Hi there,

I'm pretty new to python (am an embedded C programmer by trade), but I have 
a need to be able to plot data being written to a CSV file and show the 
plot in pseudo-real time in pyqtgraph.

I have built the GUI with the plots and am happy with it plotting static 
data and rolling round (it reads data from a CSV file once using pandas) 
but I'm having trouble getting pandas to work for real time data that is 
being written to the CSV file by another process once a second.

I am wondering if pandas are the right way to go for this? Once a second my 
CSV file will be written to, it has a variable data rate of either 1,16,32 
or 128Hz and each sample (on a new line) contains a timestamp and three 
vectors (it's telemetry data from a magnetometer). 
 
So depending on the data rate I need to read each CSV file once a second 
and pull out either 1, 16,32 or 128 lines and then put the vectors into a 
list and then update the plot moving the data along at the data rate speed.

I wonder if there are better solutions than pandas for this? As in my 
update function I am forced to re-read the CSV file and pull the whole file 
out each time and tail the necessary lines into a copy then using the 
tolist() method

But as the file grows this is probably fighting a losing battle to be 
efficient and could even slow down the drawing of the plots?

Any advice appreciated! Thanks, Alex




-- 
You received this message because you are subscribed to the Google Groups 
"pyqtgraph" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/pyqtgraph/2511e0ea-1dcb-4bec-8dff-3c555a036fcb%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to