Frequently Asked Questions and Tips



How can I annotate a frame?

Currently there can be one line of text data associated with each frame, defined via the formula, by passing a text argument to the Frame[] function. The argument value can be either a double-quoted string, or a Read_text[] expression.

From the command line the options -tf, -to, and -tl can be used to automatically establish Read_text[] calls in formulas. Other command line options can set text position (-t), text color (-T), and text style (-ts), font name (-fn) and font size (-fs).

Once a SpreadSheet session is saved in a header file, the header file may be edited to change text display parameters:

Global settings include:

Settings variable for each frame include:

How can I read many files with a common prefix or suffix?

The SpreadSheet allows the use of file patterns involving the special symbols '#' and '[...]', to refer to a set of files. The pound sign (#) will expand to any integer or decimal number, and will sort the matching files into increasing numerical order e.g. a# may return a1, a1.2, a02, a005, etc. The brackets ([..]) can enclose two or three strings, separated by commas, good for stereo pairs or R,G,B images e.g. hugo.[left,right] expands to hugo.left and hugo.right. Also im.[r,g,b] expands to im.r, im.g, im.b . The ([..]) and (#) notations can be used in the same file pattern, provided the (#) is not inside the brackets. When using the pattern notation on the command line, escape the special symbols so that the shell does not interpret them, or enclose the expressions in double quotes to accomplish this e.g. hugo.\[left,right\] or "hugo.[left,right]" . The special symbols do not need to be escaped when typed into the File Pattern field on the Read Panel.

How can I change the overlay color, text color, font size, etc. ?

These all fall under the category of items which can be changed by manually editing a header file. (Changing these things cannot yet be done via the IISS user interface.)

Header file parameters which can be changed include:

index, # null index is an offset into the main colormap
index, # vacant index is an offset into the main colormap
index, # error index is an offset into the main colormap
index, # one_channel index is an offset into the main colormap
rrggbb, # three_channel rrggbb is the catenation of 3 hex numbers, standing for red, green and blue intensities )




Can I change the cell dimensions?

The formal program interface does not yet allow for changing cell dimensions after the start of a new session (see Chapter 8 for the command line option -w). However you can change the cell dimensions stored in a header file, provided you ensure that each cell in a given row has the same height, and each cell in a given column has the same width. So for example, if you change the dimensions of cell B3 to 300 x 350 which in the header file would be: dims(300,350), make sure that all cells in row B are changed to a height of 350 and all cells in column 3 are changed to be of width 300. Finally, after reading in the header file, click on one of the cells in the matrix glyph on the Options Panel to reset the view shown in the IISS.

Hints on using FORMS

To type into a text input field, click a mouse button in the field to activate it, and keep the mouse somewhere in the form while typing. Use the left and right arrow keys to position the I-beam cursor in a text-input field. To erase an active text input field, hit the Esc key. In a form with several text input fields, hit Tab to activate the next field in sequence. A multiline input field (such as that in the Formula panel) may contain text which is too far down or to the right; we are working to alleviate this problem. If a button displays a carriage return arrow then pressing the Return or Enter key will activate it. In the file selector, click on the directory listing to edit it, click on the search pattern to edit it, and click in the browser to enter a file name in the corresponding field. A pull-down menu which lists the current selection as the menu title is a "choice" object; clicking on it with the left mouse button steps forward one choice, and using the middle button steps backward by one choice.