How can I delete a curve from a graph? thanks

[User_1979]

Hi Everyone,

I am using Labview 2011 and I would like to know how to delete curves from plot (adding is fine).

Would anyone know?

Thanks,

User

[User_1979]

Hi Everyone,

I am using Labview 2011 and I would like to know how to delete curves from plot (adding is fine).

Would anyone know?

Thanks,

User

[smercurio_fc]

You have to delete the curve from the dataset. The graphs plot whatever you send them.

Or, do you just want to make the plot not visible? You can do this by displaying the legend and then right-clicking on the legend to show the plot visibility controls. You can also set the visibility programmatically. This has been shown many times in the forum. Search.

[User_1979]

Hi,

Thanks for your time. I do want to delete the curves of my graph (I already know how to make them invisible). For example in the attached VI I only want to keep the first 2 curves, but I can't find  any "delete" function in the property menu of the Icon. It gives a list of 15 curves...

User

[User_1979]

When I only wire 2 entries to the graph the list still consist of 15 curves and not 2.

[smercurio_fc]

What is that VI supposed to show? All I see is a front panel indicator. There is no code. Where is the data coming from? Are you dealing with dynamic data? If so, then it's clumsier than dealing with just an array of waveforms. You have to either use the Select Signals Express VI to select which signals to send to the graph, or you can use the Split Signals and then the Merge Signals to get your new dataset.

[User_1979]

I was just trying to show my problem : list of 15 curves when clicking right + propriety+curves on the graph icon. I have attached a VI showing how my chart is fed.

If anyone knows,

Thanks

User

[altenbach]

You could just place a "Select Signals Express VI" into your dynamic data wire leading to the graph terminal.

(EDIT: Ah, saverio already suggested it, sorry for the noise ;))

[User_1979]

Hi,

I have been trying to select the expected number of signal (select signals express VI and Index array) but it doesn't change anything to the number of signal in the list (see .bmp). Is that what you were telling me to do or am I misunderstanding?

Thanks,

user

[smercurio_fc · Accepted solution]

What you are seeing is a REALLY ANNOYING behavior of the chart. I've seen this before, but I'm not sure if this has been reported as a bug, but if not, I'd call it one. What happens is that once you resize the legend, the chart "remembers" the plot names. It doesn't matter if you actually only feed it two plots. Here's how to reproduce it:

1. With the code you provided, place a new chart on the VI. Do not change any properties of the chart.
2. Connect the chart to the output of the Merge Signals function.
3. Run the VI.
4. Open the properties on the plot legend, and you should see 10 plots.
5. Close the chart properties. Do NOT change anything.
6. Reconnect the chart to the output of the Select Signals VI.
7. Run the VI.
8. Open the properties on the plot legend, and you should see 2 plots. Expected behavior.
9. Close the chart properties. Do NOT change anything.
10. On the front panel, resize the plot's legend so that it shows up to, for example, Plot 5.
11. Open the properties on the plot legend. You should see 6 plots.
12. Close the chart properties. Do NOT change anything.
13. Run the VI.
14. Open the properties on the plot legend. You will still see 6 plots.
15. Close the chart properties. Do NOT change anything.
16. Resize the plot legend back to show only one plot.
17. Open the properties on the plot legend. You will still see 6 plots.
18. Close the chart properties. Do NOT change anything.
19. Run the VI.
20. Open the properties on the plot legend. You will still see 6 plots.

I think this is incorrect behavior. You can change the number of plots shown in the legend programmatically if you wish to do that. That simply changes the size of the legend.

[User_1979]

I will save time knowing this is a kind of bug then and not wrong manipulation.

Thanks a lot for your help.

User