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gr Reference¶

Output Functions¶

gr.polyline(x, y)[source]¶

Draw a polyline using the current line attributes, starting from the first data point and ending at the last data point.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates

The values for x and y are in world coordinates. The attributes that control the appearance of a polyline are linetype, linewidth and color index.

gr.polymarker(x, y)[source]¶

Draw marker symbols centered at the given data points.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates

The values for x and y are in world coordinates. The attributes that control the appearance of a polymarker are marker type, marker size scale factor and color index.

gr.text(x, y, string)[source]¶

Draw a text at position x, y using the current text attributes.

Parameters:

x :: The X coordinate of starting position of the text string
y :: The Y coordinate of starting position of the text string
string :: The text to be drawn

The values for x and y are in normalized device coordinates. The attributes that control the appearance of text are text font and precision, character expansion factor, character spacing, text color index, character height, character up vector, text path and text alignment.

gr.fillarea(x, y)[source]¶

Allows you to specify a polygonal shape of an area to be filled.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates

The attributes that control the appearance of fill areas are fill area interior style, fill area style index and fill area color index.

gr.cellarray(xmin, xmax, ymin, ymax, dimx, dimy, color)[source]¶

Display rasterlike images in a device-independent manner. The cell array function partitions a rectangle given by two corner points into DIMX X DIMY cells, each of them colored individually by the corresponding color index of the given cell array.

Parameters:

xmin, ymin :: Lower left point of the rectangle
xmax, ymax :: Upper right point of the rectangle
dimx, dimy :: X and Y dimension of the color index array
color :: Color index array

The values for xmin, xmax, ymin and ymax are in world coordinates.

gr.shadepoints(x, y, dims=(1200, 1200), xform=1)[source]¶

Display a point set as an aggregated and rasterized image using the current GR colormap.

Parameters:

x :: A pointer to the X coordinates
y :: A pointer to the Y coordinates
dims :: The size of the grid used for rasterization
xform :: The transformation type used for color mapping

The values for x and y are in world coordinates.

The available transformation types are:

XFORM_BOOLEAN	0	boolean
XFORM_LINEAR	1	linear
XFORM_LOG	2	logarithmic
XFORM_LOGLOG	3	double logarithmic
XFORM_CUBIC	4	cubic
XFORM_EQUALIZED	5	histogram equalized

gr.shadelines(x, y, dims=(1200, 1200), xform=1)[source]¶

Display a line set as an aggregated and rasterized image using the current GR colormap.

Parameters:

x :: A pointer to the X coordinates
y :: A pointer to the Y coordinates
dims :: The size of the grid used for rasterization
xform :: The transformation type used for color mapping

The values for x and y are in world coordinates. NaN values can be used to separate the point set into line segments.

The available transformation types are:

XFORM_BOOLEAN	0	boolean
XFORM_LINEAR	1	linear
XFORM_LOG	2	logarithmic
XFORM_LOGLOG	3	double logarithmic
XFORM_CUBIC	4	cubic
XFORM_EQUALIZED	5	histogram equalized

gr.spline(px, py, m, method)[source]¶

Generate a cubic spline-fit, starting from the first data point and ending at the last data point.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates
m :: The number of points in the polygon to be drawn (m > len(x))
method :: The smoothing method

The values for x and y are in world coordinates. The attributes that control the appearance of a spline-fit are linetype, linewidth and color index.

If method is > 0, then a generalized cross-validated smoothing spline is calculated. If method is 0, then an interpolating natural cubic spline is calculated. If method is < -1, then a cubic B-spline is calculated.

gr.textext(x, y, string)[source]¶

Draw a text at position x, y using the current text attributes. Strings can be defined to create basic mathematical expressions and Greek letters.

Parameters:

x :: The X coordinate of starting position of the text string
y :: The Y coordinate of starting position of the text string
string :: The text to be drawn

The values for X and Y are in normalized device coordinates. The attributes that control the appearance of text are text font and precision, character expansion factor, character spacing, text color index, character height, character up vector, text path and text alignment.

The character string is interpreted to be a simple mathematical formula. The following notations apply:

Subscripts and superscripts: These are indicated by carets (‘^’) and underscores (‘_’). If the sub/superscript contains more than one character, it must be enclosed in curly braces (‘{}’).

Fractions are typeset with A ‘/’ B, where A stands for the numerator and B for the denominator.

To include a Greek letter you must specify the corresponding keyword after a backslash (‘’) character. The text translator produces uppercase or lowercase Greek letters depending on the case of the keyword.

Letter	Keyword
Α α	alpha
Β β	beta
Γ γ	gamma
Δ δ	delta
Ε ε	epsilon
Ζ ζ	zeta
Η η	eta
Θ θ	theta
Ι ι	iota
Κ κ	kappa
Λ λ	lambda
Μ μ	mu
Ν ν	Nu / v
Ξ ξ	xi
Ο ο	omicron
Π π	pi
Ρ ρ	rho
Σ σ	sigma
Τ τ	tau
Υ υ	upsilon
Φ φ	phi
Χ χ	chi
Ψ ψ	psi
Ω ω	omega

Note: v is a replacement for nu which would conflict with n (newline)

For more sophisticated mathematical formulas, you should use the gr.mathtex function.

gr.inqtextext(x, y, string)[source]¶

gr.axes(x_tick, y_tick, x_org, y_org, major_x, major_y, tick_size)[source]¶

Draw X and Y coordinate axes with linearly and/or logarithmically spaced tick marks.

Parameters:

x_tick, y_tick :: The interval between minor tick marks on each axis.
x_org, y_org :: The world coordinates of the origin (point of intersection) of the X and Y axes.
major_x, major_y :: Unitless integer values specifying the number of minor tick intervals between major tick marks. Values of 0 or 1 imply no minor ticks. Negative values specify no labels will be drawn for the associated axis.
tick_size :: The length of minor tick marks specified in a normalized device coordinate unit. Major tick marks are twice as long as minor tick marks. A negative value reverses the tick marks on the axes from inward facing to outward facing (or vice versa).

Tick marks are positioned along each axis so that major tick marks fall on the axes origin (whether visible or not). Major tick marks are labeled with the corresponding data values. Axes are drawn according to the scale of the window. Axes and tick marks are drawn using solid lines; line color and width can be modified using the setlinetype and setlinewidth functions. Axes are drawn according to the linear or logarithmic transformation established by the setscale function.

gr.grid(x_tick, y_tick, x_org, y_org, major_x, major_y)[source]¶

Draw a linear and/or logarithmic grid.

Parameters:

x_tick, y_tick :: The length in world coordinates of the interval between minor grid lines.
x_org, y_org :: The world coordinates of the origin (point of intersection) of the grid.
major_x, major_y :: Unitless integer values specifying the number of minor grid lines between major grid lines. Values of 0 or 1 imply no grid lines.

Major grid lines correspond to the axes origin and major tick marks whether visible or not. Minor grid lines are drawn at points equal to minor tick marks. Major grid lines are drawn using black lines and minor grid lines are drawn using gray lines.

gr.verrorbars(px, py, e1, e2)[source]¶

Draw a standard vertical error bar graph.

Parameters:

px :: A list of length N containing the X coordinates
py :: A list of length N containing the Y coordinates
e1 :: The absolute values of the lower error bar data
e2 :: The absolute values of the upper error bar data

gr.herrorbars(px, py, e1, e2)[source]¶

Draw a standard horizontal error bar graph.

Parameters:

px :: A list of length N containing the X coordinates
py :: A list of length N containing the Y coordinates
e1 :: The absolute values of the lower error bar data
e2 :: The absolute values of the upper error bar data

gr.polyline3d(px, py, pz)[source]¶

Draw a 3D curve using the current line attributes, starting from the first data point and ending at the last data point.

Parameters:

x :: A list of length N containing the X coordinates
y :: A list of length N containing the Y coordinates
z :: A list of length N containing the Z coordinates

The values for x, y and z are in world coordinates. The attributes that control the appearance of a polyline are linetype, linewidth and color index.

gr.axes3d(x_tick, y_tick, z_tick, x_org, y_org, z_org, major_x, major_y, major_z, tick_size)[source]¶

Draw X, Y and Z coordinate axes with linearly and/or logarithmically spaced tick marks.

Parameters:

x_tick, y_tick, z_tick :: The interval between minor tick marks on each axis.
x_org, y_org, z_org :: The world coordinates of the origin (point of intersection) of the X and Y axes.
major_x, major_y, major_z :: Unitless integer values specifying the number of minor tick intervals between major tick marks. Values of 0 or 1 imply no minor ticks. Negative values specify no labels will be drawn for the associated axis.
tick_size :: The length of minor tick marks specified in a normalized device coordinate unit. Major tick marks are twice as long as minor tick marks. A negative value reverses the tick marks on the axes from inward facing to outward facing (or vice versa).

gr.titles3d(x_title, y_title, z_title)[source]¶

Display axis titles just outside of their respective axes.

Parameters:

x_title, y_title, z_title :: The text to be displayed on each axis

gr.volume(data, algorithm=0, dmin=-1, dmax=-1)[source]¶

Draw volume data using the given algorithm and apply the current GR colormap. Returns the minimum and maximum data value that were used when applying the colormap.

Parameters:

data :: 3D numpy array containing the intensities for each point
algorithm :: The algorithm used to reduce the volume data
dmin :: The minimum data value when applying the colormap. If it is negative, the actual occurring minimum is used.
dmax :: The maximum data value when applying the colormap. If it is negative, the actual occurring maximum is used.

Available algorithms are:

VOLUME_EMISSION	0	emission model
VOLUME_ABSORPTION	1	absorption model
VOLUME_MIP	2	maximum intensity projection

gr.surface(px, py, pz, option)[source]¶

Draw a three-dimensional surface plot for the given data points.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates
z :: A list of length len(x) * len(y) or an appropriately dimensioned array containing the Z coordinates
option :: Surface display option (see table below)

x and y define a grid. z is a singly dimensioned array containing at least nx * ny data points. Z describes the surface height at each point on the grid. Data is ordered as shown in the following table:

LINES	0	Use X Y polylines to denote the surface
MESH	1	Use a wire grid to denote the surface
FILLED_MESH	2	Applies an opaque grid to the surface
Z_SHADED_MESH	3	Applies Z-value shading to the surface
COLORED_MESH	4	Applies a colored grid to the surface
CELL_ARRAY	5	Applies a grid of individually-colored cells to the surface
SHADED_MESH	6	Applies light source shading to the 3-D surface

gr.contour(px, py, h, pz, major_h)[source]¶

Draw contours of a three-dimensional data set whose values are specified over a rectangular mesh. Contour lines may optionally be labeled.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates
h :: A list containing the Z coordinate for the height values
z :: A list of length len(x) * len(y) or an appropriately dimensioned array containing the Z coordinates
major_h :: Directs GR to label contour lines. For example, a value of 3 would label every third line. A value of 1 will label every line. A value of 0 produces no labels. To produce colored contour lines, add an offset of 1000 to major_h.

gr.drawrect(xmin, xmax, ymin, ymax)[source]¶

Draw a rectangle using the current line attributes.

Parameters:

xmin :: Lower left edge of the rectangle
xmax :: Lower right edge of the rectangle
ymin :: Upper left edge of the rectangle
ymax :: Upper right edge of the rectangle

gr.fillrect(xmin, xmax, ymin, ymax)[source]¶

Draw a filled rectangle using the current fill attributes.

Parameters:

xmin :: Lower left edge of the rectangle
xmax :: Lower right edge of the rectangle
ymin :: Upper left edge of the rectangle
ymax :: Upper right edge of the rectangle

gr.drawarc(xmin, xmax, ymin, ymax, a1, a2)[source]¶

Draw a circular or elliptical arc covering the specified rectangle.

Parameters:

xmin :: Lower left edge of the rectangle
xmax :: Lower right edge of the rectangle
ymin :: Upper left edge of the rectangle
ymax :: Upper right edge of the rectangle
a1 :: The start angle
a2 :: The end angle

The resulting arc begins at a1 and ends at a2 degrees. Angles are interpreted such that 0 degrees is at the 3 o’clock position. The center of the arc is the center of the given rectangle.

gr.fillarc(xmin, xmax, ymin, ymax, a1, a2)[source]¶

Fill a circular or elliptical arc covering the specified rectangle.

Parameters:

xmin :: Lower left edge of the rectangle
xmax :: Lower right edge of the rectangle
ymin :: Upper left edge of the rectangle
ymax :: Upper right edge of the rectangle
a1 :: The start angle
a2 :: The end angle

The resulting arc begins at a1 and ends at a2 degrees. Angles are interpreted such that 0 degrees is at the 3 o’clock position. The center of the arc is the center of the given rectangle.

gr.drawarrow(x1, y1, x2, y2)[source]¶

Draw an arrow between two points.

Parameters:

x1, y1 :: Starting point of the arrow (tail)
x2, y2 :: Head of the arrow

Different arrow styles (angles between arrow tail and wing, optionally filled heads, double headed arrows) are available and can be set with the setarrowstyle function.

gr.drawimage(xmin, xmax, ymin, ymax, width, height, data, model=0)[source]¶

Draw an image into a given rectangular area.

Parameters:

xmin, ymin :: First corner point of the rectangle
xmax, ymax :: Second corner point of the rectangle
width, height :: The width and the height of the image
data :: An array of color values dimensioned width by height
model :: Color model (default=0)

The available color models are:

MODEL_RGB	0	AABBGGRR
MODEL_HSV	1	AAVVSSHH

The points (xmin, ymin) and (xmax, ymax) are world coordinates defining diagonally opposite corner points of a rectangle. This rectangle is divided into width by height cells. The two-dimensional array data specifies colors for each cell.

gr.mathtex(x, y, string)[source]¶

Generate a character string starting at the given location. Strings can be defined to create mathematical symbols and Greek letters using LaTeX syntax.

Parameters:

x, y :: Position of the text string specified in world coordinates
string :: The text string to be drawn

gr.path(x, y, codes)[source]¶

Draw paths using the given vertices and path codes.

Parameters:

x :: A list containing the X coordinates
y :: A list containing the Y coordinates
codes :: A list containing the path codes

The values for x and y are in world coordinates. The codes describe several path primitives that can be used to create compound paths.

The following path codes are recognized:

Code	Description	x	y
M, m	move	x	y
L, l	line	x	y
Q, q	quadratic Bezier	x1, x2	y1, y2
C, c	cubic Bezier	x1, x2, x3	y1, y2, y3
A, a	arc	rx, a1, reserved	ry, a2, reserved
Z	close path
S	stroke
s	close path and stroke
f	close path and fill
F	close path, fill and stroke

Move: M, m
Moves the current position to (x, y). The new position is either absolute (M) or relative to the current position (m). The initial position of gr.path() is (0, 0).

Example:
>>> gr.path([0.5, -0.1], [0.2, 0.1], "Mm")
The first move command in this example moves the current position to the absolute coordinates (0.5, 0.2). The second move to performs a movement by (-0.1, 0.1) relative to the current position resulting in the point (0.4, 0.3).
Line: L, l
Draws a line from the current position to the given position (x, y). The end point of the line is either absolute (L) or relative to the current position (l). The current position is set to the end point of the line.

Example:
>>> gr.path([0.1, 0.5, 0.0], [0.1, 0.1, 0.2], "MLlS")
The first line to command draws a straight line from the current position (0.1, 0.1) to the absolute position (0.5, 0.1) resulting in a horizontal line. The second line to command draws a vertical line relative to the current position resulting in the end point (0.5, 0.3).
Quadratic Bezier curve: Q, q
Draws a quadratic bezier curve from the current position to the end point (x2, y2) using (x1, y1) as the control point. Both points are either absolute (Q) or relative to the current position (q). The current position is set to the end point of the bezier curve.

Example:
>>> gr.path([0.1, 0.3, 0.5, 0.2, 0.4], [0.1, 0.2, 0.1, 0.1, 0.0], "MQqS")
This example will generate two bezier curves whose start and end points are each located at y=0.1. As the control points are horizontally in the middle of each bezier curve with a higher y value both curves are symmetrical and bend slightly upwards in the middle. The current position is set to (0.9, 0.1) at the end.
Cubic Bezier curve: C, c
Draws a cubic bezier curve from the current position to the end point (x3, y3) using (x1, y1) and (x2, y2) as the control points. All three points are either absolute (C) or relative to the current position (c). The current position is set to the end point of the bezier curve.

Example:
>>> gr.path(
...     [0.1, 0.2, 0.3, 0.4, 0.1, 0.2, 0.3],
...     [0.1, 0.2, 0.0, 0.1, 0.1, -0.1, 0.0],
...     "MCcS"
... )
This example will generate two bezier curves whose start and end points are each located at y=0.1. As the control points are equally spaced along the x-axis and the first is above and the second is below the start and end points this creates a wave-like shape for both bezier curves. The current position is set to (0.8, 0.1) at the end.
Ellipctical arc: A, a
Draws an elliptical arc starting at the current position. The major axis of the ellipse is aligned with the x-axis and the minor axis is aligned with the y-axis of the plot. rx and ry are the ellipses radii along the major and minor axis. a1 and a2 define the start and end angle of the arc in radians. The current position is set to the end point of the arc. If a2 is greater than a1 the arc is drawn counter-clockwise, otherwise it is drawn clockwise. The a and A commands draw the same arc. The third coordinates of the x and y array are ignored and reserved for future use.

Examples:
>>> gr.path([0.1, 0.2, -3.14159 / 2, 0.0], [0.1, 0.4, 3.14159 / 2, 0.0], "MAS")
This example draws an arc starting at (0.1, 0.1). As the start angle -pi/2 is smaller than the end angle pi/2 the arc is drawn counter-clockwise. In this case the right half of an ellipse with an x radius of 0.2 and a y radius of 0.4 is shown. Therefore the current position is set to (0.1, 0.9) at the end.
>>> gr.path([0.1, 0.2, 3.14159 / 2, 0.0], [0.9, 0.4, -3.14159 / 2, 0.0], "MAS")
This examples draws the same arc as the previous one. The only difference is that the starting point is now at (0.1, 0.9) and the start angle pi/2 is greater than the end angle -pi/2 so that the ellipse arc is drawn clockwise. Therefore the current position is set to (0.1, 0.1) at the end.
Close path: Z

Closes the current path by connecting the current position to the target position of the last move command (m or M) with a straight line. If no move to was performed in this path it connects the current position to (0, 0). When the path is stroked this line will also be drawn.

Stroke path: S, s

Strokes the path with the current border width and border color (set with gr.setborderwidth() and gr.setbordercolorind()). In case of s the path is closed beforehand, which is equivalent to ZS.

Fill path: F, f

Fills the current path using the even-odd-rule using the current fill color. Filling a path implicitly closes the path. The fill color can be set using gr.setfillcolorind(). In case of F the path is also stroked using the current border width and color afterwards.

This function requires GR runtime version 0.45 or higher.

Attribute Functions¶

gr.setlinetype(style)[source]¶

Specify the line style for polylines.

Parameters:

style :: The polyline line style

The available line types are:

LINETYPE_SOLID	1	Solid line
LINETYPE_DASHED	2	Dashed line
LINETYPE_DOTTED	3	Dotted line
LINETYPE_DASHED_DOTTED	4	Dashed-dotted line
LINETYPE_DASH_2_DOT	-1	Sequence of one dash followed by two dots
LINETYPE_DASH_3_DOT	-2	Sequence of one dash followed by three dots
LINETYPE_LONG_DASH	-3	Sequence of long dashes
LINETYPE_LONG_SHORT_DASH	-4	Sequence of a long dash followed by a short dash
LINETYPE_SPACED_DASH	-5	Sequence of dashes double spaced
LINETYPE_SPACED_DOT	-6	Sequence of dots double spaced
LINETYPE_DOUBLE_DOT	-7	Sequence of pairs of dots
LINETYPE_TRIPLE_DOT	-8	Sequence of groups of three dots

gr.setlinewidth(width)[source]¶

Define the line width of subsequent polyline output primitives.

Parameters:

width :: The polyline line width scale factor

The line width is calculated as the nominal line width generated on the workstation multiplied by the line width scale factor. This value is mapped by the workstation to the nearest available line width. The default line width is 1.0, or 1 times the line width generated on the graphics device.

gr.setlinecolorind(color)[source]¶

Define the color of subsequent polyline output primitives.

Parameters:

color :: The polyline color index (COLOR < 1256)

gr.setmarkertype(style)[source]¶

Specifiy the marker type for polymarkers.

Parameters:

style :: The polymarker marker type

The available marker types are:

MARKERTYPE_DOT	1	Smallest displayable dot
MARKERTYPE_PLUS	2	Plus sign
MARKERTYPE_ASTERISK	3	Asterisk
MARKERTYPE_CIRCLE	4	Hollow circle
MARKERTYPE_DIAGONAL_CROSS	5	Diagonal cross
MARKERTYPE_SOLID_CIRCLE	-1	Filled circle
MARKERTYPE_TRIANGLE_UP	-2	Hollow triangle pointing upward
MARKERTYPE_SOLID_TRI_UP	-3	Filled triangle pointing upward
MARKERTYPE_TRIANGLE_DOWN	-4	Hollow triangle pointing downward
MARKERTYPE_SOLID_TRI_DOWN	-5	Filled triangle pointing downward
MARKERTYPE_SQUARE	-6	Hollow square
MARKERTYPE_SOLID_SQUARE	-7	Filled square
MARKERTYPE_BOWTIE	-8	Hollow bowtie
MARKERTYPE_SOLID_BOWTIE	-9	Filled bowtie
MARKERTYPE_HGLASS	-10	Hollow hourglass
MARKERTYPE_SOLID_HGLASS	-11	Filled hourglass
MARKERTYPE_DIAMOND	-12	Hollow diamond
MARKERTYPE_SOLID_DIAMOND	-13	Filled Diamond
MARKERTYPE_STAR	-14	Hollow star
MARKERTYPE_SOLID_STAR	-15	Filled Star
MARKERTYPE_TRI_UP_DOWN	-16	Hollow triangles pointing up and down overlaid
MARKERTYPE_SOLID_TRI_RIGHT	-17	Filled triangle point right
MARKERTYPE_SOLID_TRI_LEFT	-18	Filled triangle pointing left
MARKERTYPE_HOLLOW PLUS	-19	Hollow plus sign
MARKERTYPE_SOLID PLUS	-20	Solid plus sign
MARKERTYPE_PENTAGON	-21	Pentagon
MARKERTYPE_HEXAGON	-22	Hexagon
MARKERTYPE_HEPTAGON	-23	Heptagon
MARKERTYPE_OCTAGON	-24	Octagon
MARKERTYPE_STAR_4	-25	4-pointed star
MARKERTYPE_STAR_5	-26	5-pointed star (pentagram)
MARKERTYPE_STAR_6	-27	6-pointed star (hexagram)
MARKERTYPE_STAR_7	-28	7-pointed star (heptagram)
MARKERTYPE_STAR_8	-29	8-pointed star (octagram)
MARKERTYPE_VLINE	-30	verical line
MARKERTYPE_HLINE	-31	horizontal line
MARKERTYPE_OMARK	-32	o-mark

Polymarkers appear centered over their specified coordinates.

gr.inqmarkertype()[source]¶

gr.setmarkersize(size)[source]¶

Specify the marker size for polymarkers.

Parameters:

size :: Scale factor applied to the nominal marker size

The polymarker size is calculated as the nominal size generated on the graphics device multiplied by the marker size scale factor.

gr.inqmarkersize()[source]¶

Inquire the marker size for polymarkers.

This function requires GR runtime version 0.41.5.post47 or higher.

gr.setmarkercolorind(color)[source]¶

Define the color of subsequent polymarker output primitives.

Parameters:

color :: The polymarker color index (COLOR < 1256)

gr.inqmarkercolorind()[source]¶

gr.settextfontprec(font, precision)[source]¶

Specify the text font and precision for subsequent text output primitives.

Parameters:

font :: Text font (see tables below)
precision :: Text precision (see table below)

The available text fonts are:

FONT_TIMES_ROMAN	101
FONT_TIMES_ITALIC	102
FONT_TIMES_BOLD	103
FONT_TIMES_BOLDITALIC	104
FONT_HELVETICA	105
FONT_HELVETICA_OBLIQUE	106
FONT_HELVETICA_BOLD	107
FONT_HELVETICA_BOLDOBLIQUE	108
FONT_COURIER	109
FONT_COURIER_OBLIQUE	110
FONT_COURIER_BOLD	111
FONT_COURIER_BOLDOBLIQUE	112
FONT_SYMBOL	113
FONT_BOOKMAN_LIGHT	114
FONT_BOOKMAN_LIGHTITALIC	115
FONT_BOOKMAN_DEMI	116
FONT_BOOKMAN_DEMIITALIC	117
FONT_NEWCENTURYSCHLBK_ROMAN	118
FONT_NEWCENTURYSCHLBK_ITALIC	119
FONT_NEWCENTURYSCHLBK_BOLD	120
FONT_NEWCENTURYSCHLBK_BOLDITALIC	121
FONT_AVANTGARDE_BOOK	122
FONT_AVANTGARDE_BOOKOBLIQUE	123
FONT_AVANTGARDE_DEMI	124
FONT_AVANTGARDE_DEMIOBLIQUE	125
FONT_PALATINO_ROMAN	126
FONT_PALATINO_ITALIC	127
FONT_PALATINO_BOLD	128
FONT_PALATINO_BOLDITALIC	129
FONT_ZAPFCHANCERY_MEDIUMITALIC	130
FONT_ZAPFDINGBATS	131
FONT_COMPUTERMODERN	232
FONT_DEJAVUSANS	233

The available text precisions are:

TEXT_PRECISION_STRING	0	String precision (higher quality)
TEXT_PRECISION_CHAR	1	Character precision (medium quality)
TEXT_PRECISION_STROKE	2	Stroke precision (lower quality)
TEXT_PRECISION_OUTLINE	3	Outline precision (highest quality)

The appearance of a font depends on the text precision value specified. STRING, CHARACTER or STROKE precision allows for a greater or lesser realization of the text primitives, for efficiency. STRING is the default precision for GR and produces the high quality output using either native font rendering or FreeType. OUTLINE uses the GR path rendering functions to draw individual glyphs and produces the highest quality output.

gr.setcharexpan(factor)[source]¶

Set the current character expansion factor (width to height ratio).

Parameters:

factor :: Text expansion factor applied to the nominal text width-to-height ratio

setcharexpan defines the width of subsequent text output primitives. The expansion factor alters the width of the generated characters, but not their height. The default text expansion factor is 1, or one times the normal width-to-height ratio of the text.

gr.settextcolorind(color)[source]¶

Sets the current text color index.

Parameters:

color :: The text color index (COLOR < 1256)

settextcolorind defines the color of subsequent text output primitives. GR uses the default foreground color (black=1) for the default text color index.

gr.setcharheight(height)[source]¶

Set the current character height.

Parameters:

height :: Text height value

setcharheight defines the height of subsequent text output primitives. Text height is defined as a percentage of the default window. GR uses the default text height of 0.027 (2.7% of the height of the default window).

gr.setcharup(ux, uy)[source]¶

Set the current character text angle up vector.

Parameters:

ux, uy :: Text up vector

setcharup defines the vertical rotation of subsequent text output primitives. The text up vector is initially set to (0, 1), horizontal to the baseline.

gr.settextpath(path)[source]¶

Define the current direction in which subsequent text will be drawn.

Parameters:

path :: Text path (see table below)

TEXT_PATH_RIGHT	0	left-to-right
TEXT_PATH_LEFT	1	right-to-left
TEXT_PATH_UP	2	downside-up
TEXT_PATH_DOWN	3	upside-down

gr.settextalign(horizontal, vertical)[source]¶

Set the current horizontal and vertical alignment for text.

Parameters:

horizontal :: Horizontal text alignment (see the table below)
vertical :: Vertical text alignment (see the table below)

settextalign specifies how the characters in a text primitive will be aligned in horizontal and vertical space. The default text alignment indicates horizontal left alignment and vertical baseline alignment.

TEXT_HALIGN_NORMAL	0
TEXT_HALIGN_LEFT	1	Left justify
TEXT_HALIGN_CENTER	2	Center justify
TEXT_HALIGN_RIGHT	3	Right justify

TEXT_VALIGN_NORMAL	0
TEXT_VALIGN_TOP	1	Align with the top of the characters
TEXT_VALIGN_CAP	2	Aligned with the cap of the characters
TEXT_VALIGN_HALF	3	Aligned with the half line of the characters
TEXT_VALIGN_BASE	4	Aligned with the base line of the characters
TEXT_VALIGN_BOTTOM	5	Aligned with the bottom line of the characters

gr.setfillintstyle(style)[source]¶

Set the fill area interior style to be used for fill areas.

Parameters:

style :: The style of fill to be used

setfillintstyle defines the interior style for subsequent fill area output primitives. The default interior style is HOLLOW.

HOLLOW	0	No filling. Just draw the bounding polyline
SOLID	1	Fill the interior of the polygon using the fill color index
PATTERN	2	Fill the interior of the polygon using the style index as a pattern index
HATCH	3	Fill the interior of the polygon using the style index as a cross-hatched style

gr.setfillstyle(index)[source]¶

Sets the fill style to be used for subsequent fill areas.

Parameters:

index :: The fill style index to be used

setfillstyle specifies an index when PATTERN fill or HATCH fill is requested by the setfillintstyle function. If the interior style is set to PATTERN, the fill style index points to a device-independent pattern table. If interior style is set to HATCH the fill style index indicates different hatch styles. If HOLLOW or SOLID is specified for the interior style, the fill style index is unused.

gr.setfillcolorind(color)[source]¶

Sets the current fill area color index.

Parameters:

color :: The fill area color index (COLOR < 1256)

setfillcolorind defines the color of subsequent fill area output primitives. GR uses the default foreground color (black=1) for the default fill area color index.

gr.setcolorrep(index, red, green, blue)[source]¶

setcolorrep allows to redefine an existing color index representation by specifying an RGB color triplet.

Parameters:

index :: Color index in the range 0 to 1256
red :: Red intensity in the range 0.0 to 1.0
green :: Green intensity in the range 0.0 to 1.0
blue:: Blue intensity in the range 0.0 to 1.0

gr.setcolormap(index)[source]¶

Set the current GR colormap.

Parameters:

index :: The colormap index, e.g. one of the gr.COLORMAP_* constants

For a list of built-in colormaps, see https://gr-framework.org/colormaps.html.

gr.setcolormapfromrgb(colors, positions=None)[source]¶

Define a linear interpolated colormap by a list of RGB colors.

Parameters:

colors :: A list of RGB tuples containing the normalized color intensities
positions :: An optional list of length len(colors) containing the normalized positions where the corresponding colors are applied. The first element must be 0.0, the last element 1.0.

If no positions are given the colors are evenly distributed in the linear interpolated colormap. Otherwise the values of positions define the particular position of the color in the colormap.

gr.setarrowstyle(style)[source]¶

Set the arrow style to be used for subsequent arrow commands.

Parameters:

style :: The arrow style to be used

setarrowstyle defines the arrow style for subsequent arrow primitives. The default arrow style is 1.

1	simple, single-ended
2	simple, single-ended, acute head
3	hollow, single-ended
4	filled, single-ended
5	triangle, single-ended
6	filled triangle, single-ended
7	kite, single-ended
8	filled kite, single-ended
9	simple, double-ended
10	simple, double-ended, acute head
11	hollow, double-ended
12	filled, double-ended
13	triangle, double-ended
14	filled triangle, double-ended
15	kite, double-ended
16	filled kite, double-ended
17	double line, single-ended
18	double line, double-ended

gr.setshadow(offsetx, offsety, blur)[source]¶

setshadow allows drawing of shadows, realized by images painted underneath, and offset from, graphics objects such that the shadow mimics the effect of a light source cast on the graphics objects.

Parameters:

offsetx :: An x-offset, which specifies how far in the horizontal direction the shadow is offset from the object
offsety :: A y-offset, which specifies how far in the vertical direction the shadow is offset from the object
blur :: A blur value, which specifies whether the object has a hard or a diffuse edge

gr.settransparency(alpha)[source]¶

Set the value of the alpha component associated with GR colors.

Parameters:

alpha :: An alpha value (0.0 - 1.0)

gr.setresamplemethod(resample_method)[source]¶

Set the resample method used for gr.drawimage().

Parameters:: resample_method – the new resample method

The available options are:

RESAMPLE_DEFAULT	0x00000000	default
RESAMPLE_NEAREST	0x01010101	nearest neighbour
RESAMPLE_LINEAR	0x02020202	linear
RESAMPLE_LANCZOS	0x03030303	Lanczos

Alternatively, combinations of these methods can be selected for horizontal or vertical upsampling or downsampling:

UPSAMPLE_VERTICAL_DEFAULT	0x00000000	default for vertical upsampling
UPSAMPLE_HORIZONTAL_DEFAULT	0x00000000	default for horizontal upsampling
DOWNSAMPLE_VERTICAL_DEFAULT	0x00000000	default for vertical downsampling
DOWNSAMPLE_HORIZONTAL_DEFAULT	0x00000000	default for horizontal downsampling
UPSAMPLE_VERTICAL_NEAREST	0x00000001	nearest neighbor for vertical upsampling
UPSAMPLE_HORIZONTAL_NEAREST	0x00000100	nearest neighbor for horizontal upsampling
DOWNSAMPLE_VERTICAL_NEAREST	0x00010000	nearest neighbor for vertical downsampling
DOWNSAMPLE_HORIZONTAL_NEAREST	0x01000000	nearest neighbor for horizontal downsampling
UPSAMPLE_VERTICAL_LINEAR	0x00000002	linear for vertical upsampling
UPSAMPLE_HORIZONTAL_LINEAR	0x00000200	linear for horizontal upsampling
DOWNSAMPLE_VERTICAL_LINEAR	0x00020000	linear for vertical downsampling
DOWNSAMPLE_HORIZONTAL_LINEAR	0x02000000	linear for horizontal downsampling
UPSAMPLE_VERTICAL_LANCZOS	0x00000003	lanczos for vertical upsampling
UPSAMPLE_HORIZONTAL_LANCZOS	0x00000300	lanczos for horizontal upsampling
DOWNSAMPLE_VERTICAL_LANCZOS	0x00030000	lanczos for vertical downsampling
DOWNSAMPLE_HORIZONTAL_LANCZOS	0x03000000	lanczos for horizontal downsampling

This function requires GR runtime version 0.41.5.post43 or higher.

gr.inqresamplemethod()[source]¶

Inquire the resample method used for gr.drawimage().

Returns:: the current resample method

This function requires GR runtime version 0.41.5.post43 or higher.

gr.setbordercolorind(color)[source]¶

Defines the color of subsequent path borders.

Parameters:

color :: The border color index (COLOR < 1256)

This function requires GR runtime version 0.45 or higher.

gr.inqbordercolorind()[source]¶

Returns the color index of path borders.

This function requires GR runtime version 0.45 or higher.

gr.setborderwidth(width)[source]¶

Defines the width of subsequent path borders.

Parameters:

width :: The border width

This function requires GR runtime version 0.45 or higher.

gr.inqborderwidth()[source]¶

Returns the width of path borders.

This function requires GR runtime version 0.45 or higher.

Transformation Functions¶

gr.setscale(options)[source]¶

setscale sets the type of transformation to be used for subsequent GR output primitives.

Parameters:

options :: Scale specification (see Table below)

OPTION_X_LOG	Logarithmic X-axis
OPTION_Y_LOG	Logarithmic Y-axis
OPTION_Z_LOG	Logarithmic Z-axis
OPTION_FLIP_X	Flip X-axis
OPTION_FLIP_Y	Flip Y-axis
OPTION_FLIP_Z	Flip Z-axis

setscale defines the current transformation according to the given scale specification which may be or’ed together using any of the above options. GR uses these options for all subsequent output primitives until another value is provided. The scale options are used to transform points from an abstract logarithmic or semi-logarithmic coordinate system, which may be flipped along each axis, into the world coordinate system.

Note: When applying a logarithmic transformation to a specific axis, the system assumes that the axes limits are greater than zero.

gr.inqscale()[source]¶

gr.setwindow(xmin, xmax, ymin, ymax)[source]¶

setwindow establishes a window, or rectangular subspace, of world coordinates to be plotted. If you desire log scaling or mirror-imaging of axes, use the SETSCALE function.

Parameters:

xmin :: The left horizontal coordinate of the window (xmin < xmax).
xmax :: The right horizontal coordinate of the window.
ymin :: The bottom vertical coordinate of the window (ymin < ymax).
ymax :: The top vertical coordinate of the window.

setwindow defines the rectangular portion of the World Coordinate space (WC) to be associated with the specified normalization transformation. The WC window and the Normalized Device Coordinates (NDC) viewport define the normalization transformation through which all output primitives are mapped. The WC window is mapped onto the rectangular NDC viewport which is, in turn, mapped onto the display surface of the open and active workstation, in device coordinates. By default, GR uses the range [0,1] x [0,1], in world coordinates, as the normalization transformation window.

gr.inqwindow()[source]¶

gr.setviewport(xmin, xmax, ymin, ymax)[source]¶

setviewport establishes a rectangular subspace of normalized device coordinates.

Parameters:

xmin :: The left horizontal coordinate of the viewport.
xmax :: The right horizontal coordinate of the viewport (0 <= xmin < xmax <= 1).
ymin :: The bottom vertical coordinate of the viewport.
ymax :: The top vertical coordinate of the viewport (0 <= ymin < ymax <= 1).

setviewport defines the rectangular portion of the Normalized Device Coordinate (NDC) space to be associated with the specified normalization transformation. The NDC viewport and World Coordinate (WC) window define the normalization transformation through which all output primitives pass. The WC window is mapped onto the rectangular NDC viewport which is, in turn, mapped onto the display surface of the open and active workstation, in device coordinates.

gr.selntran(transform)[source]¶

selntran selects a predefined transformation from world coordinates to normalized device coordinates.

Parameters:

transform :: A normalization transformation number.

0	Selects the identity transformation in which both the window and viewport have the range of 0 to 1
>= 1	Selects a normalization transformation as defined by setwindow and setviewport

gr.setclip(indicator)[source]¶

Set the clipping indicator.

Parameters:

indicator :: An indicator specifying whether clipping is on or off.

0	Clipping is off. Data outside of the window will be drawn.
1	Clipping is on. Data outside of the window will not be drawn.

setclip enables or disables clipping of the image drawn in the current window. Clipping is defined as the removal of those portions of the graph that lie outside of the defined viewport. If clipping is on, GR does not draw generated output primitives past the viewport boundaries. If clipping is off, primitives may exceed the viewport boundaries, and they will be drawn to the edge of the workstation window. By default, clipping is on.

gr.setwswindow(xmin, xmax, ymin, ymax)[source]¶

Set the area of the NDC viewport that is to be drawn in the workstation window.

Parameters:

xmin :: The left horizontal coordinate of the workstation window.
xmax :: The right horizontal coordinate of the workstation window (0 <= xmin < xmax <= 1).
ymin :: The bottom vertical coordinate of the workstation window.
ymax :: The top vertical coordinate of the workstation window (0 <= ymin < ymax <= 1).

setwswindow defines the rectangular area of the Normalized Device Coordinate space to be output to the device. By default, the workstation transformation will map the range [0,1] x [0,1] in NDC onto the largest square on the workstation’s display surface. The aspect ratio of the workstation window is maintained at 1 to 1.

gr.setwsviewport(xmin, xmax, ymin, ymax)[source]¶

Define the size of the workstation graphics window in meters.

Parameters:

xmin :: The left horizontal coordinate of the workstation viewport.
xmax :: The right horizontal coordinate of the workstation viewport.
ymin :: The bottom vertical coordinate of the workstation viewport.
ymax :: The top vertical coordinate of the workstation viewport.

setwsviewport places a workstation window on the display of the specified size in meters. This command allows the workstation window to be accurately sized for a display or hardcopy device, and is often useful for sizing graphs for desktop publishing applications.

gr.setspace(zmin, zmax, rotation, tilt)[source]¶

Set the abstract Z-space used for mapping three-dimensional output primitives into the current world coordinate space.

Parameters:

zmin :: Minimum value for the Z-axis.
zmax :: Maximum value for the Z-axis.
rotation :: Angle for the rotation of the X axis, in degrees.
tilt :: Viewing angle of the Z axis in degrees.

setspace establishes the limits of an abstract Z-axis and defines the angles for rotation and for the viewing angle (tilt) of a simulated three-dimensional graph, used for mapping corresponding output primitives into the current window. These settings are used for all subsequent three-dimensional output primitives until other values are specified. Angles of rotation and viewing angle must be specified between 0° and 90°.

gr.inqspace()[source]¶

gr.setcoordxform(mat)[source]¶

Change the coordinate transformation according to the given matrix.

Parameters:

mat[3][2] :: 2D transformation matrix

gr.setprojectiontype(projection_type)[source]¶

Set the projection type with this flag.

projection_type :: Projection type

The available options are:

PROJECTION_DEFAULT	0	default
PROJECTION_ORTHOGRAPHIC	1	orthographic
PROJECTION_PERSPECTIVE	2	perspective