonly) CGFloat minPoint; @property (nonatomic, readonly) CGFloat maxPoint; @property (nonatomic, readonly) CGFloat maxTicks; @property (nonatomic, readonly) CGFloat tickSpacing; @property (nonatomic, readonly) CGFloat range; @property (nonatomic, readonly) CGFloat niceRange; @property (nonatomic, readonly) CGFloat niceMin; @property (nonatomic, readonly) CGFloat niceMax; - (id) initWithMin: (CGFloat) min andMax: (CGFloat) max; - (id) initWithNSMin: (NSDecimalNumber*) min andNSMax: (NSDecimalNumber*) max; @end 

YFRNiceScale.m

 #import "YFRNiceScale.h" @implementation YFRNiceScale @synthesize minPoint = _minPoint; @synthesize maxPoint = _maxPoint; @synthesize maxTicks = _maxTicks; @synthesize tickSpacing = _tickSpacing; @synthesize range = _range; @synthesize niceRange = _niceRange; @synthesize niceMin = _niceMin; @synthesize niceMax = _niceMax; - (id)init { self = [super init]; if (self) { } return self; } - (id) initWithMin: (CGFloat) min andMax: (CGFloat) max { if (self) { _maxTicks = 10; _minPoint = min; _maxPoint = max; [self calculate]; } return [self init]; } - (id) initWithNSMin: (NSDecimalNumber*) min andNSMax: (NSDecimalNumber*) max { if (self) { _maxTicks = 10; _minPoint = [min doubleValue]; _maxPoint = [max doubleValue]; [self calculate]; } return [self init]; } /** * Calculate and update values for tick spacing and nice minimum and maximum * data points on the axis. */ - (void) calculate { _range = [self niceNumRange: (_maxPoint-_minPoint) roundResult:NO]; _tickSpacing = [self niceNumRange: (_range / (_maxTicks - 1)) roundResult:YES]; _niceMin = floor(_minPoint / _tickSpacing) * _tickSpacing; _niceMax = ceil(_maxPoint / _tickSpacing) * _tickSpacing; _niceRange = _niceMax - _niceMin; } /** * Returns a "nice" number approximately equal to range Rounds the number if * round = true Takes the ceiling if round = false. * * @param range * the data range * @param round * whether to round the result * @return a "nice" number to be used for the data range */ - (CGFloat) niceNumRange:(CGFloat) aRange roundResult:(BOOL) round { CGFloat exponent; CGFloat fraction; CGFloat niceFraction; exponent = floor(log10(aRange)); fraction = aRange / pow(10, exponent); if (round) { if (fraction < 1.5) { niceFraction = 1; } else if (fraction < 3) { niceFraction = 2; } else if (fraction < 7) { niceFraction = 5; } else { niceFraction = 10; } } else { if (fraction <= 1) { niceFraction = 1; } else if (fraction <= 2) { niceFraction = 2; } else if (fraction <= 5) { niceFraction = 2; } else { niceFraction = 10; } } return niceFraction * pow(10, exponent); } - (NSString*) description { return [NSString stringWithFormat:@"NiceScale [minPoint=%.2f, maxPoint=%.2f, maxTicks=%.2f, tickSpacing=%.2f, range=%.2f, niceMin=%.2f, niceMax=%.2f]", _minPoint, _maxPoint, _maxTicks, _tickSpacing, _range, _niceMin, _niceMax ]; } @end 

Uso:

 YFRNiceScale* niceScale = [[YFRNiceScale alloc] initWithMin:0 andMax:500]; NSLog(@"Nice: %@", niceScale); 

Encontré este hilo al escribir algunos php, ¡así que ahora el mismo código está disponible también en php!

 class CNiceScale { private $minPoint; private $maxPoint; private $maxTicks = 10; private $tickSpacing; private $range; private $niceMin; private $niceMax; public function setScale($min, $max) { $this->minPoint = $min; $this->maxPoint = $max; $this->calculate(); } private function calculate() { $this->range = $this->niceNum($this->maxPoint - $this->minPoint, false); $this->tickSpacing = $this->niceNum($this->range / ($this->maxTicks - 1), true); $this->niceMin = floor($this->minPoint / $this->tickSpacing) * $this->tickSpacing; $this->niceMax = ceil($this->maxPoint / $this->tickSpacing) * $this->tickSpacing; } private function niceNum($range, $round) { $exponent; /** exponent of range */ $fraction; /** fractional part of range */ $niceFraction; /** nice, rounded fraction */ $exponent = floor(log10($range)); $fraction = $range / pow(10, $exponent); if ($round) { if ($fraction < 1.5) $niceFraction = 1; else if ($fraction < 3) $niceFraction = 2; else if ($fraction < 7) $niceFraction = 5; else $niceFraction = 10; } else { if ($fraction <= 1) $niceFraction = 1; else if ($fraction <= 2) $niceFraction = 2; else if ($fraction <= 5) $niceFraction = 5; else $niceFraction = 10; } return $niceFraction * pow(10, $exponent); } public function setMinMaxPoints($minPoint, $maxPoint) { $this->minPoint = $minPoint; $this->maxPoint = $maxPoint; $this->calculate(); } public function setMaxTicks($maxTicks) { $this->maxTicks = $maxTicks; $this->calculate(); } public function getTickSpacing() { return $this->tickSpacing; } public function getNiceMin() { return $this->niceMin; } public function getNiceMax() { return $this->niceMax; } } 

Necesitaba este algoritmo convertido a C #, así que aquí está …

 public static class NiceScale { public static void Calculate(double min, double max, int maxTicks, out double range, out double tickSpacing, out double niceMin, out double niceMax) { range = niceNum(max - min, false); tickSpacing = niceNum(range / (maxTicks - 1), true); niceMin = Math.Floor(min / tickSpacing) * tickSpacing; niceMax = Math.Ceiling(max / tickSpacing) * tickSpacing; } private static double niceNum(double range, bool round) { double pow = Math.Pow(10, Math.Floor(Math.Log10(range))); double fraction = range / pow; double niceFraction; if (round) { if (fraction < 1.5) { niceFraction = 1; } else if (fraction < 3) { niceFraction = 2; } else if (fraction < 7) { niceFraction = 5; } else { niceFraction = 10; } } else { if (fraction <= 1) { niceFraction = 1; } else if (fraction <= 2) { niceFraction = 2; } else if (fraction <= 5) { niceFraction = 5; } else { niceFraction = 10; } } return niceFraction * pow; } } 

Aquí hay una versión de JavaScript:

 var minPoint; var maxPoint; var maxTicks = 10; var tickSpacing; var range; var niceMin; var niceMax; /** * Instantiates a new instance of the NiceScale class. * * min the minimum data point on the axis * max the maximum data point on the axis */ function niceScale( min, max) { minPoint = min; maxPoint = max; calculate(); return { tickSpacing: tickSpacing, niceMinimum: niceMin, niceMaximum: niceMax }; } /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ function calculate() { range = niceNum(maxPoint - minPoint, false); tickSpacing = niceNum(range / (maxTicks - 1), true); niceMin = Math.floor(minPoint / tickSpacing) * tickSpacing; niceMax = Math.ceil(maxPoint / tickSpacing) * tickSpacing; } /** * Returns a "nice" number approximately equal to range Rounds * the number if round = true Takes the ceiling if round = false. * * localRange the data range * round whether to round the result * a "nice" number to be used for the data range */ function niceNum( localRange, round) { var exponent; /** exponent of localRange */ var fraction; /** fractional part of localRange */ var niceFraction; /** nice, rounded fraction */ exponent = Math.floor(Math.log10(localRange)); fraction = localRange / Math.pow(10, exponent); if (round) { if (fraction < 1.5) niceFraction = 1; else if (fraction < 3) niceFraction = 2; else if (fraction < 7) niceFraction = 5; else niceFraction = 10; } else { if (fraction <= 1) niceFraction = 1; else if (fraction <= 2) niceFraction = 2; else if (fraction <= 5) niceFraction = 5; else niceFraction = 10; } return niceFraction * Math.pow(10, exponent); } /** * Sets the minimum and maximum data points for the axis. * * minPoint the minimum data point on the axis * maxPoint the maximum data point on the axis */ function setMinMaxPoints( localMinPoint, localMaxPoint) { minPoint = localMinPoint; maxPoint = localMaxoint; calculate(); } /** * Sets maximum number of tick marks we're comfortable with * * maxTicks the maximum number of tick marks for the axis */ function setMaxTicks(localMaxTicks) { maxTicks = localMaxTicks; calculate(); } 

¡Disfrutar!

Como todos y su perro publican una traducción a otros idiomas populares, esta es mi versión para el lenguaje de progtwigción Nimrod . También agregué el manejo de casos donde la cantidad de ticks es menor a dos:

 import math, strutils const defaultMaxTicks = 10 type NiceScale = object minPoint: float maxPoint: float maxTicks: int tickSpacing: float niceMin: float niceMax: float proc ff(x: float): string = result = x.formatFloat(ffDecimal, 3) proc `$`*(x: NiceScale): string = result = "Input minPoint: " & x.minPoint.ff & "\nInput maxPoint: " & x.maxPoint.ff & "\nInput maxTicks: " & $x.maxTicks & "\nOutput niceMin: " & x.niceMin.ff & "\nOutput niceMax: " & x.niceMax.ff & "\nOutput tickSpacing: " & x.tickSpacing.ff & "\n" proc calculate*(x: var NiceScale) proc init*(x: var NiceScale; minPoint, maxPoint: float; maxTicks = defaultMaxTicks) = x.minPoint = minPoint x.maxPoint = maxPoint x.maxTicks = maxTicks x.calculate proc initScale*(minPoint, maxPoint: float; maxTicks = defaultMaxTicks): NiceScale = result.init(minPoint, maxPoint, maxTicks) proc niceNum(scaleRange: float; doRound: bool): float = var exponent: float ## Exponent of scaleRange. fraction: float ## Fractional part of scaleRange. niceFraction: float ## Nice, rounded fraction. exponent = floor(log10(scaleRange)); fraction = scaleRange / pow(10, exponent); if doRound: if fraction < 1.5: niceFraction = 1 elif fraction < 3: niceFraction = 2 elif fraction < 7: niceFraction = 5 else: niceFraction = 10 else: if fraction <= 1: niceFraction = 1 elif fraction <= 2: niceFraction = 2 elif fraction <= 5: niceFraction = 5 else: niceFraction = 10 return niceFraction * pow(10, exponent) proc calculate*(x: var NiceScale) = assert x.maxPoint > x.minPoint, "Wrong input range!" assert x.maxTicks >= 0, "Sorry, can't have imaginary ticks!" let scaleRange = niceNum(x.maxPoint - x.minPoint, false) if x.maxTicks < 2: x.niceMin = floor(x.minPoint) x.niceMax = ceil(x.maxPoint) x.tickSpacing = (x.niceMax - x.niceMin) / (if x.maxTicks == 1: 2.0 else: 1.0) else: x.tickSpacing = niceNum(scaleRange / (float(x.maxTicks - 1)), true) x.niceMin = floor(x.minPoint / x.tickSpacing) * x.tickSpacing x.niceMax = ceil(x.maxPoint / x.tickSpacing) * x.tickSpacing when isMainModule: var s = initScale(57.2, 103.3) echo s 

Esta es la versión de comentario eliminado. El completo se puede leer en GitHub integrado en mi proyecto.

Esta es la versión Swift:

 class NiceScale { private var minPoint: Double private var maxPoint: Double private var maxTicks = 10 private(set) var tickSpacing: Double = 0 private(set) var range: Double = 0 private(set) var niceMin: Double = 0 private(set) var niceMax: Double = 0 init(min: Double, max: Double) { minPoint = min maxPoint = max calculate() } func setMinMaxPoints(min: Double, max: Double) { minPoint = min maxPoint = max calculate() } private func calculate() { range = niceNum(maxPoint - minPoint, round: false) tickSpacing = niceNum(range / Double((maxTicks - 1)), round: true) niceMin = floor(minPoint / tickSpacing) * tickSpacing niceMax = floor(maxPoint / tickSpacing) * tickSpacing } private func niceNum(range: Double, round: Bool) -> Double { let exponent = floor(log10(range)) let fraction = range / pow(10, exponent) let niceFraction: Double if round { if fraction <= 1.5 { niceFraction = 1 } else if fraction <= 3 { niceFraction = 2 } else if fraction <= 7 { niceFraction = 5 } else { niceFraction = 10 } } else { if fraction <= 1 { niceFraction = 1 } else if fraction <= 2 { niceFraction = 2 } else if fraction <= 5 { niceFraction = 5 } else { niceFraction = 10 } } return niceFraction * pow(10, exponent) } } 

Aquí está la versión de C ++. Como bonificación, obtienes una función que devuelve el número mínimo de puntos decimales para mostrar las tags de los puntos en el eje.

El archivo de encabezado:

 class NiceScale { public: float minPoint; float maxPoint; float maxTicks; float tickSpacing; float range; float niceMin; float niceMax; public: NiceScale() { maxTicks = 10; } /** * Instantiates a new instance of the NiceScale class. * * @param min the minimum data point on the axis * @param max the maximum data point on the axis */ NiceScale(float min, float max) { minPoint = min; maxPoint = max; calculate(); } /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ void calculate() ; /** * Returns a "nice" number approximately equal to range Rounds * the number if round = true Takes the ceiling if round = false. * * @param range the data range * @param round whether to round the result * @return a "nice" number to be used for the data range */ float niceNum(float range, boolean round) ; /** * Sets the minimum and maximum data points for the axis. * * @param minPoint the minimum data point on the axis * @param maxPoint the maximum data point on the axis */ void setMinMaxPoints(float minPoint, float maxPoint) ; /** * Sets maximum number of tick marks we're comfortable with * * @param maxTicks the maximum number of tick marks for the axis */ void setMaxTicks(float maxTicks) ; int decimals(void); }; 

Y el archivo CPP:

 /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ void NiceScale::calculate() { range = niceNum(maxPoint - minPoint, false); tickSpacing = niceNum(range / (maxTicks - 1), true); niceMin = floor(minPoint / tickSpacing) * tickSpacing; niceMax = ceil(maxPoint / tickSpacing) * tickSpacing; } /** * Returns a "nice" number approximately equal to range Rounds the number if round = true Takes the ceiling if round = false. * * @param range the data range * @param round whether to round the result * @return a "nice" number to be used for the data range */ float NiceScale::niceNum(float range, boolean round) { float exponent; /** exponent of range */ float fraction; /** fractional part of range */ float niceFraction; /** nice, rounded fraction */ exponent = floor(log10(range)); fraction = range / pow(10.f, exponent); if (round) { if (fraction < 1.5) niceFraction = 1; else if (fraction < 3) niceFraction = 2; else if (fraction < 7) niceFraction = 5; else niceFraction = 10; } else { if (fraction <= 1) niceFraction = 1; else if (fraction <= 2) niceFraction = 2; else if (fraction <= 5) niceFraction = 5; else niceFraction = 10; } return niceFraction * pow(10, exponent); } /** * Sets the minimum and maximum data points for the axis. * * @param minPoint the minimum data point on the axis * @param maxPoint the maximum data point on the axis */ void NiceScale::setMinMaxPoints(float minPoint, float maxPoint) { this->minPoint = minPoint; this->maxPoint = maxPoint; calculate(); } /** * Sets maximum number of tick marks we're comfortable with * * @param maxTicks the maximum number of tick marks for the axis */ void NiceScale::setMaxTicks(float maxTicks) { this->maxTicks = maxTicks; calculate(); } // minimum number of decimals in tick labels // use in sprintf statement: // sprintf(buf, "%.*f", decimals(), tickValue); int NiceScale::decimals(void) { float logTickX = log10(tickSpacing); if(logTickX >= 0) return 0; return (int)(abs(floor(logTickX))); } 

Esta es la versión de VB.NET.

 Public Class NiceScale Private minPoint As Double Private maxPoint As Double Private maxTicks As Double = 10 Private tickSpacing Private range As Double Private niceMin As Double Private niceMax As Double Public Sub New(min As Double, max As Double) minPoint = min maxPoint = max calculate() End Sub Private Sub calculate() range = niceNum(maxPoint - minPoint, False) tickSpacing = niceNum(range / (maxTicks - 1), True) niceMin = Math.Floor(minPoint / tickSpacing) * tickSpacing niceMax = Math.Ceiling(maxPoint / tickSpacing) * tickSpacing End Sub Private Function niceNum(range As Double, round As Boolean) As Double Dim exponent As Double '/** exponent of range */ Dim fraction As Double '/** fractional part of range */ Dim niceFraction As Double '/** nice, rounded fraction */ exponent = Math.Floor(Math.Log10(range)) fraction = range / Math.Pow(10, exponent) If round Then If (fraction < 1.5) Then niceFraction = 1 ElseIf (fraction < 3) Then niceFraction = 2 ElseIf (fraction < 7) Then niceFraction = 5 Else niceFraction = 10 End If Else If (fraction <= 1) Then niceFraction = 1 ElseIf (fraction <= 2) Then niceFraction = 2 ElseIf (fraction <= 5) Then niceFraction = 5 Else niceFraction = 10 End If End If Return niceFraction * Math.Pow(10, exponent) End Function Public Sub setMinMaxPoints(minPoint As Double, maxPoint As Double) minPoint = minPoint maxPoint = maxPoint calculate() End Sub Public Sub setMaxTicks(maxTicks As Double) maxTicks = maxTicks calculate() End Sub Public Function getTickSpacing() As Double Return tickSpacing End Function Public Function getNiceMin() As Double Return niceMin End Function Public Function getNiceMax() As Double Return niceMax End Function End Class 

¡Aquí está en TypeScript!

 /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ function calculateTicks(maxTicks: number, minPoint: number, maxPoint: number): [number, number, number] { let range = niceNum(maxPoint - minPoint, false); let tickSpacing = niceNum(range / (maxTicks - 1), true); let niceMin = Math.floor(minPoint / tickSpacing) * tickSpacing; let niceMax = Math.ceil(maxPoint / tickSpacing) * tickSpacing; let tickCount = range / tickSpacing; return [tickCount, niceMin, niceMax]; } /** * Returns a "nice" number approximately equal to range Rounds * the number if round = true Takes the ceiling if round = false. * * @param range the data range * @param round whether to round the result * @return a "nice" number to be used for the data range */ function niceNum(range: number, round: boolean): number { let exponent: number; /** exponent of range */ let fraction: number; /** fractional part of range */ let niceFraction: number; /** nice, rounded fraction */ exponent = Math.floor(Math.log10(range)); fraction = range / Math.pow(10, exponent); if (round) { if (fraction < 1.5) niceFraction = 1; else if (fraction < 3) niceFraction = 2; else if (fraction < 7) niceFraction = 5; else niceFraction = 10; } else { if (fraction <= 1) niceFraction = 1; else if (fraction <= 2) niceFraction = 2; else if (fraction <= 5) niceFraction = 5; else niceFraction = 10; } return niceFraction * Math.pow(10, exponent); } 

¡Aquí está la versión de Kotlin!

 import java.lang.Math.* /** * Instantiates a new instance of the NiceScale class. * * @param min Double The minimum data point. * @param max Double The maximum data point. */ class NiceScale(private var minPoint: Double, private var maxPoint: Double) { private var maxTicks = 15.0 private var range: Double = 0.0 var niceMin: Double = 0.0 var niceMax: Double = 0.0 var tickSpacing: Double = 0.0 init { calculate() } /** * Calculate and update values for tick spacing and nice * minimum and maximum data points on the axis. */ private fun calculate() { range = niceNum(maxPoint - minPoint, false) tickSpacing = niceNum(range / (maxTicks - 1), true) niceMin = floor(minPoint / tickSpacing) * tickSpacing niceMax = ceil(maxPoint / tickSpacing) * tickSpacing } /** * Returns a "nice" number approximately equal to range. Rounds * the number if round = true. Takes the ceiling if round = false. * * @param range Double The data range. * @param round Boolean Whether to round the result. * @return Double A "nice" number to be used for the data range. */ private fun niceNum(range: Double, round: Boolean): Double { /** Exponent of range */ val exponent: Double = floor(log10(range)) /** Fractional part of range */ val fraction: Double /** Nice, rounded fraction */ val niceFraction: Double fraction = range / pow(10.0, exponent) niceFraction = if (round) { when { fraction < 1.5 -> 1.0 fraction < 3 -> 2.0 fraction < 7 -> 5.0 else -> 10.0 } } else { when { fraction <= 1 -> 1.0 fraction <= 2 -> 2.0 fraction <= 5 -> 5.0 else -> 10.0 } } return niceFraction * pow(10.0, exponent) } /** * Sets the minimum and maximum data points. * * @param minPoint Double The minimum data point. * @param maxPoint Double The maximum data point. */ fun setMinMaxPoints(minPoint: Double, maxPoint: Double) { this.minPoint = minPoint this.maxPoint = maxPoint calculate() } /** * Sets maximum number of tick marks we're comfortable with. * * @param maxTicks Double The maximum number of tick marks. */ fun setMaxTicks(maxTicks: Double) { this.maxTicks = maxTicks calculate() } }