xy graphic

[fadetoblack]

Hello I am doing a project where I need to collect rpm data and engine load at 1Hz of frequency. My problem is: -1st - Is there a way to plot a Torque vs rpm kerb in labview ( I know the polinomium for that ) -2nd - With the data collected (rpm + engine load) I want to plot that point in the chart for every iteration. How can I do that?? I've been searching in labview help and I it seems that the graphics and charts avaiable are only in time domain. I mean, it seems only to be possible to plot something like the amplitude of a signal in y-axis and its evolution in time. Is this true?? All I want is an "excel-type" chart where I plot Torque in y-axis and rpm in x-axis, which is a known polinomium and then I only actualize the actual torque I'm using at a certain rpm Hope it is clear Thanks in advance

[CoastalMaineBird]

it seems that the graphics and charts avaiable are only in time domain.

Not true.  a different class of graphs, called "X-Y" graphs is what you need.

You feed it two arrays (Speed[ ] and Torque[ ]), or you feed it an array of clusters { Speed | Torque}.

Either way it makes an X-Y graph for you.

You probably want to turn off interpolation (lines between the points), as it makes no sense in this case. 

Look in the examples. 

Message Edited by CoastalMaineBird on 03-18-2009 11:22 AM

[Ben]

Nice new look there for you Steve,

[Set TongueInCheek =True] 

 not quite a crabby as the old one, but I don't now if its wise to be sporting a big C.

"We don't take kindly to C around these parts."

[Set TongueInCheek =False] 

Just having fun,

Ben

[CoastalMaineBird]

You really DO follow me around, don't you, Ben?  ;->

Yeah, my newly hired marketing director insisted that I take advantage of all these posts and get the name and logo out there.

At least the logo doesn't contain "+ +". 

[Ben]

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CoastalMaineBird wrote:

You really DO follow me around, don't you, Ben?  ;->

Yeah, my newly hired marketing director insisted that I take advantage of all these posts and get the name and logo out there.

At least the logo doesn't contain "+ +". 

---

I follow everyone when they are this forum. I just make a point of reading your posts because you make me laugh.

If you upload your icon to this thread it will still be visable in the event your machine goes down for maint. etc.

Take care,

Ben

[fadetoblack]

First I would like to thank for the quick reply

I found that xy graphic could really help me.

Now I can manage to plot a point (x,y) =(rpm, Torque) without problems, however, I need to plot a polinomial function where Torque is a function of the rpm. I´ve got an expression from the likes of

Torque(rpm)=a*rpm^2 + b*rpm + c. That is something I use for my own control and I need to plot it on the same xy graph where I plot the point (x,y) =(rpm, Torque).

I ask if you could help me on to plot the polinomial fuction, because the for loop isn't working (at least I couldn't manage myself...) and there is also the problem of plot it the xy chart

Thanks again

[Ben]

---

fadetoblack wrote:

First I would like to thank for the quick reply

I found that xy graphic could really help me.

Now I can manage to plot a point (x,y) =(rpm, Torque) without problems, however, I need to plot a polinomial function where Torque is a function of the rpm. I´ve got an expression from the likes of

Torque(rpm)=a*rpm^2 + b*rpm + c. That is something I use for my own control and I need to plot it on the same xy graph where I plot the point (x,y) =(rpm, Torque).

I ask if you could help me on to plot the polinomial fuction, because the for loop isn't working (at least I couldn't manage myself...) and there is also the problem of plot it the xy chart

Thanks again

---

Please post the code you have developed to this point. We can take a look and advise based on where you need the help.

Ben

[CoastalMaineBird]

Be aware that multiply, add, and a lot of other functions will work directly on arrays.

IOW, an array of 100 numbers X 5.0 + 3.14159 = an array of 100 numbers.

You don't need a FOR loop for that.