From: 1231 on 25 Feb 2006 09:40
how do i plot a graph of energy vs time? i have the power calulated. i would like to plot energy vs time graphs for a wireless sensor mote on 0dBm and 20dBm and see the comparison.
i need to integrate ? or can i do it on excel?
From: Kurt NI AE on 27 Feb 2006 06:40
LabVIEW graphs and charts are powerful in their means of presenting data. Charts ideal for scrolling through real / continious data i.e. that which is streamed across the plotting area. Waveform graphs work with array data type and plot in the order y=f(x). In this the index value for each element in the array is usually used as values for the x axis. XY graphs allow you to plot data without the fixed point spacing introducing greater flexibility and allowing one to plot wonderful curves, XY graphs accept 2 dimentional arrays for each axis etc. The context help guide is very useful for checking out what you need to wire up.
Arrays are essentially a set of data of the same data type for example a list of numbers. If you have already calculated your values for each axis you can plot these corespondingly. If you are working with LV 7.0 express or higher, you can use the Read from LVM file express VI [one with a blue background] to read from excel assuming you have the data already populated in cells of your excel spreadsheet file. Its quite simple, perhaps you could attach the excel file and I would gladly see what i can come up with.
You can programmatically calculate your vaules on the block diagram using the many mathematical functions that are available or even with the formula node.
<a href="http://en.wikipedia.org/wiki/Electric_energy" target="_blank">http://en.wikipedia.org/wiki/Electric_energy</a>
I hope this helps!
From: 1231 on 27 Feb 2006 12:10
here is an excel file i got. with all my values filled in, bar the energy.....
From: Kurt NI AE on 28 Feb 2006 07:40
I'm not sure what version of LabVIEW you are working with, but attached to this post is an attempt that my colleague and I have made to essentially obtain the data in to LabVIEW 8. All that you need to look into is introducing graphs to display the data as plots. In the example we have read the data from the excel spreadsheet you attached ... done relevent calcualtions in labview to obtain energy vaules and displayed results in an array indicator.
hope this helps!
From: 1231 on 28 Feb 2006 09:40
i got version8, thats fine, but i dont want to do labview testing on all these again, i have 25megs of excel to graph! so i was hoping to use excel for this?