| FILE menu
The program can have up to 20 data files open simultaneously, each in its own window. You can switch between files either by clicking the appropriate window, or with the WINDOW menu. Individual files can be closed either by clicking the standard 'close' button, or if the window of the file you want to close is active (in front), with the close file option in the FILE menu.
If you have the maximum number files open and attempt to load another, you will be asked which of the currently open files you want to close to make room for the new file.
For any file format, you can automatically scan and fix large ‘spikes’ in the data by selecting the ‘Automatically Filter Newly-loaded Files’ option in the PREFERENCES/FileHandling menu.
The file opening box highlights only these types, with the proper extensions. Two are binary formats, for LabHelper and edited LabAnalyst files: the older Binary-Coded Decimal (BCD) and Floating-Point (FP). LabAnalyst will transparently read either, but will write only in FP format. The main difference is speed: BCD files load more slowly (since they are read and converted one sample at a time), while FP files load quickly (since entire channels are read directly from disk into memory).
If you click the toolbar 'Open' or 'Append' or 'Stack' buttons, you will get this window if you've not specified in the 'Preferences' window that only Warthog files will be shown:
This gives you the choice of Warthog (current OS X files or 'classic' files obtained on earlier Mac OS versions [OS8, OS9, etc]), ASCII (text) or Sable SSCF or ExpeData files (see below).
Two of the buttons ('Warthog Only') and ('Sable or Warthog Binary') will only access files with the correct extensions (.whog, .whsc, .WHdata, .ext, .sabl, .WHsable). The 'Any Sable or Warthog File' button allows access to all file types, but only files in Warthog or Sable format will load properly. If you attempt to load a file that isn't Warthog or Sable format, you'll get an error message.
WARTHOG BINARY FROM 'CLASSIC' OS9... For old Warthog binary files from prior to OS X. WARNING: only files with these formats will load properly.
Note: binary files from 'Classic' Macs (OS8, OS9) may look like this:
You can make the correct icons appear by adding the appropriate file extension (e.g., '.whog' ).
TEXT [ .csv, ASCII ] FILE... This routine lets you load data in text (.csv) files, as long as:
Go to this page for more information on importing text files.
- data are in spreadsheet format with variables (columns) delimited by commas or tabs (spaces do not work as delimiters) and cases (rows) delimited by carriage returns
- the data are numeric only (text data are ignored)
- the input file may contain many variables but you must select a maximum of 40.
- NOTE: this will NOT import complex Excel worksheets (i.e., .xls; .xlsx). If you want to load data in Excel format into LabAnalyst, save a copy as a tab-delimited text file (.txt) or .csv file, which LabAnalyst can read.
SABLE FILE... Loads Sable Systems data files in SSCF format or the similar but newer 'ExpeData' format. Nearly all Sable files will load; those which have more than 40 variables will load the first 40 only. The maximum number of markers in LabAnalyst is about 20,000; Sable files can (theoretically; extremely rarely in practice) exceed that limit. The converter will read the first 20,000 markers only. Older SSCF files do not include channel labels, so after the completion of file loading you are prompted to provide your own labels. Also, the values for mass, flow rate, effective volume, and so forth are arbitrary and may have to be edited, and there is no information on voltage conversions. The newer ExpeData files contain channel labels and many conversion factors.
If you save Sable files from LabAnalyst or LabHelper, they will appear (on a Mac) with a custom icon (extension .WHSable):
Back to top
SABLE FILE... Merges a Warthog-format file (either text or binary) or a Sable SSCF file with the currently loaded file. The new file can either be appended to the 'right' (i.e., adding new cases) of the current file, or stacked to the 'bottom' (i.e., adding new channels).
Appending is much more common than adding channels. In either case, the following window opens (appearance will vary depending on the number of channels and samples in the two files):
The program checks to make sure the merged file will not exceed the current maximum file size -- unlikely unless one or both of the files are very large (a warning is shown if this is the case). However, the program does not check to make sure the channel contents match in the current and new files. Thus it is possible to create a new file that contains two (or more) types of data in a single channel (i.e., a set of temperature data from the initial file, then gas concentration data from a second file, then wind speed data from a third file, etc.).
Needless to say, this can cause considerable confusion unless you are careful to avoid merging files with differing channel types. To help avoid such mistakes, the computer provides a graphical display of the old and new data. In this example, the file to be merged has 8 channels and the current file contains 9 channels.
LabAnalyst will allow access to the maximum number of channels in either the current or new file. Sable SSCF files don't contain channel labels, so if you merge them you HAVE to know ahead of time what the channel structure is.
• If the new rate is “faster” than the old rate (i.e., more samples per unit time), LabAnalyst will add the extra data points by interpolation. For a simple example, if the original sample rate was one Hz (one sample per second) and you want to change that to two Hz (two samples per second), the program will fit one additional data point between each of two successive existing points. The new point will have a value that is the mean of the two points surrounding it. The operation is similar, but more complex, if the new and old sample rates are not integral multiples of each other.These operations are transient unless you save the file (or use the ‘Save as’ option to make a copy with a different name). But if you save a time-adjusted file under its original name, the file is permanently changed. You cannot ‘undo’ time adjustment. The time scale adjustment window looks like this:
As mentioned earlier, don’t make the mistake of thinking that because you have added more data points, you somehow have added information content.
• If the new rate is “slower” than the old rate (i.e., fewer samples per unit time), LabAnalyst will simply remove data points as appropriate. It does not do any averaging. Consequently, this operation reduces the amount of information in the file…. so use with care (and backup copies if you are wise).
Back to top
After a file is loaded, the 'plot area' in the top part of the screen displays either the first channel of the file (single channel mode) or several user-selected channels (multi-channel mode); see the VIEW menu for details. The screen in single-channel mode looks approximately as shown below -- but note that immediately after loading, no block will be selected and no data will appear in the results or block windows. The colors of the plot area and block window are user-selectable (VIEW menu) and may differ from this example.
Note that in current versions, a small gray band between the data bar and the plot area shows marker labels (this doesn't appear in the image above).
The appearance of the plot area depends on the screenwidth (the width of the screen in pixels) and the number of cases. If the file contains <= screenwidth cases, data are plotted 1 pixel per case (if the number of cases is < 50% of screenwidth, the plot is expanded, with more than 1 pixel per case). If the total number of cases is more than screenwidth, the X-axis will be scaled to fit within the screen dimensions. 'Screens' (consisting of screenwidth cases) are indicated by vertical lines, with a crossbar at the top of the active screen. The example shows a file containing many screenwidths of data.
If there are more than screenwidth cases, the bottom of the plot area will show a screen selection slider. The currently 'active' segment of the file -- the active screen - is indicated by the slider position. Use the slider or the left and right arrow keys to change the active screen. To view the active screen only (necessary for some manipulation and analysis operations), hit the shift or return keys. Do this again to go back to viewing the entire file (this example shows 'entire file' mode). Any markers are shown as vertical dashed lines (this file contains numerous markers, but they are not shown; see the VIEW menu). While in the plot area, the cursor is a cross-hair; out of the area it is an arrow. The data bar has a readout of case number, elapsed time, and the value of the currently active channel at the cursor position. The time of day is shown (24-hour scale) along the bottom of the plot area, with optional hour indicators (vertical dotted lines).
To perform analyses and some transformations, you need to select a data
block. This can be done by the normal 'click-hold-and-drag'
method (the cursor must be within the plot area). A second method
uses individual clicks: move the cursor to the desired start point and
click once; repeat for the end point (which may be on either side
of the start point). Alternately, blocks of defined width can be selected
with single clicks (see the BLOCK
WIDTH option in the ANALYZE
menu). If there is sufficient space, you can 'shift' blocks to the left or right with the BLOCK
SHIFT commands (also in the ANALYZE
You can select blocks in 'entire file' or in 'active screen only' mode, and blocks can include multiple screens. If a single screen is shown, mark the start with a single click, then shift screens until the end can be marked. A selected block is indicated as a color-inverted rectangle in the plot area, and is scaled to fit within the block window (discrete data points on the block window only appear if the number of included points is small).
Back to top
| Note for file saving options: |
When you save a file in either Sable or Warthog binary format, with either the Save... or Save As... options, LabAnalyst will add a file extension ( .WHdata for Save...; .WHSable if you select Sable-format output in the Save As... option). The new extension will replace any existing extension, which in effect creates a new file if the source file had a different extension (e.g, .whsc, .whog, .sabl, .ext) or no extension.
If you select the ASCII option, you have two formatting choices:
The 'Conditional save' option lets you filter data case by case and save only the cases that meet the selection conditions. You need to specify which channel is to be tested (it is not necessary that the tested channel will be saved), one of five Boolean criteria (<, =<, =, >=, >), and a selection criterion (a number against which the individual case values in the tested channel are compared).
In this example, only cases where the value of channel 13 (wheel#1 speed in RPM) is greater than 0.5 will be saved.
Data files (other than ASCII) that have been saved by LabAnalyst have these icons:
binary files (.WHdata)
Warthog text files
Sable formats (.WHSable)
LabAnalyst saves some other file types, shown here (these may look different on your system, depending on what version of OS X is running):
Preference files (.LApr)
Script files (.LAscript)
Note that a file loaded in Sable or ASCII format may not show all of the variables.
The following example shows the file data for a 13 channel file.
Most conversion equations used by the Warthog acquisition program LabHelper are 2-order polynomials (shown as "poly" in the transform column):
value = A + B*volts + C*volts2
Note that a C of zero produces a linear conversion. Occasionally a power function is used:
value = A + B*voltsC
Note that in a power function a non-integer C will produce meaningless data if the voltage is negative; in this condition, LabHelper sets the results to zero. A C value of 1 produces a linear conversion.
LabHelper allows use of the keyboard as an event recorder, and a single channel can use a 3-degree polynomial conversion. If data have been transformed or copied into a new channel, no coefficients are shown.
Back to top
Before printing, you are presented with 'Page Setup' boxes for whatever printer driver is in use. Note that for 'US LETTER' (or similar) sized paper, you should use landscape mode (maximum image sizes are about 70% for portrait mode and 80% for landscape mode). If you use other paper sizes, the recommended image sizes may be too large to fit on the page or smaller than the available space.
The printed output will match whatever is shown in the on-screen viewing mode (Entire File or Active Screen). A file displayed in the "Compacted and Averaged" format will be printed in that format. If a block has been selected, you have the option of printing only the block.
You can select which features will appear in the printout, such as labeling, file information, comments, and markers. If the file has more than one channel, you can print any subset of the channels.
If you click the 'non-standard plot heights' button, a window will open to allow customization of the height of each printed channel:
The window contains a diagram of the printed page. You select the relative height of each channel in sequence by moving the cursor on the diagram to the desired height, and then clicking the mouse ONCE. The channels will be redrawn one by one as their heights are selected. Note that there is a fixed amount of room on the page, so that enlarging one channel requires shrinking one or more of the others. Consequently, the computer reserves an amount of space necessary for plotting the remaining channels at the minimum possible height (and will not let you exceed that limit). You must select plot heights for all the channels. When done, you can accept the results, redo the plot height selection, or revert to the normal setting (all channels plotted with equal heights).
FILE IMAGE PREVIEW... like the above routine, but it sends the image to the screen instead of directly to the printer (you can re-route the previewed image to the printer).
Back to top
SPREADSHEET... Opens a spreadsheet-format text file for storing results generated by analysis menu operations. Data are saved in a tab-delineated format readable by many spreadsheet programs or statistical packages. Optionally, you can save results to an Excel-format file (double-clickable directly into Excel). Besides the results data, the spreadsheet file also contains column labels. Mean, SD, N, and variable name are always saved; other parameters (start of block, end of block, start and end time, elapsed time, analysis type, mass, and channel number and file name) are user-selectable. You can also enter one or two user-typed 'notes' with each case (edit fields appear in a window over the COMMENTS window when the 'p' key is struck; hit 'return' or click the window close button when the values are correct). Certain analyses, such as regressions, do not fit this format and cannot be put into spreadsheets.
The default is one set of analysis results per line in the spreadsheet, but if you've selected Excel format you can use the 'Multiple results per line' option to save the results from two to 15 different analyses per line. You need to specify how many results you want to save initially (you can't change this when the file is in use). Therefore, you need to keep track of the order of analyses so as to avoid confusion later on. If you use notes or store animal mass, these items are saved only once per spreadsheet line (not every time you save an analysis result).
Here is a general format for one line from a file with 2 results per line, with both user notes selected and mass saved:
Note1 · Note2 · M1 · SD1 · N1 · var1 · anal1 · mass · M2 · SD2 · N2 · var2 · anal2 <CR>
where · is a tab character, <CR> is a carriage return character, M1 = mean of the first result, SD1 = SD of first result, N1 = sample size of first result, var1 = variable for first result, anal1 = analysis for first result, mass = body mass, M2 = mean of the second result, etc.
Storage of results (in memory) occurs when you press the 'p' key (with the Results window open), or select OUTPUT RESULTS. The spreadsheet file is not saved to disk until you exit from LabAnalyst or use the PRINT | CLOSE FILE option.
Some additional considerations:
SIMPLE TEXT FILE... Opens a text file for storing the contents of the Results Window. The format of the disk file is similar to that shown in the Results Window and is identical to the format of data sent to the printer. These files are not formatted for use in spreadsheet-based applications, such as Excel.
Real storage (writing data to disk) occurs when you select the PRINT | CLOSE FILE ( J ) option. However, any temporary memory tables are automatically saved to disk if you quit the program.
Back to top