extract data from graph

[jylok1]

i have datas plotted into a wavegraph graph. i would like to extract values from the graph. for example, exctract values when a paricular condition is satisfied and after extracting it should be able to able to plot into a new graph and show the results. i would to extract the data every time the condiiton is true. all the data save into the graphs should be easily obtained by choosing from a option like combo box in the front panel. thank you.

[MikeS81]

Hi jylok1,

plaese explain a bit more in detail? Where do you get the data? To use the functionlity of a combobox, i think to have to play your data again, except you measure it. If you have your data already in your graph, then you can use cursors to mark a range which you want to cut.

Hope it helps.

Mike 

[jylok1]

thanx.

i acquire the data from the hardware. however, not all values that i have plotted on the graph is useful data. so i want to extract the useful data ( according to a criteria) into few other waveform graphs.

the number of new plots is unknown. there could be 10 sets of datas that i want from the origibal plot. could be more than 10. therefore i want an option in the front panel to select the particular plot that i want.

thank you,

[MikeS81]

Hi jylok1,

you can use something like this. Build your graph data only if you want it.

Hope it helps.

Mike 

[jylok1]

hi there!

thanx alot for the VI. but i dun have the DAQmx options.

is there any other options???

thanx alot!

[MikeS81]

Hi jylok1,

how and in which format do you acquire the data? Can you show what you have done so far?

Mike

[jylok1]

thanx alot mike.

i'm almost got it. just that i have new problem.how do only execute a case structure for once.

for example, if my criteria is true for value above 3.0 (raw data), then the true case structure will be executed, then the values will be stored into an array. however, when the condition is false, i only want to execute the false case once whereby a want to add a constant into into the array.

thanx alot!

[MikeS81]

Hi jylok1,

you can use inverted logik. Use a button with mechanical action "Latch When released". The status of the button will change back after it was read by LabVIEW. So if you press the button, you will ones run the specified case and otherwise the other.

Hope it helps.

Mike 

[jylok1]

hi mike,

thanx for the suggestion.

attach here is part of my VI that i'm using to add to a constant of zero for the false case. however, when the conditon is false, i only want it to be executed once although the condition is still false.

thank you. 

[MikeS81]

Hi jylok1,

please see the attached example. It shows what i mean.

Hope it helps. 

Mike