How to do a real time graph
On 27 April 2009 at 12:58, Krishna Dagli wrote:
| I have a simple application that reads a pipe delimited line (price and time) | from a network; over a socket and I want to plot the movement of same | in real time using a graph. | | What packages / approach should I take? R is not really set up for that. It is neither meant for real-time work, nor does it incremental plotting all that well. It can be done, but not well. In the narrow sense, you need to read the documentation about R socket connections, and about plot() and maybe some of the time-series classes (zoo, xts, ...) and then just do it. Two things I have used and am using are - kst (kst.kde.org) which can handle enormous amounts of data (coming from astrophysics) really efficiently where you only have to write out a txt file from which kst reads---that sounds odd, but you keep a cache of the data outside your app that way which is nice; your existing listener writes the text file, you only need to parameterise kst and don't need to write code for it - do-it-yourself where I use C++ and the qwt plotting widget library (from sourceforge) on top of Qt (www.qtsoftware.com) along with a few lines of C++ code---this works great for transformations (spreads, ratios, ...) too. But there surely are a number of other choices. Dirk
Three out of two people have difficulties with fractions.