Purpose: discuss what a numeric vector is and why it is beneficial. [BLT] is a general extension with lots of useful things. One of the very interesting constructs is a new data type - a numeric vector. One reads in and creates a vector using a BLT C API. This allows you to bypass the overhead of reading large amounts of data into Tcl strings. The numeric vector is used by BLT for plotting, and thus one avoids some of the problems in trying to plot large amounts of points onto the Tk [canvas] widget. [RS]: Do I understand right that such a thing is like a [list], except limited to numbers, and possibly in length also? ---- [Category Graphics], [Category Mathematics]