XY Graph Axis's autoscale but no plot shows?

Question

I just don't undestand XY Graphs.
I have folowed the examples, tried the xy graph express vi,  even gone as far as copying and pasting the example vi right into my own program.
The axis's autoscale but the plot never shows on the graph?

Answer 1

You only generate one point for each iteration of the large FOR loop and, unlike charts, XY graphs don't keep a history. You might get what you want by double-clicking the "Built xy graph" express VI and unselect "clear data on each call". I don't really use that feature.
How fast does the loop run? Maybe it's OK to build the x and y array at the loop boundary and only plot at the end of the loop (green insert of image)? FOr continuous update while the loop is running, you could also build the x and y arrays in a shift register (upper part of image).
Notice that you don't need to do the complicated detour via a 2D array. Simply keep it as 1D array and insert an "array to cluster" for the chart (see image). Don't forget to set the cluster size to 3 by right-clicking on "array to cluster".
Message Edited by altenbach on 02-12-2007 03:56 PM
Message Edited by altenbach on 02-12-2007 03:59 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
XYUpdate.png ‏33 KB