From 04:00 PM CDT – 08:00 PM CDT (09:00 PM UTC – 01:00 AM UTC) Tuesday, April 16, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

LabVIEW Idea Exchange

cancel
Showing results for 
Search instead for 
Did you mean: 
X.

Export data to clipboard Size Warning

Status: Declined

Any idea that has received less than 3 kudos within 3 years after posting will be automatically declined.

I would suggest adding an option limiting the size of data exported to the clipboard (or intelligently computing it based on available RAM and cores).

Alternatively allow aborting this operation (via a progress bar of some kind) or at the very least warn the user.

 

I have been bitten repeatedly by the fact that exporting to the clipboard involves converting binary data (say DBL: 8 bytes x 2 per point for a XY Plot) to ASCII (and transposing the data into neighboring columns), which, when choosing 6 digit precision (the maximum allowed today), can result in:

- Explodingly large memory footprint (potentially an issue on 32 bit systems)

- Huge execution time (meaning you have basically to kill LabVIEW).

 

I am not sure it is a coding issue, as I have not been able to come up with any way of handling large data sets fast (but I haven't tried hard and even then, I would not claim to be particularly good at optimizing algorithms). But if it isn't then it is a sure receipe for frustration.

4 Comments
X.
Trusted Enthusiast
Trusted Enthusiast

I did some fairly simple testing and I came to the conclusion that this problem must be due to some inefficient coding on NI's part (might be robust and make a lot of tests and so forth like the similarly very inefficient General Histogram VI, but from a user's point of view, it is practically useless for large data sets > 100K data points).

I took a simple Graph (not XY Graph, just single DBL array Graph) and generated a ~300K points plot.

Wrote my own simple code to generate the X axis for the graph, convert X and Y for each point into a string, output this as an array and pass that to the Write to Text File function (not exactly what the "Export Data to Clipboard" does, but one of the intermediate step is identical: generating a transposed string representing the whole plot). From calling this function to closing the file, the task took 22.4 s on my PC. 10 min after I selected "Export Data to Clipboard", LV is still locked and working on that task.

 

I'd call for a CAR...

X.
Trusted Enthusiast
Trusted Enthusiast

Make it about 1 hr...

X.
Trusted Enthusiast
Trusted Enthusiast

Just had to kill LabVIEW again for the exact reason I was describing. I am surprised by the fact that nobody seems to agree this is a major issue...

Darren
Proven Zealot
Status changed to: Declined

Any idea that has received less than 3 kudos within 3 years after posting will be automatically declined.