LabVIEW
Plotting a sine wave using arrays
Solved!
Hello! I wanted to see a graph plotted point by point so I built 2 arrays x and y to track the process, However, my attempt was unsuccessful. Here is what I did vs what my professor did but I don't understand why what I did was wrong. Can anyone please explain it a bit thoroughly so I have a good understanding of how to work with arrays. Thank you so much in advance!!
How I did it:
what my professor did:
(some more context:) Plotting on an XY-Graph point by point
In order to see the graph being plotted point by point, we have to send the x and y arrays to
the XY-graph at every increment.
For this reason we shall start with two empty arrays initializing the x and y values. At every iteration
we add the new values using insert to array to these arrays and plot them on the XY-graph.
@Lauren.jpg wrote:
Hello! I wanted to see a graph plotted point by point so I built 2 arrays x and y to track the process, However, my attempt was unsuccessful. Here is what I did vs what my professor did but I don't understand why what I did was wrong. Can anyone please explain it a bit thoroughly so I have a good understanding of how to work with arrays. Thank you so much in advance!!
How I did it:
what my professor did:
(some more context:) Plotting on an XY-Graph point by point
In order to see the graph being plotted point by point, we have to send the x and y arrays to
the XY-graph at every increment.
For this reason we shall start with two empty arrays initializing the x and y values. At every iteration
we add the new values using insert to array to these arrays and plot them on the XY-graph.
In your effort, you are creating a new array of one element with each iteration, for both the x and y axes and sending them to the graph. I suspect you are seeing a single dot traversing a sine pattern. What you need to do is find a way to add on the the end of the existing arrays, which is what your professor had done.
It is awkward to do it with an XY Graph because of this. Your way would work for a chart, though.
Hi Lauren,
@Lauren.jpg wrote:
1. why did we use an array constant instead of an array indicator?And why is it placed outside the loop?
2. I'm also facing issues with understanding the wiring of the index in insert array.
- You use the array constant to initialize the shift registers…
- I also have issues with those InsertIntoArray functions: most often they are used wrong! You should use BuildArray instead in your VI to append new samples to your arrays… (When you know the final array size before loop starts you should initialize the array to correct size and use ReplaceArraySubset. Or use autoindexing at loop border.)
