# 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.

Parameters:

n :
The number of points
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.

Parameters:

n :
The number of points
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: 

is a replacement for  u which would conflict with   (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).

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.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 :

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

## 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.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.setmarkercolorind(color)[source]

Define the color of subsequent polymarker output primitives.

Parameters:

color :
The polymarker color index (COLOR < 1256)
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

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)

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 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]
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)

## 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

## Control Functions¶

gr.clearws()[source]
gr.updatews()[source]
gr.beginprint(pathname)[source]

Open and activate a print device.

Parameters:

pathname :
Filename for the print device.

beginprint opens an additional graphics output device. The device type is obtained from the given file extension. The following file types are supported:

 .ps, .eps PostScript .pdf Portable Document Format .bmp Windows Bitmap (BMP) .jpeg, .jpg JPEG image file .png Portable Network Graphics file (PNG) .tiff, .tif Tagged Image File Format (TIFF) .fig Xfig vector graphics file .svg Scalable Vector Graphics .wmf Windows Metafile
gr.beginprintext(pathname, mode, fmt, orientation)[source]

Open and activate a print device with the given layout attributes.

Parameters:

pathname :
Filename for the print device.
mode :
Output mode (Color, GrayScale)
fmt :
Output format (see table below)
orientation :
Page orientation (Landscape, Portait)

The available formats are:

 A4 0.210 x 0.297 B5 0.176 x 0.250 Letter 0.216 x 0.279 Legal 0.216 x 0.356 Executive 0.191 x 0.254 A0 0.841 x 1.189 A1 0.594 x 0.841 A2 0.420 x 0.594 A3 0.297 x 0.420 A5 0.148 x 0.210 A6 0.105 x 0.148 A7 0.074 x 0.105 A8 0.052 x 0.074 A9 0.037 x 0.052 B0 1.000 x 1.414 B1 0.500 x 0.707 B10 0.031 x 0.044 B2 0.500 x 0.707 B3 0.353 x 0.500 B4 0.250 x 0.353 B6 0.125 x 0.176 B7 0.088 x 0.125 B8 0.062 x 0.088 B9 0.044 x 0.062 C5E 0.163 x 0.229 Comm10E 0.105 x 0.241 DLE 0.110 x 0.220 Folio 0.210 x 0.330 Ledger 0.432 x 0.279 Tabloid 0.279 x 0.432
gr.endprint()[source]
gr.begingraphics(path)[source]

Open a file for graphics output.

Parameters:

path :
Filename for the graphics file.

begingraphics allows to write all graphics output into a XML-formatted file until the endgraphics functions is called. The resulting file may later be imported with the importgraphics function.

gr.endgraphics()[source]
gr.updategks()[source]
gr.opengks()[source]
gr.closegks()[source]
gr.inqdspsize()[source]
gr.openws(workstation_id, connection, workstation_type)[source]

Open a graphical workstation.

Parameters:

workstation_id :
A workstation identifier.
connection :
A connection identifier.
workstation_type :
The desired workstation type.

Available workstation types:

 5 Workstation Independent Segment Storage 7, 8 Computer Graphics Metafile (CGM binary, clear text) 41 Windows GDI 51 Mac Quickdraw 61 - 64 PostScript (b/w, color) 101, 102 Portable Document Format (plain, compressed) 210 - 213 X Windows 214 Sun Raster file (RF) 215, 218 Graphics Interchange Format (GIF87, GIF89) 216 Motif User Interface Language (UIL) 320 Windows Bitmap (BMP) 321 JPEG image file 322 Portable Network Graphics file (PNG) 323 Tagged Image File Format (TIFF) 370 Xfig vector graphics file 371 Gtk 380 wxWidgets 381 Qt4 382 Scaleable Vector Graphics (SVG) 390 Windows Metafile 400 Quartz 410 Socket driver 415 0MQ driver 420 OpenGL 430 HTML5 Canvas
gr.closews(workstation_id)[source]

Close the specified workstation.

Parameters:

workstation_id :
A workstation identifier.
gr.activatews(workstation_id)[source]

Activate the specified workstation.

Parameters:

workstation_id :
A workstation identifier.
gr.deactivatews(workstation_id)[source]

Deactivate the specified workstation.

Parameters:

workstation_id :
A workstation identifier.
gr.emergencyclosegks()[source]