Preferences

The Preferences... item in the Edit menu, brings up a dialog box in which one can set the default display behavior for new graphs. One can control the tick frequency, grid line colors, and scaling for graph axes; color, point styles, and line types for scatter plots; and colormaps and scaling of images. The window has a paned format in which the options affecting each part of the graph has a pane which can be brought forward by clicking the appropriately labeled tab.

• POW

  
       This pane sets the application level preferences for how POW
       looks and behaves.  Cursor sets the image to use as the
       mouse cursor when in POW's main window.  POW's "GUI" consists of
       the 3 pixel readouts, the Scopebox, and the Zoom In/Out buttons
       usually located at the top of the window.  The GUI
       Position option allows you to move these to any side of the
       window or turn them off altogether.  Scopebox Size alters
       the size of the scopebox -- the window showing a small overview
       of the current graph -- or hides it altogether.  Resize
       Window determines whether the POW window will get bigger or
       smaller (as far as possible) whenever you change the objects in
       the main POW window, so as to show you everything currently
       displayed in the main POW window without scrolling.
       Using the color grid or button, Background Color will set
       the color to use for the background of all of POW's windows.

• Graph

  
       This pane has been modified, containing a pair of entry
       boxes labeled Size, a set of buttons labeled
       Scaling and new control to choose functionality for
       right or left mouse buttons [More options are available when 
       editting a real graph (see Edit Graphs).]  Enter
       into the Size boxes, the default width and height to use
       when creating a new graph.  When a graph is created by another
       program (such as fv), it determines the size of the graph, so
       these options are usually overridden.  The Scaling buttons
       activate logarithmic graphs.  The first row of linear and
       log buttons cause each axis to be drawn in either linear
       or logarithmic format.  This does not affect the data, just how
       the graph coordinates are interpretted and labeled.  You can
       control the logarithmic conversion of individual curve data from
       the Points and Lines panes.
  
       The mouse control button can be clicked to switch the functionality
       of mouse buttons. Default will be left mouse button to control image
       zoom factor, and right mouse button to control brightness/contrast.

• Fonts

  
       This pane controls the appearance of text in the graph.  One can
       independently set the font, size, style, and color of the Title,
       Axis Labels, Tick Labels, and default Text Labels.
       The Text Label value is used only for the initial text label.  All
       subsequent labels inherit their values from the previous label.

• Ticks

  
       This pane controls the appearance of the tick marks and
       associated grid lines.  Use the slidebars to indicate
       approximately how many tick marks should be drawn (and labeled)
       on each axis of the graph.  At the far left, no tickmarks will be
       drawn on each axis.  At the far right, about 30 may be drawn.
       The X Ticks and Y Ticks options control whether the
       X and Y tickmarks are drawn inside or outside the graph's box and
       whether they are labeled on the left and bottom axes.  The
       Tick Labels option selects between Decimal and Base 60
       (degrees minutes seconds) numerical formats.  Base 60 is only used
       when a graph contains WCS information.  If the Grid Lines
       checkbox is selected, lines will drawn on the graph, tracing the
       path of each tick mark coordinate.  One can control the
       Color and line Style (solid, dashed, etc) of these
       lines.

• Points

  
       The checkbox at the top of this item indicates whether the
       individual points of the curve should be drawn.  The points can
       be drawn as any of the 7 listed shapes.  The size
       of the points (except Dot which is always 1 point) can either be
       fixed at a constant size indicated by the slidebar, or
       drawn with widths/heights indicating the X and Y error
       bars.  If there are X/Y error bars but the points are drawn
       in a fixed style, the error bars will be indicated by
       horizontal/vertical lines centered on the point.  Points can be
       Filled or just drawn in outline.  Finally, select the
       desired color from the displayed colorbar.  This can be a
       different color than selected in the Lines pane.
  
       At the bottom are a pair of LogX/logY checkbuttons labeled
       Transform (This is the same option as in the Lines pane).
       Checking these will cause curves to have the logarithm of their
       data plotted instead of the data itself.  This does not
       automatically result in logarithmic axes, which are turned on
       from the Graph pane.  Unless you will always want your data to be
       converted to a certain logarithm format, these options should be
       left unset.

• Lines

  
       The checkbox at the top of this pane indicates whether data
       points will be connected with a continuous line.  The line can be
       of several patterned styles or widths.  The points
       can also be connected directly (Normal) or in a
       stair-step pattern (Histogram).  In the latter mode, the
       Fill Boxes option draws the histogram as a series of solid
       boxes instead of an outline.  Finally, select the desired color
       from the displayed colorbar.  This can be a different color than
       selected in the Points pane.
  
       At the bottom are a pair of LogX/logY checkbuttons labeled
       Transform (This is the same option as in the Points pane).
       Checking these will cause curves to have the logarithm of their
       data plotted instead of the data itself.  This does not
       automatically result in logarithmic axes, which are turned on
       from the Graph pane.  Unless you will always want your data to be
       converted to a certain logarithm format, these options should be
       left unset.

• Image

  
       This pane controls the appearance of images.  Most of the pane
       consists of a bunch of different colormaps.  They are grouped in
       the same sequence as listed in the Color menu: smooth, continuous
       colormaps, followed by ramps, then the step functions.  The
       Invert option will reverse the order of the colormap when
       turned on.  The Scaling option controls how the colormap
       is applied to the image.  For Linear scaling, each
       colormap level corresponds to a constant intensity range in the
       image.  Square-Root scaling changes the mapping such that
       the intensity range covered by each color level increases as the
       square-root function, producing higher contrast at lower
       intesities.  Logarithmic scaling uses the logarithmic
       function for colormapping, giving even more contrast at low
       intensities than sqrt.  Histo Equalize scaling computes
       a histogram of the image and tries to distribute colors equally
       over the number of pixels.

Clicking the Reset button will revert the options to their values when the dialog box was initially opened, undoing any modifications. Clicking the Save button will make the current settings the defaults for new graphs and save them in your .powrc file. The Get Current button grabs any available options from the current graph. Its current image (if present) will be used for the default image options and its first curve (if present) for the default curve options. Exitting will also make the new settings the current defaults, but won't save them.