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Using McIDAS-V FAQ

Q. What do I do if McIDAS-V will not work on my computer?

A. Listed below is a basic checklist of steps to follow if your McIDAS-V is not working properly. Once you successfully complete each step in the process, restart McIDAS-V and try again. If the problem still exists, proceed to the next step, and so on.
  1. Make sure that your drivers are up to date. Please see the Graphics Cards and Drivers section of the System Requirements page for more information.
  2. Try downloading this Java3D example to see if you can view it. Please see the Java Versions section of the System Requirements page for more information. If this example does not work, then your system does not support Java3D.
    Note: If your system does not support Java3D version 1.3.1+ McIDAS-V will not work for you.
  3. Set a small heap size by setting the Memory option to 512 megabytes in the User Preferences window's Advanced tab. If this resolves the issue, you can start increasing the memory until the problem appears again. Stay below the memory value that produces the problem.
  4. Disable Java Access to Image Data by Reference by unchecking Enable access to image data by reference option in the User Preferences window's Advanced tab.
  5. If you are on a Windows computer, use Direct3D by checking the Enable Direct3D option in the User Preferences window's Advanced tab.
  6. Rename your McIDAS-V document directory to start with a clean set of options. This will undo the changes made in steps 3-5 listed above, but it will eliminate any corrupt startup bundles or settings.
  7. Repeat steps 3-5 with a clean slate.

Q. Where are the McIDAS-V files stored on my computer?

A. McIDAS-V files are divided into two categories: "system files" (supplied files that should not be edited) and "user files" (new user-created files and supplied ones that contain user settings and preferences). By default, the system files are stored in a directory named McIDAS-V-System, and the user files are stored in a directory named McIDAS-V. The system file directory can be changed during installation and its location defaults to the OS application directory (e.g., C:\Program Files on Windows, /Applications on OS X). The user file directory is created in the user's document directory (e.g., C:\Documents and Settings\user\ on Windows, /Users/user/Documents on OS X, /home/user on Linux).

Q. How can I tell if McIDAS-V is busy doing something?

A. The lower right corner of the Main Display window shows a box with progress bars if McIDAS-V is busy making a display or doing anything. In the status bar at the bottom, messages will appear when McIDAS-V is reading data from a server or disk. Also, while the displays are being created, there is usually a "please wait" notice in the lower left corner of the main display. When McIDAS-V is in the middle of a process in the Data Explorer window, the cursor will change to a spinning, blue ring.

Q. How can I save a display?

A. McIDAS-V supports JPEG, PNG, and GIF image formats. McIDAS-V can also write out an image and the corresponding Google Earth KML or KMZ files. Animations can be captured as QuickTime movies or animated GIFs. See Image Captures for more information. You can save a particular McIDAS-V state with all displays, data sources, maps, etc. by saving the data as a bundle. You can also save a bundle as a favorite.

Q. How can I change the start-up settings?

A. You can customize many of the McIDAS-V properties through the User Preferences window, accessed through the Edit->Preferences menu item in the Main Display window. This allows you to configure the many features of McIDAS-V.

You can set a bundle to open by default when you start McIDAS-V. To do this, save a bundle as a favorite and set it as your default bundle in the Defaults panel of the Advanced tab of the User Preferences window.

You can also set the locations of the Main Display window and the Data Explorer window, as well as the number of tabs and panels. To do this, save a default layout via the File->Default Layout menu item in the Main Display window.

Q. How can I change the amount of memory available to McIDAS-V?

A. You can change the amount of memory used by McIDAS-V by editing the Memory in the Advanced tab of the User Preferences window by selecting Edit->Preferences... from the Main Display window. See Running McIDAS-V for more information.

Q. How can I reset the map projections?

A. This can be controlled with the Projections->Auto-set Projection menu check-box. You can switch an existing display to its native data set projection using the display control's View->Use Data Projection menu.

Q. How can I set the default projection?

A. The default map projection can be set with the Projection Manager which is accessed from the Projections->New/Edit menu item in the Main Display window. Also, you can select one of the predefined maps in the Projections menu. The default projection is overridden by the projection saved in the default bundle, or by displaying new data, if the Projections->Auto-Set Projection menu checkbox is checked on. As a result, you may never see the default map projection unless your default bundle has the default projection, and you have the checkbox checked off. Choosing a default map projection is not necessary for good use of McIDAS-V and you can ignore it if you like. It is often simpler to use default bundles.

Q. How can I change the color table range of a displayed parameter?

A. You can change the range for a display parameter in the Color Table Editor. This can be accessed in the Layer Controls tab of the Data Explorer by clicking the button next to Color Table, or by right-clicking on the color bar in the Legend of the Main Display window and selecting Edit Color Table. The range of the color table can be changed next to the Range button in the Color Table Editor. Alternatively, you can change the range outside of the Color Table Editor by right clicking on the color bar in the Legend of the Main Display window and selecting Change Range..., which opens a Change Range window where you can enter new values.

Q. When I set a color table transparent, why doesn't it show up that way?

A. Using transparency in a color display may give unexpected results. In general, only the last thing added can be fully transparent. If you have a display that is transparent, then add in a new display, you may not see it. You can use the display control's View->Bring to Front menu to remove and re-add the display that you want to be transparent so it is last.

Q. When I load an image, why is it displayed with fewer colors than I expect?

A. First, check that your display configuration is set to the maximum number of colors (e.g., 32 bit) so that McIDAS-V is able to display imagery and color tables using a full range of colors. If that is set correctly, it's possible that the range of values defined for the color table is less than the range of values in the displayed image. You can view or modify the range of values defined for the color table by right clicking on the color bar in the Legend of the Main Display window and selecting either Change Range... or Edit Color Table. Right clicking also displays other options that let you apply a different color table or edit the current one.

Q. When I load an image, why does it appear pixelated (blocky)?

A. A displayed image can appear pixelated (blocky) due to one or more factors, including the resolution of the displayed image, the magnification and pixel sampling factors at which it was displayed, and the zoom factor.

For example, if you display an 8 km resolution image while zoomed in to a small geographic region such that each display pixel represents a higher resolution value (e.g., 1 km2 of the earth surface) the image pixels need to be duplicated to fill the display and thus the image will appear pixelated. The same effect will occur with any image if you zoom in (using the Zoom/Pan Toolbar buttons or other zooming actions) to where the display resolution is higher than the image resolution.

If you believe that the displayed image is more pixelated than it should be for its given resolution, check the settings of the Magnification sliders in the Field Selector's Advanced tab and the Pixel Sampling slider in the Layer Controls tab. In order to display the image at the highest possible resolution (its native resolution), the line and element magnifications must be set to 1 (sliders all the way to the right) and the pixel sampling set to 0 (slider all the way to the left).


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