# Contour plots

Summary: This example shows how to create contour plot in F#.

Let's first create some data for the purpose of creating example charts:

open System
open Plotly.NET

// Generate linearly spaced vector
let linspace (min, max, n) =
if n <= 2 then
failwithf "n needs to be larger then 2"

let bw = float (max - min) / (float n - 1.)
[| min..bw..max |]

// Create example data
let size = 100
let x = linspace (-2. * Math.PI, 2. * Math.PI, size)
let y = linspace (-2. * Math.PI, 2. * Math.PI, size)

let f x y = -(5. * x / (x ** 2. + y ** 2. + 1.))

let z = Array.init size (fun i -> Array.init size (fun j -> f x.[j] y.[i]))


A contour plot is a graphical technique for representing a 3-dimensional surface by plotting constant z slices, called contours, on a 2-dimensional format. That is, given a value for z, lines are drawn for connecting the (x,y) coordinates where that z value occurs.

The contour plot is an alternative to a 3-D surface plot.

let contour1 = Chart.Contour(zData = z) |> Chart.withSize (600., 600.)


## Smooth Contour Coloring

To apply heatmap gradient coloring between each contour level, set the ContourColoring to heatmap:

let contour2 =
Chart.Contour(zData = z, ContoursColoring = StyleParam.ContourColoring.Heatmap)


## Contour Line Labels

Use ContourLabelFont to set a contour label font, and display the labels with ShowContourLabels:

let contour3 =
Chart.Contour(
zData = z,
ContoursColoring = StyleParam.ContourColoring.Heatmap,
ShowContourLabels = true,
ContourLabelFont = Font.init (Size = 12., Color = Color.fromKeyword White)
)

namespace Plotly
namespace Plotly.NET
module Defaults from Plotly.NET
<summary> Contains mutable global default values. Changing these values will apply the default values to all consecutive Chart generations. </summary>
val mutable DefaultDisplayOptions: DisplayOptions
Multiple items
type DisplayOptions = inherit DynamicObj new: unit -> DisplayOptions static member addAdditionalHeadTags: additionalHeadTags: XmlNode list -> (DisplayOptions -> DisplayOptions) static member addDescription: description: XmlNode list -> (DisplayOptions -> DisplayOptions) static member combine: first: DisplayOptions -> second: DisplayOptions -> DisplayOptions static member getAdditionalHeadTags: displayOpts: DisplayOptions -> XmlNode list static member getDescription: displayOpts: DisplayOptions -> XmlNode list static member getPlotlyReference: displayOpts: DisplayOptions -> PlotlyJSReference static member init: ?AdditionalHeadTags: XmlNode list * ?Description: XmlNode list * ?PlotlyJSReference: PlotlyJSReference -> DisplayOptions static member initCDNOnly: unit -> DisplayOptions ...

--------------------
new: unit -> DisplayOptions
static member DisplayOptions.init: ?AdditionalHeadTags: Giraffe.ViewEngine.HtmlElements.XmlNode list * ?Description: Giraffe.ViewEngine.HtmlElements.XmlNode list * ?PlotlyJSReference: PlotlyJSReference -> DisplayOptions
type PlotlyJSReference = | CDN of string | Full | Require of string | NoReference
<summary> Sets how plotly is referenced in the head of html docs. </summary>
union case PlotlyJSReference.NoReference: PlotlyJSReference
namespace System
val linspace: min: float * max: float * n: int -> float[]
val min: float
val max: float
val n: int
val failwithf: format: Printf.StringFormat<'T,'Result> -> 'T
<summary>Print to a string buffer and raise an exception with the given result. Helper printers must return strings.</summary>
<param name="format">The formatter.</param>
<returns>The formatted result.</returns>
<example>See <c>Printf.failwithf</c> (link: <see cref="M:Microsoft.FSharp.Core.PrintfModule.PrintFormatToStringThenFail2" />) for examples.</example>
val bw: float
Multiple items
val float: value: 'T -> float (requires member op_Explicit)
<summary>Converts the argument to 64-bit float. This is a direct conversion for all primitive numeric types. For strings, the input is converted using <c>Double.Parse()</c> with InvariantCulture settings. Otherwise the operation requires an appropriate static conversion method on the input type.</summary>
<param name="value">The input value.</param>
<returns>The converted float</returns>
<example id="float-example"><code lang="fsharp"></code></example>

--------------------
[<Struct>] type float = Double
<summary>An abbreviation for the CLI type <see cref="T:System.Double" />.</summary>
<category>Basic Types</category>

--------------------
type float<'Measure> = float
<summary>The type of double-precision floating point numbers, annotated with a unit of measure. The unit of measure is erased in compiled code and when values of this type are analyzed using reflection. The type is representationally equivalent to <see cref="T:System.Double" />.</summary>
<category index="6">Basic Types with Units of Measure</category>
val size: int
val x: float[]
type Math = static member Abs: value: decimal -> decimal + 7 overloads static member Acos: d: float -> float static member Acosh: d: float -> float static member Asin: d: float -> float static member Asinh: d: float -> float static member Atan: d: float -> float static member Atan2: y: float * x: float -> float static member Atanh: d: float -> float static member BigMul: a: int * b: int -> int64 + 2 overloads static member BitDecrement: x: float -> float ...
<summary>Provides constants and static methods for trigonometric, logarithmic, and other common mathematical functions.</summary>
field Math.PI: float = 3.14159265359
val y: float[]
val f: x: float -> y: float -> float
val x: float
val y: float
val z: float[][]
type Array = interface ICollection interface IEnumerable interface IList interface IStructuralComparable interface IStructuralEquatable interface ICloneable member Clone: unit -> obj member CopyTo: array: Array * index: int -> unit + 1 overload member GetEnumerator: unit -> IEnumerator member GetLength: dimension: int -> int ...
<summary>Provides methods for creating, manipulating, searching, and sorting arrays, thereby serving as the base class for all arrays in the common language runtime.</summary>
val init: count: int -> initializer: (int -> 'T) -> 'T[]
<summary>Creates an array given the dimension and a generator function to compute the elements.</summary>
<param name="count">The number of elements to initialize.</param>
<param name="initializer">The function to generate the initial values for each index.</param>
<returns>The created array.</returns>
<exception cref="T:System.ArgumentException">Thrown when count is negative.</exception>
<example id="init-1"><code lang="fsharp"> Array.init 4 (fun v -&gt; v + 5) </code> Evaluates to <c>[| 5; 6; 7; 8 |]</c></example>
<example id="init-2"><code lang="fsharp"> Array.init -5 (fun v -&gt; v + 5) </code> Throws <c>ArgumentException</c></example>
val i: int
val j: int
val contour1: GenericChart.GenericChart
type Chart = static member AnnotatedHeatmap: zData: seq<#seq<'a1>> * annotationText: seq<#seq<string>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?X: seq<'a3> * ?MultiX: seq<seq<'a3>> * ?XGap: int * ?Y: seq<'a4> * ?MultiY: seq<seq<'a4>> * ?YGap: int * ?Text: 'a5 * ?MultiText: seq<'a5> * ?ColorBar: ColorBar * ?ColorScale: Colorscale * ?ShowScale: bool * ?ReverseScale: bool * ?ZSmooth: SmoothAlg * ?Transpose: bool * ?UseWebGL: bool * ?ReverseYAxis: bool * ?UseDefaults: bool -> GenericChart (requires 'a1 :> IConvertible and 'a3 :> IConvertible and 'a4 :> IConvertible and 'a5 :> IConvertible) + 1 overload static member Area: x: seq<#IConvertible> * y: seq<#IConvertible> * ?ShowMarkers: bool * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?MultiOpacity: seq<float> * ?Text: 'a2 * ?MultiText: seq<'a2> * ?TextPosition: TextPosition * ?MultiTextPosition: seq<TextPosition> * ?MarkerColor: Color * ?MarkerColorScale: Colorscale * ?MarkerOutline: Line * ?MarkerSymbol: MarkerSymbol * ?MultiMarkerSymbol: seq<MarkerSymbol> * ?Marker: Marker * ?LineColor: Color * ?LineColorScale: Colorscale * ?LineWidth: float * ?LineDash: DrawingStyle * ?Line: Line * ?AlignmentGroup: string * ?OffsetGroup: string * ?StackGroup: string * ?Orientation: Orientation * ?GroupNorm: GroupNorm * ?FillColor: Color * ?FillPatternShape: PatternShape * ?FillPattern: Pattern * ?UseWebGL: bool * ?UseDefaults: bool -> GenericChart (requires 'a2 :> IConvertible) + 1 overload static member Bar: values: seq<#IConvertible> * ?Keys: seq<'a1> * ?MultiKeys: seq<seq<'a1>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?MultiOpacity: seq<float> * ?Text: 'a2 * ?MultiText: seq<'a2> * ?MarkerColor: Color * ?MarkerColorScale: Colorscale * ?MarkerOutline: Line * ?MarkerPatternShape: PatternShape * ?MultiMarkerPatternShape: seq<PatternShape> * ?MarkerPattern: Pattern * ?Marker: Marker * ?Base: #IConvertible * ?Width: 'a4 * ?MultiWidth: seq<'a4> * ?TextPosition: TextPosition * ?MultiTextPosition: seq<TextPosition> * ?UseDefaults: bool -> GenericChart (requires 'a1 :> IConvertible and 'a2 :> IConvertible and 'a4 :> IConvertible) + 1 overload static member BoxPlot: ?X: seq<'a0> * ?MultiX: seq<seq<'a0>> * ?Y: seq<'a1> * ?MultiY: seq<seq<'a1>> * ?Name: string * ?ShowLegend: bool * ?Text: 'a2 * ?MultiText: seq<'a2> * ?FillColor: Color * ?MarkerColor: Color * ?Marker: Marker * ?Opacity: float * ?WhiskerWidth: float * ?BoxPoints: BoxPoints * ?BoxMean: BoxMean * ?Jitter: float * ?PointPos: float * ?Orientation: Orientation * ?OutlineColor: Color * ?OutlineWidth: float * ?Outline: Line * ?AlignmentGroup: string * ?OffsetGroup: string * ?Notched: bool * ?NotchWidth: float * ?QuartileMethod: QuartileMethod * ?UseDefaults: bool -> GenericChart (requires 'a0 :> IConvertible and 'a1 :> IConvertible and 'a2 :> IConvertible) + 2 overloads static member Bubble: x: seq<#IConvertible> * y: seq<#IConvertible> * sizes: seq<int> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?MultiOpacity: seq<float> * ?Text: 'a2 * ?MultiText: seq<'a2> * ?TextPosition: TextPosition * ?MultiTextPosition: seq<TextPosition> * ?MarkerColor: Color * ?MarkerColorScale: Colorscale * ?MarkerOutline: Line * ?MarkerSymbol: MarkerSymbol * ?MultiMarkerSymbol: seq<MarkerSymbol> * ?Marker: Marker * ?LineColor: Color * ?LineColorScale: Colorscale * ?LineWidth: float * ?LineDash: DrawingStyle * ?Line: Line * ?AlignmentGroup: string * ?OffsetGroup: string * ?StackGroup: string * ?Orientation: Orientation * ?GroupNorm: GroupNorm * ?UseWebGL: bool * ?UseDefaults: bool -> GenericChart (requires 'a2 :> IConvertible) + 1 overload static member Candlestick: open : seq<#IConvertible> * high: seq<#IConvertible> * low: seq<#IConvertible> * close: seq<#IConvertible> * ?X: seq<'a4> * ?MultiX: seq<seq<'a4>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?Text: 'a5 * ?MultiText: seq<'a5> * ?Line: Line * ?IncreasingColor: Color * ?Increasing: FinanceMarker * ?DecreasingColor: Color * ?Decreasing: FinanceMarker * ?WhiskerWidth: float * ?ShowXAxisRangeSlider: bool * ?UseDefaults: bool -> GenericChart (requires 'a4 :> IConvertible and 'a5 :> IConvertible) + 2 overloads static member Column: values: seq<#IConvertible> * ?Keys: seq<'a1> * ?MultiKeys: seq<seq<'a1>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?MultiOpacity: seq<float> * ?Text: 'a2 * ?MultiText: seq<'a2> * ?MarkerColor: Color * ?MarkerColorScale: Colorscale * ?MarkerOutline: Line * ?MarkerPatternShape: PatternShape * ?MultiMarkerPatternShape: seq<PatternShape> * ?MarkerPattern: Pattern * ?Marker: Marker * ?Base: #IConvertible * ?Width: 'a4 * ?MultiWidth: seq<'a4> * ?TextPosition: TextPosition * ?MultiTextPosition: seq<TextPosition> * ?UseDefaults: bool -> GenericChart (requires 'a1 :> IConvertible and 'a2 :> IConvertible and 'a4 :> IConvertible) + 1 overload static member Contour: zData: seq<#seq<'b>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?X: seq<'c> * ?MultiX: seq<seq<'c>> * ?Y: seq<'d> * ?MultiY: seq<seq<'d>> * ?Text: 'e * ?MultiText: seq<'e> * ?ColorBar: ColorBar * ?ColorScale: Colorscale * ?ShowScale: bool * ?ReverseScale: bool * ?Transpose: bool * ?ContourLineColor: Color * ?ContourLineDash: DrawingStyle * ?ContourLineSmoothing: float * ?ContourLine: Line * ?ContoursColoring: ContourColoring * ?ContoursOperation: ConstraintOperation * ?ContoursType: ContourType * ?ShowContourLabels: bool * ?ContourLabelFont: Font * ?Contours: Contours * ?FillColor: Color * ?NContours: int * ?UseDefaults: bool -> GenericChart (requires 'b :> IConvertible and 'c :> IConvertible and 'd :> IConvertible and 'e :> IConvertible) static member Funnel: x: seq<#IConvertible> * y: seq<#IConvertible> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?Width: float * ?Offset: float * ?Text: 'a2 * ?MultiText: seq<'a2> * ?TextPosition: TextPosition * ?MultiTextPosition: seq<TextPosition> * ?Orientation: Orientation * ?AlignmentGroup: string * ?OffsetGroup: string * ?MarkerColor: Color * ?MarkerOutline: Line * ?Marker: Marker * ?TextInfo: TextInfo * ?ConnectorLineColor: Color * ?ConnectorLineStyle: DrawingStyle * ?ConnectorFillColor: Color * ?ConnectorLine: Line * ?Connector: FunnelConnector * ?InsideTextFont: Font * ?OutsideTextFont: Font * ?UseDefaults: bool -> GenericChart (requires 'a2 :> IConvertible) static member Heatmap: zData: seq<#seq<'a1>> * ?X: seq<'a2> * ?MultiX: seq<seq<'a2>> * ?Y: seq<'a3> * ?MultiY: seq<seq<'a3>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?XGap: int * ?YGap: int * ?Text: 'a4 * ?MultiText: seq<'a4> * ?ColorBar: ColorBar * ?ColorScale: Colorscale * ?ShowScale: bool * ?ReverseScale: bool * ?ZSmooth: SmoothAlg * ?Transpose: bool * ?UseWebGL: bool * ?ReverseYAxis: bool * ?UseDefaults: bool -> GenericChart (requires 'a1 :> IConvertible and 'a2 :> IConvertible and 'a3 :> IConvertible and 'a4 :> IConvertible) + 1 overload ...
static member Chart.Contour: zData: seq<#seq<'b>> * ?Name: string * ?ShowLegend: bool * ?Opacity: float * ?X: seq<'c> * ?MultiX: seq<seq<'c>> * ?Y: seq<'d> * ?MultiY: seq<seq<'d>> * ?Text: 'e * ?MultiText: seq<'e> * ?ColorBar: ColorBar * ?ColorScale: StyleParam.Colorscale * ?ShowScale: bool * ?ReverseScale: bool * ?Transpose: bool * ?ContourLineColor: Color * ?ContourLineDash: StyleParam.DrawingStyle * ?ContourLineSmoothing: float * ?ContourLine: Line * ?ContoursColoring: StyleParam.ContourColoring * ?ContoursOperation: StyleParam.ConstraintOperation * ?ContoursType: StyleParam.ContourType * ?ShowContourLabels: bool * ?ContourLabelFont: Font * ?Contours: TraceObjects.Contours * ?FillColor: Color * ?NContours: int * ?UseDefaults: bool -> GenericChart.GenericChart (requires 'b :> IConvertible and 'c :> IConvertible and 'd :> IConvertible and 'e :> IConvertible)
static member Chart.withSize: width: float * height: float -> (GenericChart.GenericChart -> GenericChart.GenericChart)
static member Chart.withSize: ?Width: int * ?Height: int -> (GenericChart.GenericChart -> GenericChart.GenericChart)
module GenericChart from Plotly.NET
<summary> Module to represent a GenericChart </summary>
val toChartHTML: gChart: GenericChart.GenericChart -> string
val contour2: GenericChart.GenericChart
module StyleParam from Plotly.NET
type ContourColoring = | Fill | Heatmap | Lines | NoColoring member Convert: unit -> obj override ToString: unit -> string static member convert: (ContourColoring -> obj) static member toString: (ContourColoring -> string)
union case StyleParam.ContourColoring.Heatmap: StyleParam.ContourColoring
val contour3: GenericChart.GenericChart
Multiple items
type Font = inherit DynamicObj new: unit -> Font static member init: ?Family: FontFamily * ?Size: float * ?Color: Color -> Font static member style: ?Family: FontFamily * ?Size: float * ?Color: Color -> (Font -> Font)
<summary> Font type inherits from dynamic object </summary>

--------------------
new: unit -> Font
static member Font.init: ?Family: StyleParam.FontFamily * ?Size: float * ?Color: Color -> Font
type Color = override Equals: other: obj -> bool override GetHashCode: unit -> int static member fromARGB: a: int -> r: int -> g: int -> b: int -> Color static member fromColorScaleValues: c: seq<#IConvertible> -> Color static member fromColors: c: seq<Color> -> Color static member fromHex: s: string -> Color static member fromKeyword: c: ColorKeyword -> Color static member fromRGB: r: int -> g: int -> b: int -> Color static member fromString: c: string -> Color member Value: obj
<summary> Plotly color can be a single color, a sequence of colors, or a sequence of numeric values referencing the color of the colorscale obj </summary>
static member Color.fromKeyword: c: ColorKeyword -> Color
union case ColorKeyword.White: ColorKeyword