labview unbundle 2d array

Question

Using Labview 2017, I'm trying to xy-plot 2d list from a CSV file, but can't connect it right.

How does the connection should be?

Answer 1

So, if you open the Context Help window and then hover over the XY Plot Matrix Helper VI, it has a blue link for "Detailed Help". If you click on that, you can read about the node, and at the bottom of the help is a button for "Open Example". If you open the example program, it shows you how to use the node.

The example is located at this path:

examples/Controls and Indicators/Graphs and Charts/Math Plots - 2D/XY Plot Matrix.vi

So... if you open that example, it says, very clearly, "Each column in the X Columns array will be paired up with each column in the Y Columns array to generate a matrix of XY plots. In this example, since there are three X columns and two Y columns, a total of 6 XY plots will appear in the XY Plot Matrix indicator."

Your data is coming from a CSV file as a 2D array. I'm guessing you want to view only a single plot. That's a guess. I honestly have no idea. So you'll need your X data in one column and your Y data in another column. You're going to have to build that conversion manually. What's the data layout in your CSV file? I'll make a guess... let's say your CSV has 2 columns: the first column is your X values, the second column is your Y values. Something like this (click the "Run code snippet" to see the data table):

<table border=1><tr><th>x</th><th>y</th></tr><tr><td>1</td><td>10</td></tr><tr><td>2</td><td>20</td></tr><tr><td>3</td><td>30</td></tr><tr><td>4</td><td>40</td></tr><tr><td>5</td><td>50</td></tr></table>

If that's correct, then you'll need code like what I've got below. If that isn't correct, then you'll have to develop your own similar code based on your file format. The possibilities are endless, so I cannot possibly list them all.

Note that this picture is a VI Code Snippet PNG. Save the file to your disk and then drag the file from your file system directly onto a block diagram and LV will reconstruct the code that is in the image. Useful when posting to StackOverflow... just select some code and use "Edit >> Create VI Snippet From Selection" to make these PNGs.