Building an Array

[CastleWorks]

I have what is a probably a very basic question and need some direction on building an array.

I want to graph the following equation Y=a0+a1x+a2x^2. for values of x that are equally spaced at 1mSec. I can calculate Y, no problem but struggling with how to build an array of X & Y values that I can plot.

I have tried using a for loop and building an array within the loop and sending it to a waveform graph but end up with a crazy amount of plots. Not sure what I am doing wrong.

Thanks

Newbie

[aputman]

Attach a snippet of what you have tried, an example dataset, and what you expect to see from the dataset.  And by snippet, I mean, click Edit -> Create VI Snippet from Selection. 

[daveTW]

Look at the help window of the graph indicator, or open the Help / Find Examples - Window, then type "graphs" into the search field. This guides you to the different datatypes a graph indicator accepts.

Btw. it is a difference between the graph and chart indicator

[CastleWorks]

I tried to first just create a simple random number for Y and increment x by 0.001 on each itteration of the for loop.

Here is the code

[RavensFan]

Okay.  So now you have a 2-D array where column 0 is your "Y" random value.  Column 1 is your "X" value ( 0, .001, .002, .....)  (I would have swapped the inputs to the build array so that X is column 0 and Y is column 1.)

So now you should be able to figure out how to apply your equation to the X value to get your Y value.

[CastleWorks]

I swapped the array inputs as you suggested.

The part I am not getting, is the plot....here is the graph that is being generated. Do I need to generate the graph inside the for loop?

[aputman]

Did you do what Dave suggested?  Look at the help file for the waveform graph and you will see the datatypes that are accepted and the resulting graph.  A 2D array results in multiple plots rather than a single plot. 

[aputman]

Maybe an XY Graph is what you need?

[RavensFan]

Since your X values are evenly spaced, that suggests a waveform chart/graph would work.  If you want to do it within the loop, just use a waveform chart as that maintains the history of past points.  So just wire the Y value to a waveform chart.

[CastleWorks]

Hmmm....I am using a waveform graph in several other places inthe program and wanted to stick with that.

Rethinking here.....else where I am only plotting a 1D array, perhaps I do not need to generate the x values and the waveform will space them equally, which would allow me to compare them to other waveforms