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.
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.
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.
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.
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.
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.
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.
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.