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altitudeEnvelopeContour

Draw altitude envelope contour plot

Description

Draw Contour Plots with Load Factors and Meshes

example

altitudeEnvelopeContour(loadfactor) draws a contour plot of the loadfactor matrix in the x-y plane. This function is based on the MATLAB® contour function. The x-coordinates of the vertices correspond to the column indices of loadfactor and the y-coordinates correspond to the row indices of loadfactor. The contour automatically chooses the contour levels.

altitudeEnvelopeContour(airspeed,altitude,loadfactor) draws a contour plot of the loadfactor matrix using vertices from the mesh that airspeed and altitude define.

Draw Contour Plots with Customizations

example

altitudeEnvelopeContour(___,levels) plots an altitude envelope contour specified by the desired levels levels.

altitudeEnvelopeContour(___,LineSpec) plots an altitude envelope contour specified by the desired line spec LineSpec.

altitudeEnvelopeContour(___,Name,Value) plots an altitude envelope contour specified by one or more Name,Value arguments.

altitudeEnvelopeContour(ax,___) draws an altitude contour plot onto the axes ax.

Return Matrix, Contour Object, and Boundary Line Object

example

[c,h,bline] = altitudeEnvelopeContour(___) returns contour matrix c, a contour object h, and a vector of boundaryline objects b. To label the plot, use the c and bs arguments as inputs to the clabel function when using the LabelSpacing property.

Tip

For more information on the contour matrix, see the Contour Properties property for contour objects.

Examples

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Plot an altitude envelope contour with default levels and boundaries.

[speed,alt,loadfactor] = peaks();
altitudeEnvelopeContour(speed,alt,loadfactor)

altitudeEnvelopeContour(speed,alt,loadfactor)

Plot an altitude envelope contour with 20 levels and default boundaries.

[speed,alt,loadfactor] = peaks();
altitudeEnvelopeContour(speed,alt,loadfactor,20)

altitudeEnvelopeContour with levels

Plot an altitude envelope contour with constant boundary lines, and turn off boundary line intersection clipping.

[speed,alt,loadfactor] = peaks();
altitudeEnvelopeContour(speed,alt,loadfactor,...
"MinimumSpeed",0,"MaximumAltitude",2,"ResolveBoundary","off")

altitudeEnvelopeContour with constant boundary

Plot an altitude envelope contour with custom boundary data. Return line objects and boundary line objects in c, h, and b.

x = linspace(-15,15);
y = linspace(-15,15);
[X,Y] = meshgrid(x,y);
Z = sin(X)+cos(Y);
t = linspace(2*pi,0);
boundaryX = 16*sin(t).^3;
boundaryY = 13*cos(t) - 5*cos(2*t) - 2*cos(3*t) - cos(4*t);
[c,h,b]=altitudeEnvelopeContour(X,Y,Z,...
"BoundaryXData",boundaryX,"BoundaryYData",boundaryY);

altitudeEnvelopeContour returns heart-shaped contour

Input Arguments

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Load Factor for each airspeed and altitude, specified as a numeric matrix typically in g's.

Data Types: double

Aircraft airspeed for each corresponding index in loadfactor, specified as a numeric vector or matrix.

Data Types: double

Aircraft altitude for each corresponding index in loadfactor, specified as a numeric vector or matrix.

Data Types: double

Levels for which to develop contour lines, specified as a scalar or vector.

  • If levels is a scalar, levels specifies the number of contour lines, and the contour levels are chosen automatically by contour.

  • If levels is a vector, levels specifies the number and levels of contour lines to plot.

Tip

To draw the contours at one height (k), specify levels as a two-element row vector [k k].

Example: [2 3]

Data Types: double

Line style, marker, and color, specified as a string or character vector containing symbols. The symbols can appear in any order. You do not need to specify all three characteristics (line style, marker, and color). For example, if you omit the line style and specify the marker, then the plot shows only the marker and no line.

Example: "--or" is a red dashed line with circle markers

Line StyleDescriptionResulting Line
"-"Solid line

Sample of solid line

"--"Dashed line

Sample of dashed line

":"Dotted line

Sample of dotted line

"-."Dash-dotted line

Sample of dash-dotted line, with alternating dashes and dots

MarkerDescriptionResulting Marker
"o"Circle

Sample of circle marker

"+"Plus sign

Sample of plus sign marker

"*"Asterisk

Sample of asterisk marker

"."Point

Sample of point marker

"x"Cross

Sample of cross marker

"_"Horizontal line

Sample of horizontal line marker

"|"Vertical line

Sample of vertical line marker

"square"Square

Sample of square marker

"diamond"Diamond

Sample of diamond line marker

"^"Upward-pointing triangle

Sample of upward-pointing triangle marker

"v"Downward-pointing triangle

Sample of downward-pointing triangle marker

">"Right-pointing triangle

Sample of right-pointing triangle marker

"<"Left-pointing triangle

Sample of left-pointing triangle marker

"pentagram"Pentagram

Sample of pentagram marker

"hexagram"Hexagram

Sample of hexagram marker

Color NameShort NameRGB TripletAppearance
"red""r"[1 0 0]

Sample of the color red

"green""g"[0 1 0]

Sample of the color green

"blue""b"[0 0 1]

Sample of the color blue

"cyan" "c"[0 1 1]

Sample of the color cyan

"magenta""m"[1 0 1]

Sample of the color magenta

"yellow""y"[1 1 0]

Sample of the color yellow

"black""k"[0 0 0]

Sample of the color black

"white""w"[1 1 1]

Sample of the color white

Valid axes, specified as a scalar handle. By default, this function plots to the current axes, obtainable with the gca function.

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: "MinimumSpeed",0

Note

The properties listed here are only a subset. For a full list, see Contour Properties.

Minimum altitude boundary, specified as a numeric scalar or n-by-2 matrix.

  • If MinimumAltitude is a scalar, MinimumAltitude specifies a horizontal line that intersects with the X limits of the axes or with the intersection of MinimumSpeed and MaximumSpeed.

  • If MinimumAltitude is an n-by-2 matrix, each row is an airspeed and altitude point of the boundary.

The function marks loadfactor values below MinimumAltitude as NaN.

Data Types: double

Maximum altitude boundary, specified as a numeric scalar or n-by-2 matrix.

  • If MaximumAltitude is a scalar, MaximumAltitude specifies a horizontal line that intersects with the X limits of the axes or with the intersection of MinimumSpeed and MaximumSpeed.

  • If MaximumAltitude is an n-by-2 matrix, each row is an airspeed and altitude point of the boundary.

The function marks loadfactor values above MaximumAltitude as NaN.

Data Types: double

Minimum speed boundary, specified as a numeric scalar or n-by-2 matrix.

  • If MinimumSpeed is a scalar, MinimumSpeed specifies a vertical line that intersects with the Y limits of the axes or with the intersection of MinimumAltitude and MaximumAltitude.

  • If MinimumSpeed is an n-by-2 matrix, each row is an airspeed and altitude point of the boundary.

The function marks loadfactor values behind MinimumSpeed as NaN.

Data Types: double

Maximum speed boundary, specified as a numeric scalar or n-by-2 matrix.

  • If MaximumSpeed is a scalar, MaximumSpeed specifies a vertical line that intersects with the Y limits of the axes or with the intersection of MinimumAltitude and MaximumAltitude.

  • If MaximumSpeed is an n-by-2 matrix, each row is an airspeed and altitude point of the boundary.

The function marks as NaN loadfactor values in front of MaximumSpeed.

Data Types: double

Boundary line X data, specified as a numeric vector.

Data Types: double

Boundary line Y data, specified as a numeric vector.

Data Types: double

Contour data display, specified as:

  • 'on' — Remove the contour data outside the specified boundary lines.

  • 'off' — Show all contour data and specified boundary lines.

Data Types: double | logical | string

Boundary line intersection and enclosure, specified as:

  • 'on' — Resolve boundary line segments to form a closed boundary around the line intersection points. Boundary data points outside the resolved boundary are removed. This method produces a well-formed boundary, but does not allow infinite limits or unconnected boundary lines.

  • 'off' — Do not resolve boundary line segments. This method leaves the boundary line data unmodified to allow infinite limits and unconnected boundary lines.

    Tip

    This method might produce a malformed boundary that affects the ClipContour behavior.

Data Types: double | logical | string

Output Arguments

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Contour, returned as a numeric matrix.

Contour graphics object, returned as a scalar.

One or more boundary line objects, returned as a scalar or a vector. These are unique identifiers, which you can use to query and modify properties of a specific chart line. For a list of properties, see Line Properties.

More About

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Load Factor

Typically calculated as lift/weight where:

  • lift — Lift of the aircraft.

  • weight — Weight of the aircraft.

Version History

Introduced in R2021b