Creating a chart with another variable besides time on X-axis

[parker300]

Hi, 

This seems like a simple fix, but I am struggling to find a solution. I'm trying to create a chart that plots pressure on the X-axis against flowrate on the Y-axis in order to generate a flow curve. I know this is easy to do using a graph and the express VI, but I want to see the entire history of the curve. How can this be done?

[RTSLVU · Accepted solution]

Have you tried an XY Graph? Anything can be the X-Axis (Time is just the default) and your entire X and Y graph history is held in a cluster of arrays.

[altenbach]

Unlike a graph, a chart has a built-in history buffer of defined size. Once you add more points, the oldest are irreversibly lost.

If you want to use an xy graph, you need to accumulate the data in your own history (I don't really recommend the "build xy graph express VI", too inflexible).

Are your pressure points spaced equally? In that case a plain graph would simplify things. While the x-axis is by default labeled as "time", you can name it anything you want, for example "pressure". You can also define x0 and dx to correctly map array indices to markers.

Typically we can give much more specific recommendations if we have more detail, for example you could attach a simplified VI simulating your typical data.