Glossary

absolute coordinate

a coordinate that is measured from the origin of a coordinate system.

ActiveX

a technology developed by Microsoft that is used to add interactivity to Web pages.

ActiveX control

a type of Web application that is developed specifically for the Windows operating environment. ActiveX controls can provide Web users with interactive capabilities.

area bar chart

a bar chart that applies an additional magnitude of width to the bars that results in categorized bars. Each bar has both a height and a width measure that can be independent of each other.

aspect ratio

the ratio of a shape's width to its height in an output area such as a display, plotter, or film recorder.

axis

a line that represents the midpoints (for a discrete axis) or the scale (for a continuous or interval axis) for graphing variable or data values. An axis typically consists of an axis line with tick marks, tick values (or midpoint values), and a label.

axis area

an area bounded by axes, which might be enclosed by an axis line.

baseline

in a font, the imaginary line upon which the characters rest.

block map

a three-dimensional map that uses blocks of varying heights to represent the value of a variable for each map area.

boundary

in the GMAP procedure, a separating line or point that distinguishes between two or more unit areas or segments.

capline

the highest point of a normal uppercase letter. In some fonts, the capline might be above the top of the letter to allow room for an accent.

Cartesian coordinate system

the two- or three-dimensional coordinate system in which perpendicular axes meet at the origin (0,0) or (0,0,0). Typically, Cartesian coordinate axes are called X, Y, and Z.

cell

in device-based SAS/GRAPH procedures, a unit of measure whose size and shape is determined by both the size of the graphics output area and by the number of rows and columns in the graphics output area.

center point

the location in the GRAPH window that, in conjunction with a radius point, defines the placement and shape of an ellipse or a pie.

CGM

See computer graphics metafile

character up vector

the angle at which a character is positioned. The character up vector has two components, x and y, which determine the angle.

chart statistic

the statistical value calculated for the chart variable: frequency, cumulative frequency, percentage, cumulative percentage, sum, or mean.

chart variable

a variable in the input data set whose values are categories of data represented by bars, blocks, slices, or spines.

chart vertices

points on a radar chart where the statistical values intersect the spokes.

choropleth map

a two-dimensional map that uses color and fill pattern combinations to represent different categories or levels of magnitude.

class variable

See classification variable

classification variable

a variable whose values are used to group (or classify) the observations in a data set into different groups that are meaningful for analysis. A classification variable can have either character or numeric values. Classification variables include group, subgroup, category, and BY variables.

CMYK

A color coding scheme that specifies a color in terms of the levels of cyan, magenta, yellow, and black components. The level of each component ranges from 0 to 255.

color list

the list of foreground colors available for the graphics output. The color list is either the default list established from the style, the list created from the device entry, or the list established from the colors specified with the COLORS= graphics option.

color map

in SAS/GRAPH software, a table that is used to translate the original colors in graphics output to different colors when replaying graphics output using the GREPLAY procedure. The table is contained in a catalog entry.

computer graphics metafile

a graphics output file written in the internationally recognized format for describing computer graphics images. This standardization allows any image in a CGM to be imported and exported among different systems without error or distortion. Short form: CGM.

confidence limits

the upper and lower values of a (usually 95%) confidence interval. In repeated sampling, approximately (1-alpha)*100% of the resulting intervals would contain the true value of the parameter that the interval estimates (where alpha is the confidence level associated with the interval).

contour plot

a three-variable plot that uses line styles or patterns to represent levels of magnitude of z corresponding to x and y coordinates.

coordinate

a value that represents the location of a data point or a graphics element with respect to a coordinate system.

coordinate system

the context in which to interpret coordinates. Coordinate systems vary according to their origin, limits, and units.

data area

the portion of the graphics output area in which data values are displayed. The data area is bounded by axes or map areas. In the Annotate facility, the data area defines a coordinate system.

data tip

data or other detailed information that is displayed when a user positions a mouse pointer over an element in a graph. For example, a data tip typically displays the data value that is represented by a bar, a plot point, or some other element.

density value

a value assigned to each observation in a map data set reflecting the amount of detail (resolution) contributed by the observation.

device driver

in SAS/GRAPH software, a routine that generates the specific machine-language commands needed to display graphics output on a particular device. SAS/GRAPH device drivers take device-independent graphics information produced by SAS/GRAPH procedures and create the commands required to produce the graph on the particular device.

device entry

a SAS catalog entry of type DEV that stores the values of device parameters (or the characteristics) that are used with a particular output device.

device map

a catalog entry used to convert the SAS/GRAPH internal encoding for one or more characters to the device-specific encoding needed to display the characters in hardware text on a particular graphics output device.

device parameter

a value in a device entry that defines a default behavior or characteristic of a device driver. Some device parameters can be overridden by graphics options.

device-independent catalog entry

a SAS catalog entry that contains graphics output in a generic format (not device-specific). A device-independent catalog entry can be replayed on any device supported by SAS/GRAPH software.

device-resident font

a font stored in an output device.

document file

a file output by the Output Delivery System (ODS) that contains an image or is used to view an image. Examples include HTML, PDF, RTF, SVG, and PostScript files.

drill down

to explore data and access information by moving from summary information to more detailed data from which the summary is derived. For example, you could click folders in a hierarchy from the top downwards to find a specific file. Drilling down provides a method of exploring multidimensional data by moving from one level of detail to the next.

fill color

the color of a pattern in a filled, closed graphics object, such as a bar segment, a pie slice, or a map area.

font

a typeface with a specific character shape, spacing, weight, and size. The characters in a font can be figures, symbols, or alphanumeric.

font family

a set of one or more typefaces that share common design characteristics such as serifs, proportional or uniform spacing, or special symbols. For example, Helvetica, Arial, and Albany AMT are members of a sans-serif, proportional font family.

font maximum

in the GFONT procedure, the highest vertical coordinate in a font.

font minimum

in the GFONT procedure, the lowest vertical coordinate in a font.

font units

in the GFONT procedure, units defined by the range of coordinates specified in the font data set. For example, a font in which the vertical coordinates range from 10 to 100 has 90 font units.

FreeType font-rendering

a method of rendering fonts that uses the FreeType engine to access the content of font files in order to render high-quality fonts for ODS and SAS/GRAPH. The FreeType engine can be used in all SAS operating environments.

geo-variable

in a feature table, the $GEOREF formatted variable that stores the spatial information as a geometry object.

geocoding

the process of assigning geographic coordinates (often expressed as latitude and longitude) to other geographic data such as street addresses, or postal codes.

global statement

a SAS statement that you can specify anywhere in a SAS program.

graphics device

See graphics output device

graphics element

a discrete visual part of a picture. For example, a bar in a chart and a plot's axis label are both graphics elements.

graphics object

a discrete visual element of a graph or picture (for example, a bar in a chart, a polygon, a plot's axis, and so on).

graphics option

in a SAS GOPTIONS statement, an option that controls some attribute of the graphics output. The specified value remains in effect only for the duration of the SAS session. Some graphics options override parameters that have been specified for a graphics output device.

graphics output

output from a graphics program that can be stored as a catalog GRSEG entry or as a graphics stream file.

graphics output area

the area of a graphics output device where the graphics output is displayed or drawn. Typically, the graphics output area occupies the full drawing area of the device, but the dimensions of the graphics output area can be changed with graphics options or device parameters.

graphics output device

any terminal, printer, or other output device that is capable of displaying or producing graphical output.

graphics output file

a file that contains bitmapped or vector graphic information.

graphics primitive

a function that draws a graphics element.

graphics stream file

a file that contains device-dependent graphics commands from a SAS/GRAPH device driver. This file can be sent to a graphics device or to other software applications. Short form: GSF.

graphics template

See ODS template

gray scale

a color-coding scheme that specifies a color in terms of gray components. Gray-scale color codes are commonly used with some laser printers and PostScript devices.

grid point

a grid location in the GRAPH window that is marked by a dot. Grid points are used for precision placement of objects.

grid request

in the G3GRID procedure, the request specified in a GRID statement that identifies the horizontal variables that identify the x, y plane and one or more z variables for the interpolation.

group variable

a variable in the input data set used to categorize chart variable values into groups. A group variable enables the data for each distinct group value to be rendered in a visually different manner. For example, a grouped scatter plot displays a distinct marker and color for each group value.

GRSEG

a SAS catalog entry that contains graphic output in a generic, rather than device-specific, format.

GSF

See graphics stream file

handshaking

the exchange of signals between two devices over an interface for control or synchronization purposes. Data flow control is needed to ensure that data are not sent faster than the receiving device can process them. Handshaking usually involves sending signals between the device and the host computer in order to start and stop transmission of data.

hardcopy device

See graphics output device

hardware character set

a set of character definitions held internally in a graphics output device. When a hardware character set is used, SAS/GRAPH software does not have to send the device all the commands to draw characters, only the corresponding character codes. Some devices have more than one hardware character set.

hardware handshaking

a method of data flow control in which the flow of data between the computer and device is regulated by signals sent over separate wires in the connecting cable.

hatch

a fill pattern consisting of parallel lines at any specified angle.

HLS

a color-coding scheme that specifies a color in terms of its hue, lightness, and saturation components. Hue is the color, lightness is the percentage of white, and saturation is the attribute of a color that determines its relative strength and its departure from gray. Lightness and saturation added to the hue produce a specific shade.

host computer

a workstation or minicomputer accessed by a terminal or another workstation.

host font-rendering

a method of rendering fonts that relies on the capabilities of the operating environment.

HSV model

a color-coding scheme that specifies a color in terms of its hue, saturation, and value components. Hue is the color. Saturation is the aspect of a color that determines its relative strength and departure from gray. And value, or brightness, is the color's departure from black.

identification variable

a variable common to both the map data set and the response data set that the GMAP procedure uses to associate each pair of map coordinates and each response value with a unique map area.

image file

a file that contains bitmapped graphic information. Examples include GIF, PNG, TIFF, and JPEG files. Image files are a subset of graphics output files.

image map

a diagram that associates graphic elements with HTML links to implement drill-down functionality. The graphic elements are represented by sets of coordinates.

import

to restore a SAS transport file to its original form (a SAS library, a SAS catalog, or a SAS data set) in the format that is appropriate for the host operating system. You use the CIMPORT procedure to import a SAS transport file that was created by the CPORT procedure.

include

in the graphics editor, to read in or link to a graph other than the one currently being edited.

interactive graph

output that features user controls such as menus, buttons, and pictures that a user can manipulate. The controls are driven by a Java applet or an ActiveX control.

interpolate

to estimate values that are between two or more known values.

Joint Photographic Experts Group

an industry-standard file format for compressed images. Saving an image in JPEG format typically provides 10:1 compression with little perceptible loss in image quality. Short form: JPEG.

JPEG

See Joint Photographic Experts Group

justify

to position text in relation to the left or right margin or the center of the line.

key map

a SAS catalog entry used to translate the codes generated by the keys on a keyboard into their corresponding SAS/GRAPH internal character encoding.

label

descriptive text associated with a variable. By default, this text is the name of a variable or of a label previously assigned with the LABEL= option.

latitude

used with maps, the angular measure between the equator and the circle of parallel on which a point lies.

library reference

See libref

libref

a SAS name that is associated with the location of a SAS library. For example, in the name MYLIB.MYFILE, MYLIB is the libref, and MYFILE is a file in the SAS library.

link to

in the graphics editor, to include one graph into another by placing a template of that graph in the current graph. The template acts as a placeholder and can be resized; it creates a connection between the graph being edited and the linked-to graph such that any changes made to the linked-to graph are reflected in the graph where a template is placed.

longitude

used with maps, the angular measure between the reference meridian and the plane intersecting both poles and a point. The reference meridian, called the prime meridian, is assigned a longitude of 0, and other longitude values are measured from there in appropriate angular units (degrees or radians, for example).

major axis

in the graphics editor, the longest axis of a graphics object.

major tick marks

the points on an axis that mark the major divisions of the axis scale.

map

a graphic representation of an area. The area is often a geographic area, but it can also be any other area of any size.

map area

See unit area

map data set

a SAS data set that contains variables whose values are the X and Y coordinates that define the points on the boundaries of map areas. In addition, each observation contains an identification variable whose value identifies the map area for that point such as a state or county.

mapping

the process of displaying data values on a map.

marker

a symbol such as a diamond, a circle, or a triangle that is used to indicate the location of, or annotate, a data point in a plot or graph.

meridian

an imaginary circle of constant longitude around the surface of the earth perpendicular to the equator.

metafile

a file, produced by the Metagraphics facility internal driver, that contains device-independent graphics commands in a special format. A user-written external driver routine is required to read and process the metafile.

Metagraphics driver

a type of SAS/GRAPH device driver that can be written by users. A Metagraphics driver consists of an internal driver (supplied with SAS/GRAPH software), which writes a metafile in a special format, and an external driver (written by the user), which decodes the metafile and writes device-specific commands.

midpoint

a value that represents the middle of a range of data values.

minor axis

in the graphics editor, the shortest axis of a graphics object.

minor tick marks

the divisions of an axis scale that fall between major tick marks.

needle plot

a plot in which data points are connected by a vertical line which connects to a horizontal baseline. The baseline intersects the 0 value, or the minimum value on the vertical axis.

node

a connection point between two or more links. In a node/link diagram, nodes are typically represented as a box and enable you to access information and possibly to traverse the graph by drilling up or down in the structure.

ODS template

a description of how output should appear when it is formatted. ODS templates are stored as compiled entries in a template store, also known as an item store. Common template types include STATGRAPH, STYLE, CROSSTABS, TAGSET, and TABLE.

offset

the distance between a graphics object's original position and its new position when it is moved. Offsets can be specified for legends, axes, an entire graph, or other graphics object.

origin

in a three-dimensional graph, the point at which the X, Y, and Z axes intersect. In a two-dimensional graph, the point at which the X and Y axes intersect.

panel

in the GREPLAY procedure, a part of the template in which one or more pictures can be displayed. A template can contain one or more panels.

parallel

an imaginary circle of constant latitude around the surface of the earth parallel to the equator.

pattern type

in SAS/GRAPH software, the set of fill patterns that are valid for a particular type of graph. The PATTERN statement supports three pattern types: bar and block patterns, map and plot patterns, and pie and star patterns.

pie chart

a circular chart that is divided into slices by radial lines. Each slice represents the relative contribution of each part to the whole.

pixel

an element of an electronic image. A pixel is the smallest element on a display that can be assigned a separate color.

plot

a visual representation of data such as a scatter plot, needle plot, or contour plot.

plot line

the line joining the data points in a plot.

plotter

a class of graphics devices that typically use pens to draw hard-copy output.

PNG

See Portable Network Graphic

polygon font

a SAS/GRAPH font in which the characters are drawn with enclosed areas that can be either filled or empty.

polyline

in SAS/GRAPH software, a graphics object composed of connected line segments that might have attributes. A polyline is not a closed object; therefore, it cannot be filled with a pattern.

Portable Network Graphic

a file format that returns the graphical output in separate files and that produces a static image. This format is similar to the GIF format, but has additional features, such as support for true-color images and better compression. Short form: PNG.

PostScript

a device-independent page description language for printing high-resolution integrated text and graphics.

predefined color

one of the set of colors for which SAS/GRAPH software defines and recognizes names (for example, BLACK, BLUE, and CYAN).

prism map

a three-dimensional map that uses prisms (polyhedrons with two parallel surfaces) of varying height to indicate the ordinal magnitude of a response variable.

procedure output area

the portion of the graphics output area where the output from a graphics procedure is displayed.

projection

a two-dimensional map representation of unit areas on the surface of a sphere (for example, geographic regions on the surface of the Earth).

prompt character

a character sent by the host computer to a device to signal that the host has finished transmitting data and is ready for a response from the device.

protocol

a set of rules that govern data communications between computers, between computers and peripheral devices, and between software applications. TCP/IP, FTP, and HTTP are examples of protocols.

radar chart

a chart that shows the relative frequency of data measures with statistics displayed along spokes that radiate from the center of the chart. The charts are often stacked on top of one another with circular reference lines, thus giving them the look of a radar screen.

rasterizer

a device that accepts commands (such as moves and draws) as input and that converts those commands into a bit-map. Rasterizers are connected between host computers and graphics output devices that require bitmapped input.

region

in the graphics editor, an area in the GRAPH window containing more than one graphics objects.

regression analysis

an analysis that models a dependent (or response) variable as a function of one or more independent (or predictor) variables. The regression line, which is the set of predictions from the model, appears as a line or curve in a plot of the dependent variable against an independent variable.

relative coordinate

a coordinate that is measured from a point other than the origin. In the Annotate facility, this point is usually the endpoint of the last graphics element that was drawn.

replay

in SAS/GRAPH software, to display graphics output that is stored in a catalog entry using the GREPLAY procedure.

response data set

a SAS data set used by the GMAP procedure that contains data values associated with map areas and one or more identification variables.

response levels

the individual values or ranges of values into which the GMAP or GCHART procedure divides the response variable.

response values

values of a response variable that the GMAP procedure represents on a map as different pattern/color combinations, or as raised map areas (prisms), spikes, or blocks of different heights. The GCHART procedure represents response values as bars, slices, spines, or blocks.

response variable

in the GMAP procedure, a variable in the response data set that contains data values that are associated with a map area.

RGB color model

a color-coding scheme that specifies a color in terms of amounts of red, green, and blue components.

SAS/GRAPH font

a font stored in the SASHELP.FONTS catalog, and a font created by the user and stored in a GFONTn catalog. These fonts can be used only by SAS/GRAPH procedures or other procedures that generate GRSEG output files. Examples of SAS/GRAPH fonts include Swiss, Simulate, and Marker. These fonts are provided for specialized purposes only.

scatter plot

a two- or three-dimensional plot that shows the joint variation of two (or three) variables from a group of table rows. The coordinates of each point in the plot correspond to the data values for a single table row (observation).

snap

in the graphics editor, to automatically place graphics objects in the grid display area with precision.

software handshaking

a method of data flow control in which a device and a computer exchange predefined sequences of characters to indicate when data should be transmitted between the two.

spine

a line on a star chart used to represent the relative value of the chart statistic for a midpoint. Spines are drawn outward from the center of the chart.

spline

a method of interpolation in which a smooth line or surface connects data points.

spokes

lines that radiate from the center of a radar or star chart. These lines represent statistical information.

standard deviation

a statistical measure of the variability of a group of data values. This measure, which is the most widely used measure of the dispersion of a frequency distribution, is equal to the square root of the variance.

star chart

a chart that shows the values of chart statistics as either spines of varying lengths or slices of varying sizes. Star charts display statistics in a circle surrounding the spines or slices. See radar chart.

static graph

SAS/GRAPH output in the form of an image.

stroked font

in SAS/GRAPH software, a font in which the characters are drawn with discrete line segments or circular arcs.

style attribute

a visual property such as a color, line pattern, or font property that has a reserved name. For example, COLOR, FONTFAMILY, FONTSIZE, FONTWEIGHT, and FONTSTYLE are all attributes of style elements such as GraphTitleText, GraphLabelText, and so on. Style attributes are collectively referenced by a style element within a style definition.

subgroup variable

the variable in the input data set for a chart that is used to proportionally fill areas of the bars or blocks on a bar chart, or to identify separate rings of a pie chart.

summary variable

a variable in an input data set whose values some SAS/GRAPH procedures total or average to produce the sum or mean statistics, respectively.

surface map

a three-dimensional map that uses spikes of varying heights to indicate levels of relative magnitude.

surface plot

a three-dimensional graph that displays values of a vertical Z variable based on gridded X and Y variables.

system font

a font that can be used by any SAS procedure and by other software such as Microsoft Word. These fonts include TrueType and Type1 fonts. Examples of system fonts include Albany AMT, Monotype Sorts, and Arial.

template

a specification of an area or areas on a page. A GREPLAY template defines a layout in which you can display one or more graphs on a single page.

thumbnail

a small image that can be selected in order to display a larger image.

TIFF

Tagged Image File Format. An industry-standard file format for storing compressed images. The Tagged Image File Format specifies compression routines and file formats for a variety of image types, including bilevel, grayscale, and color.

tile chart

See treemap

tilt angle

the measure in degrees from the horizontal axis to the major axis of an object.

tool palette

the collection of icons that represent functions in the interface.

tooltip

descriptive text that appears when a cursor is placed over certain elements of a graphical user interface, such as the tool icons in a toolbar.

transformation

in the DATA Step Graphics Interface (DSGI), a mapping of the window coordinates to the viewport coordinates.

translate

to change the location of a graphics object.

treemap

a graph that represents the relative values of data by using rectangular areas. The color of each area represents the value of one measure in the query. The size of each area represents the value of the another measure in the query. ( In SAS/GRAPH a treemap is created with the GTILE procedure.)

typeface

a set of characters with a common design, represented by one or more fonts that differ in weight, orientation, width, size, and spacing. For example, Arial, Arial Bold, Arial Italic, and Arial Bold Italic share the same typeface (Arial), but differ in their orientation and weight.

unit

a single quantity of measurement. In SAS/GRAPH software, units can represent any of the following: centimeters, percentages, points, inches, or cells.

unit area

a polygon or group of polygons on a map. For example, states, provinces, and countries are typical map areas. In a map data set, a map area consists of all the observations that have the same values for the identification variable or variables.

view

a definition of a virtual data set that is named and stored for later use. A view contains no data; it merely describes or defines data that is stored elsewhere.

Web server

a computer program that delivers (serves) content, such as web pages, over the World Wide Web. It can also refer to the computer or virtual machine that runs the program.

XON/XOFF handshaking

a method of data flow control in which the flow of data between a computer and a device is regulated by the transmission of XON (DC1) and XOFF (DC3) control characters between the device and the computer.