PROC GPLOT

1
PROC GPLOT

• GPLOT is used to make two dimensional
  scatter-plots.
• General Syntax
• proc gplot datadata-set options
• plot y-variablex-variable/options
• run
• quit

2
Multiple Plot Calls in a Plot Statement

• Multiple y-variablex-variable calls are
  permitted in a plot statement, each generating a
  separate plot by default.
• In the PROC GPLOT statement the uniform option
  gives each plot the same axis scales.
• Assuming a common x-variable, the overlay option
  (in the plot statement) will cause the plots to
  be displayed on the same graph.
• A legend is created for overlay plots if the
  legendlegendn option is included.

3
Multiple Plot Calls in a Plot Statement

• proc gplot datasave.padgett
• plot totmassplantht
• /now do more than one plot at a time/
• proc gplot datasave.padgett
• plot totmassplantht bllenavgplantht
• /we get two different plot/

4
PLOT and PLOT2

• The PLOT2 statement allows for a second vertical
  axis to be displayed. Conditions
• The x-variables in PLOT and PLOT2 must be the
  same.
• Differing vaxis specifications can be made for
  each.

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PLOT and PLOT2

• /to get two different y-axes, try this/
• proc gplot datasave.padgett
• plot lleavesplantht /left/
• plot2 bllenavgplantht/right/
• /we get two plots on the same horizontal axis,
  but two different y-axes/

6
Plots According to Third Variable

• Plots of the form y-variablex-variablez-variable
  produces a plot for each level of the
  z-variable.
• Overlaying of plots is automatic.
• A legend is produced automatically.
• This legend can be modified in a similar manner
  to that of legends in bar charts.

7
Plots According to Third Variable

• proc gplot datasave.padgett
• plot totmassplanthtmarsh/legendlegend1
• /distinguishes the plotting points by marsh and
  produces a legend so we can tell which is
  which/
• / modify the legend as below /
• legend1 down2 position(top left inside)
• frame cborderblue cframegray cshadowred

8
LEGEND Statement Options

• acrossn Legend is created with n entries per
  row.
• downn Legend is created with n entries per
  column
• Only one of ACROSS or DOWN should be specified.

9
LEGEND Statement Options

• position(P1 P2 P3) Legend is positioned based
  on parameters specified.
• Bottom, middle or top Sets vertical position.
• Left, center or right Sets horizontal position.
• Inside or outside Places legend inside or
  outside the graph area.
• Default is (bottom center outside).

10
LEGEND Statement Options

• modereserveprotectshare Controls how space
  is allocated to the plot and the legend.
• Reserve Legend is allocated its own space in
  the output area. This is the default however,
  it cannot be used for position (inside).
• Protect The legend is protected from the
  plotit is drawn over the plot. This is the
  default when position (inside).
• Share Graphics are drawn over the legend if
  there is any intersection.

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LEGEND Statement Options

• frameDraws a frame around the legend in the
  first default color.
• cborder Draws a frame around the legend in the
  specified color.
• cframe Specifies the background color of the
  legend (or fills the frame).
• cshadow Places a shadow behind the legend in
  the specified color.

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LEGEND Statement Options

• shape Controls appearance of the legend
  symbols. Specifications include
• bar(width, height)
• line(length)
• symbol(width, height)
• label(text-attributes text ) Defines the
  legend label text.
• value(text-attributes-n text-n ) Defines the
  text associated with each legend symbol.

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LEGEND Statement Options

• Text attribute options include
• c Text color.
• f Text font.
• h Text height.
• t (value option only) Legend entry to be
  modified. Must precede the attributes being
  changed for that entry.
• position (label option only) Positions legend
  label. Same options as legend position except
  for inside/outside (legend label is always
  inside).

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Axis Modification

• As an option in the plot statement (after the / )
  the user can specify haxisaxisn and/or
  vaxisaxisn to associate each axis with an axis
  statement.
• A plot2 statement may include a vaxisaxisn
  specification as well.

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Axis Modification

• proc gplot datasave.projects
• plot equipmntjobtotal/legendlegend1
• haxisaxis1 vaxisaxis2
• where stname in (NC SC VA)
• legend1 down2 position(top left inside)
• frame cborderblue cframegray cshadowred
• axis1 label(Equipment Cost cblue
• h2 fswissb) minornone
• axis2 label(Total Costs)

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The AXIS Statement

• Axis statement options include
• c (color) Specifies the color of the axis
  lines, tick marks and text.
• width Specifies the thickness of the axis
  line.
• order(value list or start to stop by increment)
  Specifies the data values corresponding to the
  major tick marks.
• offset(n1,n2) Specifies the space from the
  start of the axis to the first tick and the end
  of the axis from the last tick, respectively.

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The AXIS Statement

• Axis statement options include
• label(text-options text) or NONE Defines
  the axis label and its attributes.
• value(text-options-n text-n) or NONE
  Defines major tick labels and attributes. Can
  be done as a group or one at a time.

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The AXIS Statement

• Attributes that can be specified within the
  label and value options
• c Text color.
• f Text font.
• h Text height.
• a Angle of the text string.
• r Rotation of individual characters.
• t (value option only) Tick mark to be
  modified. Must precede the attributes being
  changed for that tick.

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Enhancing the Plot Area

• The SYMBOL statement
• Modifies the plotting symbol and related items
• symboln options
• n can range from 1 to 255.
• If n is omitted it is taken as 1 by default.
• SYMBOL statements are globalremain in effect
  until altered.
• They are applied across the current color list if
  no color is specified.

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Some SYMBOL Statement Options

• v (value) Specifies the plotting symbol.
• f (font) Specifies the font from which the
  plotting symbol is selected.
• cv Symbol color.
• h (height) Specifies the height of the
  symbol in cells.
• pointlabel places y-value near each point

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Inheritance in SYMBOL Statements

• SYMBOL statements are global, some behaviors
• Unmodified options will be inherited in
  subsequent definitions of a symbol statement.
• Modifications to a symbol statement (e.g.
  symbol2) does not alter symbol statements with
  other numbers.
• The statement goptions resetsymbol cancels all
  currently defined symbol statements.

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Symbols

• Default symbol specifications and results

23
Symbols

• Write 3 symbol statements to change the colors,
  shapes,sizes of the 3 plotting symbols for NC,
  SC and VA
• Go back to Padgett data and experiment with
  symbol statements

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The GFONT Procedure

• You can view a SAS/GRAPH font using PROC GFONT.
  The typical syntax will be
• proc gfont namefont nobuild showroman
  ctextcolor
• run
• This code will display the font symbols with
  their standard counterparts. Fonts can be found
  in the fonts catalog in the SAShelp library.

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Plot Lines

• i (interpol) Specifies the interpolation
  method. Some of these include
• join Joins the points with line segments
  (connect the dots).
• sm Draws a smooth curve through the points,
  is a number that determines the level of
  smoothness (highersmoother).
• needle Draws vertical lines from the data to 0
  (or the minimum value if all are greater than 0).

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Plot Lines

• Rlttypegtlt0gtltCLM or CLIltgtgt where
• type is L, Q or C corresponding to linear,
  quadratic or cubic regression, respectively.
• 0 forces the regression through the origin.
• CLM and CLI specifies display of confidence
  limits for average (mean) predicted values and
  individual predictions.
• specifies the confidence level between 50 and
  99.

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Plot Lines

• The SYMBOL statement can be used to control plot
  lines
• l (line) Specifies a line type (various types
  of dashed lines). Valid values go from 1 to
  46.
• w (width) Specifies the line thickness.
• ci Sets the line color.
• c (color) Sets colors for both lines and
  symbols.

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Plot Lines

• Now try your hand at some of the interpolation
  methods - see if you can find the best smoothing
  for total mass against plantht by marsh in the
  Padgett data