package owl

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package owl
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Plot: high-level plotting functions.

The input to a plot function is supposed to be a row-based matrix/vector. The functions in this module are built atop of Plplot library.

Type definition
type handle
type color =
  1. | RED
  2. | GREEN
  3. | BLUE
type legend_position =
  1. | North
  2. | South
  3. | West
  4. | East
  5. | NorthWest
  6. | NorthEast
  7. | SouthWest
  8. | SouthEast
type axis =
  1. | X
  2. | Y
  3. | Z
  4. | XY
  5. | XZ
  6. | YZ
  7. | XYZ
type spec =
  1. | RGB of int * int * int
  2. | LineStyle of int
  3. | LineWidth of float
  4. | Marker of string
  5. | MarkerSize of float
  6. | Fill
  7. | FillPattern of int
  8. | Contour
  9. | Altitude of float
  10. | Azimuth of float
  11. | ZLine of axis
  12. | NoMagColor
  13. | Curtain
  14. | Faceted
  15. | Axis of axis
Config functions
val create : ?m:int -> ?n:int -> string -> handle
val subplot : handle -> int -> int -> unit
val output : handle -> unit
val set_output : handle -> string -> unit
val set_title : handle -> string -> unit
val set_xlabel : handle -> string -> unit
val set_ylabel : handle -> string -> unit
val set_zlabel : handle -> string -> unit
val set_xrange : handle -> float -> float -> unit
val set_yrange : handle -> float -> float -> unit
val set_zrange : handle -> float -> float -> unit
val set_xticklabels : handle -> (float * string) list -> unit
val set_yticklabels : handle -> (float * string) list -> unit
val set_zticklabels : handle -> (float * string) list -> unit
val set_foreground_color : handle -> int -> int -> int -> unit
val set_background_color : handle -> int -> int -> int -> unit
val set_font_size : handle -> float -> unit
val set_pen_size : handle -> float -> unit
val set_page_size : handle -> int -> int -> unit
val legend_on : handle -> ?position:legend_position -> string array -> unit
val legend_off : handle -> unit
Basic plot functions

Line style is an integer ranging from 1 to 8.

val plot : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

plot x y plots y as a function of x.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val plot_fun : ?h:handle -> ?spec:spec list -> (float -> float) -> float -> float -> unit

plot_fun f a b generates a line plot for function f : float -> float in the interval a, b.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val scatter : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

scatter x y generates a scatter plot of y as a function of x.

Parameters: RGB, Marker, MarkerSize.

val histogram : ?h:handle -> ?spec:spec list -> ?bin:int -> dsmat -> unit

histogram x generates a histogram of x with the number bin.

Parameters: RGB.

val ecdf : ?h:handle -> ?spec:spec list -> dsmat -> unit

ecdf x

Parameters: RGB, LineStyle, LineWidth.

val stairs : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

stairs x y

Parameters: RGB, LineStyle, LineWidth.

val stem : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

stem x generates a stem plot of y as a function of x.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val autocorr : ?h:handle -> ?spec:spec list -> dsmat -> unit

autocorr x generates an autocorrelation plot of x.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val text : ?h:handle -> ?spec:spec list -> float -> float -> ?dx:float -> ?dy:float -> string -> unit

text x y s draws a text string at (x,y). dx and dy indicate ...

Parameters: RGB.

val draw_line : ?h:handle -> ?spec:spec list -> float -> float -> float -> float -> unit

draw_line x0 y0 x1 y0 draws a straight line from (x0,y0) to (x1,y1).

Parameters: RGB, LineStyle, LineWidth.

val draw_rect : ?h:handle -> ?spec:spec list -> float -> float -> float -> float -> unit

draw_rect x0 y0 x1 y1 draws a rectangle with top-left point at (x0,y0) and bottom-right point at (x1,y1).

Parameters: RGB, LineStyle, FillPattern.

val draw_circle : ?h:handle -> ?spec:spec list -> float -> float -> float -> unit

draw_circle x y r draws a circle at point (x,y) of radius r.

Parameters: RGB, LineStyle, LineWidth, FillPattern.

val bar : ?h:handle -> ?spec:spec list -> dsmat -> unit

bar x draws a bar chart of x.

Parameters: RGB, LineStyle, FillPattern.

val area : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

area x y fills the area specified by x and y.

Parameters: RGB, LineStyle, FillPattern.

val draw_polygon : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> unit

area x y fills the polygon specified by x and y. Each point will be treated as connected to the next point except the last, which will be connected to the first point.

Parameters: RGB, LineStyle, FillPattern.

val error_bar : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> dsmat -> unit

error_bar x y generates a line plot of x and y with error bars.

Parameters: RGB, LineStyle, LineWidth.

val boxplot : ?h:handle -> ?spec:spec list -> dsmat -> unit

boxplot x generates a box plot of x.

Parameters: RGB.

val pie : ?h:handle -> ?spec:spec list -> dsmat -> unit

pie x generates a simple pie chart of x.

Parameters: RGB, Fill.

val loglog : ?h:handle -> ?spec:spec list -> ?x:dsmat -> dsmat -> unit

loglog ~x y plots all y versus x pairs with log-log scale. loglog y plots data in y versus their indices. If Axis X or Axis Y is specified in spec, plot logarithmic scales only for x-axis or y-axis respectively.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth, Axis.

val semilogx : ?h:handle -> ?spec:spec list -> ?x:dsmat -> dsmat -> unit

semilogx is similar to loglog. Plot data as logarithmic scales for the x-axis.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val semilogy : ?h:handle -> ?spec:spec list -> ?x:dsmat -> dsmat -> unit

semilogy is similar to loglog. Plot data as logarithmic scales for the y-axis.

Parameters: RGB, Marker, MarkerSize, LineStyle, LineWidth.

val spy : ?h:handle -> ?spec:spec list -> dsmat -> unit

spy x visualises the sparsity of the matrix x using scatter plot. The non-zero elements are plotted as dots, and zeros are ignored.

Parameters: RGB, Marker, MarkerSize.

3D plot functions
val plot3d : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> dsmat -> unit

TODO: plot3d is just an alias of surf function.

val surf : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> dsmat -> unit

surf x y z generates a surface plot defined by x, y, and z.

Parameters: Altitude, Azimuth, Contour, NoMagColor, Curtain.

Please refer to plotsurf3d functions in the PLplot library for more information.

val mesh : ?h:handle -> ?spec:spec list -> dsmat -> dsmat -> dsmat -> unit

mesh x y z generates a mesh plot defined by x, y, and z.

Parameters: RGB, Altitude, Azimuth, Contour, NoMagColor, ZLine, Curtain.

Please refer to plmesh and plmeshc functions in the PLplot library for more information.

val contour : ?h:handle -> dsmat -> dsmat -> dsmat -> unit

contour x y z generates a contour plot defined by x, y, and z.

val heatmap : ?h:handle -> dsmat -> dsmat -> dsmat -> unit

heatmap x y z generates a heatmap defined by x, y, and z.

Advanced statistical plot
val probplot : ?h:handle -> ?spec:spec list -> ?dist:(float -> float) -> ?noref:bool -> dsmat -> unit

probplot ~dist ~noref x creates a probability plot comparing the distribution of the data in x to the given distribution. The dist is set to standard normal distribution by default. When noref is set to true (default to be false), the reference line will not be shown.

Note that in our implementation of probplot, we choose a Matlab-like definition: for the i-th point on the figure, x-axis is the sorted input sample data x.(i), and y-axis is the inverseCDF (for different dist) of meadian (i - 0.5)/n, where n is the length of input data,

The y-axis is to be updated to corrsponding probability p = cdf(y) * 100%.

The same definition also applies to normplot and wblplot.

Parameters: RGB, Marker, MarkerSize.

val normplot : ?h:handle -> ?spec:spec list -> ?sigma:float -> dsmat -> unit

normalplot ~sigma x is probplot with normal distribution. User need to specify the sigma of distribution or the default value 1 will be used.

Parameters: RGB, Marker, MarkerSize.

val wblplot : ?h:handle -> ?spec:spec list -> ?lambda:float -> ?k:float -> dsmat -> unit

wblplot ~lambda ~k x is probplot with weibull distribution. Currently user need to specify the weibull distribution parameters lambda and k explicitly. By default, (lambda, k) = (1., 1.). wblplot applies log-scale on x-axis.

Parameters: RGB, Marker, MarkerSize.

val qqplot : ?h:handle -> ?spec:spec list -> ?pd:(float -> float) -> ?x:dsmat -> dsmat -> unit

qqplot ~pd ~x y displays a quantile-quantile plot of the quantiles of the sample data x versus the theoretical quantiles values from pd, which by default is standard normal distribution. If the second argument x is a vector, the empirical CDF of it is used as the distribtion of x-axis data, otherwise the qqplot is similar to probplot, showing the inverseCDF of meadian [(i - 0.5)/n] on x-axis.

If input vectors are not of the same length, users are explected to input the longer one as x, and the shorter one y.

Parameters: RGB, Marker, MarkerSize.

val image : ?h:handle -> dsmat -> unit

image mat display a m * n matrix as image. Each element in the matrix is of range 0 ~ 255.