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Subsections

AIPS View Panel


AIPS View Window Information Area

Below the menus, aipsview displays information about the data set including the filename, size in pixels, and axis information (both labels and the range in world coordinates).

Figure 2.2: AIPS View Window Information Subpanel
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View Axis Control

After the information area is a section labeled Slice which is used to control which axes are displayed and which one is to be used as the Z axis. The content of this subpanel varies depending on the number of axes of the data set.

If there are only two axes, the section has only a single button labeled: Show Image, see Fig. 2.3.

Figure 2.3: AIPS View Axis Control Subpanel for 2D data sets
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For data sets with more than two dimensions there will be a number of buttons. For a 3D image cube, there will be one button for each axis, see Fig. 2.4. Pressing one of these buttons opens a Display window showing the selected view of the data set. The labels on the buttons (obtained from the header of the data set) indicate which axis of the data set will serve as the Z axis for the view. The default is to display the middle plane in the Z dimension; in the case of an RA-DEC-VELO cube, this will be the middle velocity image. An exception is where the Z-axis is STOKES, in which case the first plane is displayed. To produce a RA vs. VELO slice, one would push the Slice: DEC button. Multiple representations (e.g. both an RA-DEC and an RA-VELO) may be displayed simultaneously.

Figure 2.4: AIPS View Axis Control Subpanel for 3D data sets
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When a data set has a dimensionality greater than three, aipsview attempts to find the first axis (after the first two) with more than one element. Also, in addition to the buttons for the first three axes (n.b, the third axis is the first axis, after the first two, with more than one element), there are buttons labeled Set Map, which are shown in the Slice: area of the AIPS View window. Choosing one of these Set Map buttons brings up a Slice Button Setup window that can be used to configure the view and change the button label from Set Map to one specified by the user. In Fig. 2.5 the first two Set Map buttons after the default RA, DEC, and VELO have been configured to select Stokes V and Stokes I, respectively; the remaining seven Set Map buttons remain to be configured.

Figure 2.5: AIPS View Axis Control Subpanel for data sets with more than 3 axes
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Slice Button Setup Window

Figure 2.6: Slice Button Setup Window
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The Slice Button Setup window contains the following controls:

Done
When this button is pressed, the window closes and any changes take effect. Once the window is closed, it can not be opened again unless the data set is closed.

Label
This displays what label the toggle button will have when the window is closed. If the file's rc file is updated (i.e., select Update file's rc from the File menu of the Display window, see Section 2.3.1), the button will have this label the next time aipsview is started.

Autodisplay
If this button is off (default), the image will not be automatically displayed when the window is closed. The user will have to press the slice toggle button again. If the button is turned on, aipsview will open the image when the window is closed.

The main part of the window consists of one row of toggles and sliders for each axis in the data set. To choose which axes to use as X, Y, and Z, simply press the appropriate button. In the example of Fig. 2.6, the display is set up for the X axis to be RA (axis number one), Y axis to be DEC (axis number two), and VELO (axis number four). Sliders are available to choose starting and ending indices for the X and Y axes. The Z axis slider chooses which plane along the Z axis to initially display. The slider for the other axes chooses where along the axis to retrieve the X-Y-Z data cube. If an axis has only one entry, there is no slider. The numerical input field is for use when the slider does not have enough resolution to choose exact value.

When a file's rc file is updated (see Section 2.3.1), aipsview remembers the settings made when the Slice Button Setup window was closed and the state of the slice toggle buttons (whether a view is being shown or not). These settings will be restored the next time aipsview is run.

Notes on the Slice Button Setup window:

  1. The number of toggles displayed can be changed by editing the configuration variable sliceControl,extraToggles. While the variable has no preset limit, setting this value to too high a value could make for an unwieldy sized control window.

  2. No extra toggles will be created if a data set has only two axes.

  3. Buttons that have been configured can not be reconfigured without editing the resource file or loading the data set again, which will start the AIPS View window with the extra slice buttons in their default state (i.e., Set Map).


Data Slider

A slider at the bottom of the AIPS View window allows the user to adjust the minimum and maximum data values to be displayed, both in the raster image in the Display window (see Section 2.4.5) and in the profile plot (see Section 2.4.4). If you cannot see your image in the Display window, try adjusting with the Data range slider. The button Set changes the minimum and maximum range of the slider to be the current slider settings; it is used to get finer control. The Reset button restores the minimum and maximum settings to those of the data set. It is also possible to change the values by editing them using the keyboard. Remember to press the <RETURN> (labeled <ENTER> on some keyboards) key after typing in each value. Note that if you increase the minimum and maximum range by typing in numbers, aipsview does not automatically change the slider to the new extreme values; you must manually manipulate the slider to obtain the desired range. When the user updates a file's rc file (see Section 2.3.1), aipsview saves the data clip min and max values.

Figure 2.7: AIPS View Data Slider Subpanel
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Blanked Data

Blanked FITS data are handled by aipsview in the following manner. Floating point values equal to NaN (Not a Number) or integer values equal to the value of the BLANK keyword in the FITS header are treated as blanked values. If the BLANK keyword is not set, integer files are not checked for blanked values. AIPS++ and MIRIAD masked data are treated as blanked. Pixel values corresponding to blanked values are displayed as black. With the default colormap and the initial data range, any black in the image will be blanked data. Changing the colormap will not change the color of blanked pixels (unless you have told aipsview to use the entire colormap, via: an environment variable, Appendix A.1.1, an X-defaults file Appendix A.1.2, or a command line switch, Appendix A.1.3). When the profile is displayed (see Section 2.4.4) and a blanked pixel is present, nothing is plotted for the blanked intensity so that a gap is displayed in the profile plot.

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Next: Display Window Menus Up: Using Aipsview Previous: AIPS View Window Menus   Contents