The problem is: i am testing an engine and i must see the evolution of differents things (evolution of temperature, evolution of O2, evolution of CO2...). I have to see all of these evolutions on a graph. But i would like to be able visualizing this graph one day after, two days after...when i want. So, how can i do to register this graph on my computer? (sorry for my english!)
How you make graph: you have some vector or array of data and plot it in graph. O.K? Save this data to file and next time when you read the data you plot it again. For saving/reading data to/from file you have Write/Read To/From Spreadsheet File.vi. See help of this vi's. Using of them is very simple.
One additional that your other responses didn't touch on is that if you save your data with a LV timestamp for each sample (you know: the number of seconds since midnight GMT 1904) you can do some really neat things when you go to plot the data.
For example, assuming a file structure where each row contains one set of readings and the first value is your timestamp, read the whole file using one of the techniques the other posters have given. The result will be a 2D array of floating point values. Now extract the column of data containing the timestamps and use it for the X axis of an XY plot. Now, on the front panel, right-click on the graph's horizontal axis and select "Formatting...". In the resulting dialog box select "Time & Date" on the Format popup menu and click OK.
Now when you plot whatever other columns of data you want, they will be shown relative to the time and date they were collected. Very Cool...
PS: I can send you an example if you would like to see it.
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