Graphics and Plotting Keywords

An alignment of 0.0 (the default) places the left edge of the text on the given (x, y) coordinate (left-justifies). An alignment of 1.0 right-justifies the text, while 0.5 centers the text over point (x, y).

Specifies the horizontal alignment of the text in relation to the point x, y, which is specified as input to the XYOUTS procedure.

Ax Keyword

SHADE_SURF

SHADE_SURF_IRR

The Ax keyword parameter defaults to +30 degrees if omitted and !P.T3d is 0.

Specifies the angle of rotation about the x-axis, in degrees, towards the viewer.

NOTE: This keyword is effective only if !P.T3d is not set. If !P.T3d is set, the three-dimensional to two-dimensional transformation used by SURFACE is contained in the 4-by-4 array !P.T.

The surface represented by the two-dimensional array is first rotated, Az (see the next section) degrees about the z-axis, then by Ax degrees about the x-axis, tilting the surface towards the viewer (Ax

0), or away from the viewer.

The 3D to 2D transformation represented by Ax and Az can be saved in !P.T by including the Save plotting keyword.

Az Keyword

SHADE_SURF

SHADE_SURF_IRR

This keyword is effective only if !P.T3d is not set. The order of rotation is Az first, then Ax.

Specifies the counterclockwise angle in degrees of rotation about the z-axis (when looking down the z-axis toward the origin).

Background Keyword

Corresponding System Variable: !P.Background.

The background color index to which the screen is set when the ERASE procedure is called.

NOTE: Not all devices support erasing the background to a color index.

Example

To produce a black plot with a white background on a color display:

PLOT, y, Background = 255, Color = 0

Bottom Keyword

The color index used to draw the lower part of the surface. If not specified, the bottom is drawn with the same color as the top.

NOTE: If the X rotation is between 90 and 270 degrees, the top of the surface will be colored with the color set by the Bottom keyword.

Box Keyword

Corresponding System Variable: !PDT.Box

Places a box around the labels in a Date/Time axis. If you set the keyword to a value of 1, boxes are drawn around all the labels of the Date/Time axis. (Default: no boxes are drawn)

C_Annotation Keyword

Usually, contours are labeled with their value. This parameter, a vector of strings, allows any text to be specified. The first label is used for the first contour drawn, and so forth. If the Levels keyword is specified, the elements of C_Annotation correspond directly to the levels specified, otherwise, they correspond to the default levels chosen by the contour procedure. If there are more contour levels than elements in C_Annotation, the remaining levels are labeled with their values.

Sets the label that will be drawn on each contour.

NOTE: If the CONTOUR2 Fill keyword is used, labeling is disabled. Refer to the description of CONTOUR2 in the PV-WAVE Reference for an example of how to create a filled contour plot with labels.

Example

To produce a contour plot with three levels labeled "low", "medium", and "high":

CONTOUR, Z, Levels = [0.0, 0.5, 1.0], $
    C_Annotation = ["low", "medium", "high"]

Use of this keyword implies use of the Follow keyword.

C_Charsize Keyword

Sets the size of the characters used to annotate contour labels.

Normally, contour labels are drawn at three-fourths the size used for the axis labels (specified by the Charsize keyword or !P.Charsize system variable). This keyword allows the contour label size to be specified independently. Use of this keyword implies use of the Follow keyword.

NOTE: If the CONTOUR2 Fill keyword is used, labeling is disabled. Refer to the description of CONTOUR2 in the PV-WAVE Reference for an example of how to create a filled contour plot with labels.

C_Charthick Keyword

Corresponding System Variable: !P.Charthick

Sets the thickness of contour label characters drawn with the software fonts. Normal thickness is 1.0, double thickness is 2.0, etc. If this keyword is omitted, the value of the system variable !P.Charthick is used.

NOTE: If the CONTOUR2 Fill keyword is used, labeling is disabled. Refer to the description of CONTOUR2 in the PV-WAVE Reference for an example of how to create a filled contour plot with labels.

C_Colors Keyword

This parameter is a vector, converted to integer type if necessary. If there are more contour levels than elements in C_Colors, the elements of the color vector are cyclically repeated.

A vector of color indices used to set the color index used to draw each contour.

Example

If C_Colors contains three elements, and there are seven contour levels to be drawn, the colors c₀, c₁, c₂, c₀, c₁, c₂, c₀ will be used for the seven levels. To call CONTOUR and set the colors to [100, 150, 200]:

CONTOUR, Z, C_Colors = [100, 150, 200]

C_Labels Keyword

C_Labels allows you to override this default and explicitly specify the levels to label. This parameter is a vector, converted to integer type if necessary. If the Levels keyword is specified, the elements of C_Labels correspond directly to the levels specified, otherwise, they correspond to the default levels chosen by CONTOUR. Setting an element of the vector to zero causes that contour label to not be labeled. A nonzero value forces labeling.

Specifies which contour levels should be labeled. By default, every other contour level is labeled.

NOTE: If the CONTOUR2 Fill keyword is used, labeling is disabled. Refer to the description of CONTOUR2 in the PV-WAVE Reference for an example of how to create a filled contour plot with labels.

Example

To produce a contour plot with four levels where all but the third level is labeled:

CONTOUR, Z, Levels = [0.0, 0.25, 0.75, 1.0], $
    C_Labels = [1, 1, 0, 1]

Use of this keyword implies use of the Follow keyword.

C_Linestyle Keyword

As with C_Colors, C_Linestyle is a vector of linestyle indices. If there are more contour levels than linestyles, the linestyles are cyclically repeated. The following table lists the available linestyles and their keyword indices:

Specifies the linestyle used to draw each contour.


Index	X Windows Style	Windows Style
0	Solid	Solid
1	Dotted	Short dashes
2	Dashed	Long dashes
3	Dash dot	Long-short dashes
4	Dash-dot-dot-dot	Long-short-short dashes
5	Long dashes	Long dashes

NOTE: The current contouring algorithm draws all the contours in each cell, rather than following contours. Hence, some of the more complicated linestyles will not be suitable for some applications.

Example

To produce a contour plot, with the contour levels directly specified in a vector V, with all negative contours drawn with dotted (UNIX/OpenVMS) or dashed (Windows) lines, and with positive levels in solid lines:

CONTOUR, Z, Levels = V, C_Linestyle = V LT 0.0

C_Thick Keyword

Specifies the line thickness of lines used to draw each contour level. As with C_Colors, C_Thick is a vector of line thickness values, although the values are floating-point. If there are more contours than thickness elements, elements are repeated. If omitted, the overall line thickness specified by the Thick keyword parameter or !P.Thick is used for all contours.

Channel Keyword

Specifies the destination channel index or mask for the operation. This parameter is used only with devices that have multiple display channels. (Default: zero)

Charsize Keyword

Corresponding System Variable: !P.Charsize

Sets the overall character size for the annotation. A Charsize of 1.0 is normal. The size of the annotation on the axes may be set, relative to Charsize, with XCharsize, YCharsize, and ZCharsize. The main title is written with a character size of 1.25 times this parameter.

NOTE: If you use !P.Multi to create a multiple plot of more than two rows or columns, PV-WAVE decreases the character size by a factor of two.

Charthick Keyword

Corresponding System Variable: !P.Charthick

Sets the thickness of characters drawn with the software fonts. Normal thickness is 1.0, double thickness is 2.0, etc. If this keyword is omitted, the value of the system variable !P.Charthick is used.

Clip Keyword

The rectangle is specified as a vector of the form [X₀, Y₀, X₁, Y₁], giving coordinates of the lower-left and upper-right corners, respectively. Coordinates are specified in data coordinate units unless an overriding coordinate keyword is present, such as Normal or Device.

Specifies the coordinates of a rectangle used to clip the graphics output. Graphics that fall inside the rectangle are displayed; graphics that fall outside the clipping rectangle are not displayed.

Color Keyword

Corresponding System Variable: !P.Color

Sets the color index of text, lines, solid polygon fill, data, axes, and annotation. If this keyword is omitted, !P.Color specifies the color index.

When used with PLOT, OPLOT, and PLOTS, the Color keyword can specify an array of color values. If an array is used, each color value in the array is applied, in order, to color the line segments and/or plot symbols that make up the graph. The colors are repeated, as needed, to complete the entire graph of the data set. In addition, when an array is specified, the !P.Color system variable is used to color the axes (rather than using one of the data colors). Negative values in a Color array create transparent data segments (in other words, no line segment is drawn for that data interval).

NOTE: You cannot specify an array of values for the !P.Color system variable. The array of color values can only be used with the Color keyword.

Example 1

TEK_COLOR
!P.Color=10
PLOT, FINDGEN(10), Color=[2,3,5]

;  Axes drawn in color 10.

;  The 9 line segments are drawn in colors 2, 3, 5, 2, 3, 5, 2, 3, 5.

Example 2

Plot data containing "missing" values by using the fact that negative colors are "transparent".

data = HANNING(50)

; Create some data.

data([5, 6, 10, 20, 25, 30, 31]) = -1

; Flag some data as "missing" (= -1).

PLOT, data, PSym=-5, YRange=[0,1]

; Normal plot with lots of spikes.

col = REPLICATE(!P.Color, 50)

; Array of plot colors.

missing = WHERE(data eq -1)

; Indices of missing points.

col(missing) = -1

; Symbols on the missing points and line segments to the right of

; missing points are transparent.

PLOT, data, PSym=5, YRange=[0,1], Color=col

; Draw plot symbols.

col(missing-1) = -1

; Line segments to the left of missing points are also transparent.

OPLOT, data, Color=col

; Overlay lines with segments missing.

Compress Keyword

Corresponding System Variable: !PDT.Compress

PLOT,

OPLOT

Compresses out weekends and holidays from a Date/Time axis. Before you can use this keyword, you must define holidays or weekends with the procedures CREATE_HOLIDAYS and CREATE_WEEKENDS.

Data Keyword

A keyword flag, which if present, indicates that the coordinates are specified in data coordinates (the default). When used with AXIS, CONTOUR, CONTOUR2, OPLOT, PLOT, SHADE_SURF, and SURFACE, this keyword specifies that the Position and Clip coordinates are in data units.

Device Keyword

The following code displays an image contained in the variable A and then draws a contour plot of pixels (100:499, 100:399) registered over the pixels:

Express coordinates in device coordinates. When used with AXIS, CONTOUR, CONTOUR2, OPLOT, PLOT, SHADE_SURF, and SURFACE, this keyword specifies that the Position and Clip coordinates are in device units.

Example

TV, A

; Display the image.

CONTOUR, A(100:499, 100:399), Position = $

[100,100, 499,399], /Device, /Noerase, $
XStyle = 1, YStyle = 1

; Draw the contour plot, specify the coordinates of the plot, in
; device coordinates, do not erase, set the X and Y axis styles
; to EXACT.

Note that in the above example, the keyword specification /Device is equivalent to Device = 1.

DT_Range Keyword

Corresponding System Variable: !PDT.DT_Range

Sets an exact range of values in a Date/Time axis. You must specify the desired start and end values from a Date/Time Julian value. The range may be adjusted slightly by the PLOT procedure, depending on the data. To obtain an exact range set the XStyle plotting keyword to two. For more information, see XStyle.

Fill_Pattern Keyword

POLYFILL

PIE_CHART

The hardware-dependent fill pattern index for the POLYFILL and PLOTS procedures. If omitted or set to 0, a solid fill results.

Follow Keyword

CONTOUR can draw contours using one of two different methods:

If present and nonzero, forces the CONTOUR procedure to use the line-following method instead of the cell-drawing method.

The cell-drawing method, used by default, examines each array cell and draws all contours emanating from that cell before proceeding to the next cell. This method is efficient in terms of computer resources but does not allow contour labeling.
The line-following method searches for each contour line and then follows the line until it reaches a boundary or closes. This method gives better looking results with dashed linestyles, and allows contour labeling, but requires more computer time. It is used if any of the following keywords is specified: C_Annotation, C_Charsize, C_Charthick, C_Labels, Follow, or Path_Filename.

Although these two methods both draw correct contour maps, differences in their algorithms can cause small differences in the resulting plot.

Font Keyword

Corresponding System Variable: !P.Font

An integer that specifies the graphics text font index.

Font index -1 selects the software fonts, which are drawn using vectors. Font number 0 selects the hardware font of the output device. See Chapter 10, Software Fonts, in the PV-WAVE User's Guide. for a complete description of the software fonts. See Appendix , Output Devices and Window Systems for more information on the hardware fonts available with each supported output device.

NOTE: Hardware font drivers that support 3D transformations include X Windows, WIN32 (on Windows NT platforms only), PostScript, and WMF (on Windows NT platforms only).

Gridstyle Keyword

Corresponding System Variable: !P.Gridstyle

Lets you change the linestyle of tick intervals.

The default is a solid line. Other linestyle choices and their index values are listed in the following table:


Index	X Windows Style	Windows Style
0	Solid (default)	Solid (default)
1	Dotted	Short dashes
2	Dashed	Long dashes
3	Dash dot	Long-short dashes
4	Dash-dot-dot-dot	Long-short-short dashes
5	Long dashes	Long dashes

One possible use for this keyword is to create an evenly spaced grid consisting of dashed lines across your plot region. To do this, first set the Ticklen keyword to 0.5. This ensures that the dashed tick style will appear correctly on your plot. Then set the Gridstyle keyword to the style you want to use. For example:

PLOT, mydata, Ticklen = 0.5, Gridstyle = 2

produces a plot with a dashed grid across the entire plot region.

Horizontal Keyword

If set, causes SURFACE to only draw lines across the plot perpendicular to the line of sight. The default is for SURFACE to draw both across the plot and from front to back.

Levels Keyword

A contour is drawn for each level specified in Levels. If omitted, the data range is divided into approximately six equally-spaced levels.

Specifies a vector containing the contour levels (maximum of 150) drawn by the CONTOUR and CONTOUR2 procedures.

Example

To draw a contour plot with levels at 1, 100, 1000, and 10000:

CONTOUR, Z, Levels = [1, 100, 1000, 10000]

To draw a contour plot with levels at 50, 60, ..., 90, 100:

CONTOUR, Z, Levels = FINDGEN(6) * 10 + 50

Line_Fill Keyword

POLYFILL

PIE_CHART

Indicates that polygons are to be filled with parallel lines, rather than using solid or patterned filling methods.

When using the line-drawing method of filling, the thickness, linestyle, orientation, and spacing of the lines may be specified with keywords.

Linestyle Keyword

Corresponding System Variable: !P.Linestyle

Specifies the linestyle used to draw the lines or connect data points.

UNIX and OpenVMS Users: The line join style is "miter," i.e., the outer edges of two lines extend to meet at an angle.

Windows Users: The line join style is "round."

The linestyle index is an integer, as shown in the following table:


Index	X Windows Style	Windows Style
0	Solid	Solid
1	Dotted	Short dashes
2	Dashed	Long dashes
3	Dash dot	Long-short dashes
4	Dash-dot-dot-dot	Long-short-short dashes
5	Long dashes	Long dashes

Lower_Only Keyword

Indicates that only the lower surface of the object is to be drawn.

Max_Levels Keyword

Corresponding System Variable: !PDT.Max_Levels

Sets the maximum number of levels on a Date/Time axis. For example, assume that the Date/Time data contains years, months, days, hours, minutes, and seconds. If this keyword is set to three, then the Date/Time axis will show three levels: seconds, minutes, and hours.

Max_Value Keyword

Data points with values equal to or above this value are ignored when contouring. Cells containing one or more corners with values above Max_Value will have no contours drawn through them.

Month_Abbr Keyword

Corresponding System Variable: !PDT.Month_Abbr

Abbreviates month or quarter names to either three characters or one character, depending on the space available on the Date/Time axis. If a one-character abbreviation does not fit, no label is used. If the complete label can fit, it is not abbreviated, even if the keyword is specified. Month names are specified in the system variable !Month_Names. Quarter names are specified in the !Quarter_Names system variable.

NLevels Keyword

If the Levels parameter, which explicitly specifies the value of the contour levels, is present this keyword has no effect. If neither parameter is present approximately six levels are drawn.

The number of equally-spaced contour levels that are produced by CONTOUR and CONTOUR2. The maximum is 150. (Default: 6)

If the minimum and maximum Z values are Z_min and Z_max, then the value of the ith level is:

Z_min + (i + 1)(Z_max - Z_min)/(NLevels + 1)

where i ranges from 0 to NLevels - 1.

Noclip Keyword

Corresponding System Variable: !P.Noclip

For PLOT, CONTOUR, CONTOUR2, and SURFACE, enforces the default clipping behavior, which is to clip graphics at the boundary of the Plot Data Region (area bounded by the coordinate axes). For OPLOT, PLOTS, POLYFILL, and XYOUTS, disables clipping altogether, allowing text and graphics to be drawn anywhere in the Device Area.

Nodata Keyword

To draw an empty set of axes between some given values:

If this keyword is set, only the axes, titles, and annotation are drawn. No data points are plotted.

Example

PLOT, [XMIN, XMAX], [YMIN, YMAX], /Nodata

Noerase Keyword

Specifies that the screen or page is not to be erased. By default the screen is erased, or a new page is begun, before a plot is produced.

Normal Keyword

When used with AXIS, CONTOUR, CONTOUR2, OPLOT, PLOT, SHADE_SURF, and SURFACE, indicates that the Clip and/or Position coordinates are in the normalized coordinate system and range from 0.0 to 1.0.

Indicates that the coordinates are in the normalized coordinate system and range from 0.0 to 1.0.

{CONTOUR_HEADER, TYPE : 0B, HIGH : 0B, $
    LEVEL : 0, NUM : 0L, VALUE : 0.0}

The fields are:

TYPE A byte which is zero if the contour is open, and one if it is closed.
HIGH A byte which is 1 if the contour is closed and above its surroundings, and is 0 if the contour is below. This field is meaningless if the contour is not closed.
LEVEL A short integer with value greater than or equal to zero. (It is an index into the Levels array).
NUM The longword number of data points in the contour.
VALUE The contour value. This a single-precision floating-point value.

Following the header in each record are NUM pairs of single-precision floating (x,y) values, expressed in normalized coordinates.

The CONTOURFILL procedure can be used along with this file to fill the contours with specified colors or patterns. You can use CONTOUR with the Path_Filename keyword to get the path information and then use CONTOURFILL to fill the closed contours.

Use of this keyword implies use of the Follow keyword.

Pattern Keyword

If this keyword parameter is omitted, POLYFILL fills the area with a solid color. The pattern array may be of any size; if it is smaller than the filled area the pattern array is cyclically repeated.

A rectangular array of pixels (3D for CONTOURFILL) giving the fill pattern.

Windows Users: The Pattern keyword is not available for the PLOTS or POLYFILL procedure.

Example

To fill the current plot window with a grid of dots:

Pattern = BYTARR(10, 10)

; Define pattern array as 10-by-10.

Pattern(5,5) = 255

; Set center pixel to bright.

POLYFILL, !X.Window([0, 1, 1, 0]), $
    !Y.Window([0, 0, 1, 1]), /Normal, Pattern = Pattern

; Fill the rectangle defined by the four corners of the window with the pattern.

PClip Keyword

Forces PLOTS, POLYFILL, and XYOUTS to accept the value of !P.Clip as the clipping rectangle. Usually, this is the area bounded by the coordinate axes. By default, these routines ignore !P.Clip, allowing you to place text and graphics outside the Data Plot Region.

Polar Keyword

OPLOT

Polar plots are produced when this keyword is present and nonzero.

The X and Y vector parameters, both of which must be present, are first converted from polar to cartesian coordinates. The first parameter is the radius, and the second is , expressed in radians.

To make a polar plot:

PLOT, /Polar, R, Theta

Position Keyword

Corresponding System Variable: !P.Position

Allows direct specification of the plot window.

Position is a four-element vector giving, in order, the coordinates [(x₀, y₀), (x₁, y₁)] of the lower-left and upper-right corners of the data window. Coordinates are expressed in normalized units ranging from 0.0 to 1.0, unless the keyword Device is present, in which case they are in actual device units.

When setting the position of the window, be sure to allow space for the annotation, which resides outside the window. PV-WAVE outputs the message

%, Warning: Plot truncated.

if the plot region is larger than the screen or page size. The plot region is the rectangle enclosing the plot window and the annotation.

When plotting in three dimensions, the Position keyword is a six-element vector with the first four elements describing, as above, the XY position, and with the last two elements giving the minimum and maximum z-coordinates. The Z specification is always in normalized coordinate units.

When making more than one plot per page it is more convenient to set !P.Multi than to manipulate the position of the plot directly with the Position keyword.

Example

The following statement produces a contour plot with data plotted in only the upper-left quarter of the screen:

CONTOUR, Z, Position = [0.0, 0.5, 0.5, 1.0]

Because no space on the left or top edges was allowed for the axes or their annotation, the warning message described above results.

Psym Keyword

Corresponding System Variable: !P.Psym

Specifies by reference number a symbol used to mark each data point. The available symbols and their corresponding reference numbers are shown in the following figure.

Figure 3-1 The plot symbols and their corresponding reference numbers.

Normally, Psym is 0, data points are

Figure 3-1

Symsize

Negative values of Psym cause the symbol designated by |Psym| to be plotted at each point with solid lines connecting the symbols. For example, a Psym value of -5 plots triangles at each data point and connects the points with lines.

The USERSYM procedure is used to create a user-defined symbol (number 8).

For symbol number 10, Histogram, data points are plotted in the histogram mode. Horizontal and vertical lines are connect the plotted points, as opposed to the normal method of connecting points with straight lines.

When used with PLOT, OPLOT, and PLOTS, the Psym keyword can specify an array of plot symbols. If an array is used, each plot symbol value in the array is applied, in order, to create the plot symbols that make up the graph. The symbols are repeated, as needed, to complete the entire graph of the data set.

NOTE: You cannot specify an array of values for the !P.Psym system variable. The array of color values can only be used with the Psym keyword.

Example

The following code plots an array using points, and then overplots the smoothed array, connecting the points with lines:

PLOT, A, Psym = 3

; Plot using points.

OPLOT, SMOOTH(A, 7)

; Overplot smoothed data.

Save Keyword

Use this keyword when combining the output of SURFACE and SHADE_SURF with the output of other routines in the same plot.

Saves the 3D to 2D transformation matrix established by SURFACE and SHADE_SURF, and specified by the Ax and Az keywords, in the system variable field !P.T.

When used with AXIS, the Save keyword parameter saves the scaling parameters established by the call back in the appropriate axis system variable, !X, !Y, or !Z. This causes subsequent overplots to be scaled to the new axis.

Example

To display a two-dimensional array using SURFACE, and to then superimpose contours over the surface: (This example assumes that !P.T3d is zero, its default value.)

SURFACE, Z, /Save

; Make a surface plot and save the transformation.

CONTOUR, Z, /Noerase, /T3d

; Make contours, don't erase, use the 3D to 2D transform placed in
; !P.T by SURFACE.

To display a surface and to then display a flat contour plot, registered above the surface:

SURFACE, Z, /Save

; Make the surface, save transform.

CONTOUR, Z, /Noerase, /T3d, ZValue = 1.0

; Now display a flat contour plot, at the maximum Z value (normalized
; coordinates). You can display the contour plot below the surface

; with a ZValue of 0.0.

Size Keyword

XYOUTS

Specifies the character size as a factor of the normal character size. Normal size is 1.0.

Skirt Keyword

draws the surface of A with a skirt at the Z value 100.

A skirt around the array at a given z value is drawn if this keyword parameter is present. The z value is expressed in data units.

For example:

SURFACE, A, Skirt = 100

If the skirt is drawn, each point on the four edges of the surface is connected to a point on the skirt which has the given z value, and the same x and y values as the edge point. In addition, each point on the skirt is connected to its neighbor.

Solid_Psym Keyword

OPLOT

When present and nonzero, symbols are drawn with solid lines no matter which linestyle is used to connect the symbols. By default, symbols are drawn with the currently specified linestyle.

Spacing Keyword

POLYFILL

PIE_CHART

Specifies the spacing, in centimeters, between the parallel lines used to fill polygons.

Spline Keyword

Use of this keyword implies the use of the Follow keyword. The appearance of contour plots of arrays with low resolution may be improved by using spline interpolation. In rare cases, contour lines that are close together may cross because of interpolation.

Specifies that contour paths are to be interpolated using cubic splines.

Splines are especially useful with small data sets (less than 15 array dimensions). With larger data sets the smoothing is not as noticeable and the expense of splines increases rapidly with the number of data points.

You may specify the length of each interpolated line segment in normalized coordinates by including a value with this keyword. The default value is 0.005 which is obtained when the parameter Spline is present. Smaller values for this parameter yield smoother lines, up to the resolution of the output device, at the expense of more computations.

Start_Level Keyword

Corresponding System Variable: !PDT.Start_Level

Specifies the initial level of tick labels to be displayed on a Date/Time axis. The subsequent levels depend on the data range and the first level selected.

Index Values for the Start_Level Keyword
Index	Start Level
7	Year
6	Quarter
5	Month
4	Week
3	Day
2	Hour
1	Minute
0	Second
-1	Auto-level

Subtitle Keyword

Corresponding System Variable: !P.Subtitle

Produces a subtitle underneath the x-axis containing the text in this string parameter.

Symsize Keyword

When used with PLOT, OPLOT, and PLOTS, the Symsize keyword can specify an array of symbol sizes. If an array is used, each plot symbol size in the array is applied, in order, to size the plot symbols that make up the graph. The symbol sizes are repeated, as needed, to complete the entire graph of the data set.

Specifies the size of the symbols drawn when Psym is set. The default size of 1.0 produces symbols approximately the same size as a character.

NOTE: You cannot specify an array of values for the !P.Psym system variable. The array of color values can only be used with the Psym keyword.

T3d Keyword

Corresponding System Variable: !P.T3d

NOTE: When the T3d keyword is in effect, the CONTOUR2 Fill keyword is disabled.

A keyword flag which, if present, indicates that the generalized

!P.T must contain a valid transformation matrix before the T3d keyword can be used. The matrix can be set by using the Save plotting keyword with the appropriate plotting routine.

If T3d is not present the user-supplied coordinates are simply scaled to screen coordinates. See the examples in the description of the Save plotting keyword.

A valid transformation matrix can be placed in !P.T in several ways:

Use the Save keyword to save the transformation matrix from an earlier graphics operation.
Establish a transformation matrix using the T3D user library procedure.
Set the value of !P.T directly.

Text_Axes Keyword

XYOUTS

Values of this keyword may range from 0 to 5, with the following effect: 0 for XY, 1 for XZ, 2 for YZ, 3 for YX, 4 for ZX, and 5 for ZY. The notation ZY means that the horizontal direction of the text lies in the Z plane, and the vertical direction of the text is drawn in the Y plane.

Specifies the plane of vector-drawn text when three-dimensional plotting is enabled. By default, text is drawn in the plane of the XY axes. The horizontal text direction is in the X plane, and the vertical text direction is in the Y plane.

Thick Keyword

Corresponding System Variable: !P.Thick

Controls the thickness of the lines connecting points. A thickness of 1.0 is normal, 2.0 is double-wide, etc.

Tickformat Keyword

Corresponding System Variable: !P.Tickformat

Lets you use FORTRAN-style format specifiers to change the format of tick labels on the x-, y-, and z-axes. For example:

PLOT, mydata, Tickformat = '(F5.2)'

The resulting plot's tick labels are formatted with a total width of five characters carried to two decimal places. As expected, the width field expands automatically to accommodate larger values. For more information on format specifiers, see Explicitly Formatted Input and Output in Chapter 8 of the

-WAVE User's Guide

Example 3: Specifying Tick Label Formats

User's Guide

Note that only the I (integer), F (floating-point), and E (scientific notation) format specifiers can be used with Tickformat. Also, you cannot place a quoted string inside a tick format. For example, ("", F5.2, "") is an invalid Tickformat specification.

Ticklen Keyword

Corresponding System Variable: !P.Ticklen

Controls the length of the axis tick marks, expressed as a fraction of the window size. The default value is 0.02. Ticklen of 0.5 produces a grid, while a negative Ticklen makes tick marks that extend outside the plot region, rather than inwards.

Example

To produce outward-going tick marks of the normal length:

PLOT, X, Y, Ticklen = -0.02

To provide a new default tick length, set the system variable !P.Ticklen.

Title Keyword

Corresponding System Variable: !P.Title

Produces a main title centered above the plot window.

The text size of this main title is larger than the other text by a factor of 1.25.

For example:

PLOT, X, Y, Title = 'Final Results'

Upper_Only Keyword

Indicates that only the upper surface of the object is to be drawn. By default, both surfaces are drawn.

Week_Boundary Keyword

Corresponding System Variable: !PDT.Week_Boundary

Sets the day of the week on which week tick marks are drawn for the week level on a Date/Time axis.

For example, if you set the week boundary to `Sunday', weekly tick marks are drawn for each Sunday and each one is labeled with the date.

Week Boundary Indices
Index	Day of Week
0	Sunday
1 (the default)	Monday
2	Tuesday
3	Wednesday
4	Thursday
5	Friday
6	Saturday

Width Keyword

MAP_XYOUTS

XYOUTS

For example, to put the width of a text string in the variable w_title, use:

Returns the width of the text string, in normalized coordinate units, to the designated variable.

XYOUTS, x, y, 'Title of Graph', Width = w_title

[XY]Axis Keyword

AXIS

The XAxis and YAxis keywords indicate which type of axis is to be drawn by the AXIS procedure and its placement.

[XYZ]Charsize Keyword

Corresponding System Variable: ![XYZ].Charsize

The size of the characters used to annotate the axis and its title.

This field is a scale factor applied to the global scale factor set by !P.Charsize or the keyword Charsize.

[XYZ]Gridstyle Keyword

Corresponding System Variable: ![XYZ].Gridstyle

Lets you change the linestyle of tick intervals on the x-, y-, and z-axes.

The default is a solid line.


Index	X Windows Style	Windows Style
0	Solid (default)	Solid (default)
1	Dotted	Short dashes
2	Dashed	Long dashes
3	Dash dot	Long-short dashes
4	Dash-dot-dot-dot	Long-short-short dashes
5	Long dashes	Long dashes

[XYZ]Margin Keyword

Corresponding System Variable: ![XYZ].Margin

A two-element array specifying the margin around the sides of the plot window, in units of character size. Default margins are 10 (left margin) and 3 (right margin) for the x-axis, 4 (bottom margin) and 2 (top margin) for the y-axis. For the z-axis the default margins are both 0.

[XYZ]Minor Keyword

Corresponding System Variable: ![XYZ].Minor

The number of minor tick intervals on the particular axis. If set to 0, the default, PV-WAVE automatically determines the number of minor ticks in each major tick mark interval. Setting this parameter to -1 suppresses the minor ticks, and setting it to a positive, nonzero number n produces n minor tick intervals, and n - 1 minor tick marks.

[XYZ]Range Keyword

Corresponding System Variable: ![XYZ].Range

The desired data range of the particular axis, a two-element vector. The first element is the axis minimum, and the second is the maximum. PV-WAVE will frequently round this range.

[XYZ]Style Keyword

Corresponding System Variable: ![XYZ].Style

Allows specification of axis options such as rounding of tick values and selection of a box axis. Each option is encoded in a bit. See the following table for details:

Axis Options
Bit	Value	Function
0	1	Exact. By default the end points of the axis are rounded in order to obtain even tick increments. Setting this bit inhibits rounding, making the axis fit the data range exactly.
1	2	Extend. If this bit is set, the axes are extended by 5% in each direction, leaving a border around the data.
2	4	None. If this bit is set, the axis and its text is not drawn.
3	8	No box. Normally, PLOT, CONTOUR, and CONTOUR2 draw a box style axis with the data window surrounded by axes. Setting this bit inhibits drawing the top or right axis.
4	16	Inhibits setting the y-axis minimum value to zero, when the data are all positive and nonzero. The keyword YNozero sets this bit temporarily.

NOTE: The ZStyle keyword has no effect in Date/Time plots.

[XYZ]Tickformat Keyword

Corresponding System Variable: ![XYZ].Tickformat

Lets you use FORTRAN-style format specifiers to change the format of tick labels for the particular axis. For example:

PLOT, mydata, XTickformat = '(F5.2)'

This keyword works basically the same way as the Tickformat keyword.

[XYZ]Ticklen Keyword

Corresponding System Variable: ![XYZ].Ticklen

Functions the same as the keyword Ticklen. [XYZ]Ticklen, however, can be applied to the particular axis. [XYZ]Ticklen supersedes the value of the Ticklen setting.

[XYZ]Tickname Keyword

Corresponding System Variable: ![XYZ].Tickname

A string array, of up to 30 elements, containing the annotation of each major tick mark.

If omitted, or if a given string element that contains the null string, PV-WAVE labels the tick mark with its value. To suppress the tick label, supply a string array of one-character-long blank strings. You can do this with the command:

REPLICATE(' ', N)

(Null strings cause PV-WAVE to number the tick mark with its value.) Note that if there are n tick mark intervals, there are n + 1 tick marks and labels.

[XYZ]Ticks Keyword

Corresponding System Variable: ![XYZ].Ticks

The number of major tick intervals to draw for the axis. If omitted PV-WAVE will select from three to six tick intervals. Setting this field to n, where n 0, produces exactly n tick intervals, and n + 1 tick marks.

[XYZ]Tickv Keyword

Corresponding System Variable: ![XYZ].Tickv

The data values for each tick mark, an array of up to 30 elements.

This keyword allows you to directly specify tick data values, producing graphs with non-linear tick marks. PV-WAVE scales the axis from the first tick value to the last, unless you directly specify a range. If you specify n tick intervals, you must specify n + 1 tick values.

[XYZ]Title Keyword

Corresponding System Variable: ![XYZ].Title

Places a title below the particular axis.

[XYZ]Type Keyword