Move line on graph with mouse

[John Rich]

I have what I believe to be a unique application where I need to draw a line on a graph which can be moved by simply clicking in predefined boxes attached to the line. Boxes above and below the line in the upper right and lower left will be used to rotate the line relative to the axes while boxes above and below the line at the center of the line will be used to adjust the position of the line at a given angle. The attached file shows an example of how the line should look from a similar project programmed in C.

As you might imagine, what I am trying to do is set a threshold line. Therefore, I need to be able to read the line position for use in thresholding.

I know that this can be accomplished in a roundabout way by placin
g a transparent picture control over the graph, but I was wondering if someone knew of a more robust way of doing this.

I am using LabVIEW 6.1 FDS.

[Liz F]

Hello John,

Please take a look at the program I attached. It makes use of VI references and property nodes to programmatically modify the appearance of the decoration. You could easily modify this for your needs.

I hope this helps! Please let me know if I can be of further assistance.

Liz Fausak
National Instruments

[John Rich]

Thanks for your reply. Unfortunately, this doesn't do what I need. I need for the coordinates of the line to be related to the graph coordinates and not the screen coordinates. I realize that I could do this in a roundabout way by converting from screen coordinates to graph coordinates by using the location of the graph on the screen and the extents of the graph, but I was hoping for a simpler method.

Thanks,

John