C-PLOT

Scientific Graphics and Data Analysis

3.2.16. - Options +Dskip, =Dtotal, &, . and @



The +skip and =total options let you select particular windows of data from your file. They also can be used to read in sections of a file for editing under mode 7. Skip is an integer telling the program how many lines in a file to skip before starting to read in data points. When skipping lines, each line in the file is counted, whether it contains valid data or not. Total specifies the maximum number of points to be read from the file.

The & argument causes the data points being obtained to be appended to the current data points.

The @ argument specifies real-time plotting. When you plot the points, C-PLOT will first draw any data already in a file. It will then continue to check the file to see if more points have been added, plotting them as they appear. If the end-of-file character ( ASCII \004) or a ^D are read from the file after a newline, the program stops reading the file and proceeds to the next command (if running from a command file) or to the PLOT-> prompt (if running interactively.) You also can use a ^C to interrupt the reading. In the present implementation, the program sleeps for one second between checks for new data.

The optional arguments +skip , =total , & and @ are typed after the file name and separated from the file name by space.

Entering gd . tells C-PLOT to get data using the same mode and file name as before. For the modes with specified columns (3, 5, 8 and 12), you will still be prompted for column numbers. You can use . to keep the same file name when switching to a different mode. After entering gd 2 filename, for example, you can enter gd 3 . to indicate you want to use the same file, but this time you want to specify the columns.

You can use the +skip , =total , & and @ options with the . option. For instance, gd . +1024 will begin reading at the 1025th line in the current data file. If you followed that with just gd ., the first points in the file will be read.

The . option does not repeat modes 6, 7, 10 or 15.