topic Re: How to plot data using PlotXvsY method from the AxCWGraph object? in Measurement Studio for .NET Languages

How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Wed, 13 Jul 2005 15:34:56 GMT

Hi,

I have searched through the tutoriols, knowledge base section, and forums for anything dealing with plotting points using the AxCWGraph object available for measurement studios 7.0 for VC++ .NET.

So far, I have found nothing on the topic except example code which I can not comprehend (because they use MFC classes, which my current project can not use). The main function I want to use is the PlotXvsY method made available for the class.

Apparently the method can take two parameters, x and y values to plot. But it wants of type System::Objects __gc for its parameters.

I looked at the examples which came with the software, and they all use CNiVectors to pass it in, which I understand belong to MFC classes. I was told I can not currently use the CNi class because my project isnt using MFC. Regardless, I was wondering if you can suggest me a way (hopefully easier to understand) on how to use PlotXvsY. I currently have an 1D array which holds floats and I just want to plot them onto the graph (AxCWGraph object). I hope this is clear enough on what I am trying to ask. I GREATLY appreciate the efforts and any help would be helpful. Thank you.

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

Elton Wells — Wed, 13 Jul 2005 16:55:51 GMT

If you are going to create an application using C++, .NET Windows Forms, and Measurement Studio, you have two choices to plot a 1D array of floats:

Use an interop wrapper around the CWGraph control and plot an array of .NET data values via the PlotY method. You asked about PlotXvsY, but this method is for when you're specifying both the array of x values and the array of y values. Since you have 1 array, you should use PlotY instead of PlotXvsY.
Convert the array of float values to an array of double values, then use the native Measurement Studio .NET Windows Forms WaveformGraph control to plot the array via the PlotY method.

Here is an example of using AxCWGraph.PlotXY:

float values __gc[] = { 1.0, 2.0, 1.0, 2.0, 1.0 } ;
axCWGraph1->PlotY(values);

Here is an equivalent example using WaveformGraph.PlotY:

float values __gc[] = { 1.0, 2.0, 1.0, 2.0, 1.0 } ;
double convertedValues __gc[] = (double __gc[])DataConverter::Convert(values, __typeof(double __gc[]));
waveformGraph1->PlotY(convertedValues);

Hope this helps.

- Elton

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Wed, 13 Jul 2005 17:50:33 GMT

Hi,

Thank you very much Elton. I forgot to mention my 1D array has x,y values respectively. I would jsut re organize it so I can have 2 arrays for x and y respecitively of type double and pass that into PlotXvsY.

I am assuming PlotXvsY(double x __gc[], double y __gc[]) works also?

Thanks!!

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

Elton Wells — Wed, 13 Jul 2005 17:59:00 GMT

Yes, that will work. If you want to use the native Measurement Studio .NET UI Windows Forms control, you can use ScatterGraph.PlotXY. Just out of curiosity, is there a reason that you are using an interop wrapper for the CWGraph control rather than using the native Measurement Studio .NET Windows Forms controls?

- Elton

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Thu, 28 Jul 2005 18:53:13 GMT

Hi Elton,

I hope you can read this again. How would I access Scattergraph controls in Visual C++.net?

I current have Measurement Studios 7.0 and only have AxCWGraph class when I create the graph UI.

I do want to use the PlotXY method, but the prototype for it is PlotXY(Object * __gc, Object* __gc)

I am assuming Scattergraph is PlotXY(double x, double y), which I want to use.

Thanks alot!

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

Elton Wells — Thu, 28 Jul 2005 18:57:42 GMT

ScatterGraph has PlotXY(double x, double y) and PlotXY(double[], double[]). Did you install the Measurement Studio .NET libraries when you installed Measurement Studio? If so, when you open the Windows Forms designer in a Managed C++ project, look at the toolbox and you should see a tab for the Measurement Studio .NET controls. Open this tab and you will see ScatterGraph, and then you can drag and drop a ScatterGraph to the form.

- Elton

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Thu, 28 Jul 2005 19:03:52 GMT

Thank you for the prompt response.

I probably did not install the measurement studio .NET libraries. But just to make sure.

Right now in my toolbox under measurement studio tab, I only see CW UI Objects, i.e. CWSlide, CWknob, CWGraph, etc..

So your saying under the measurement studio tab I should see a "scatter graph" object. Sorry I am new to measurement studios. Thanks!

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

Elton Wells — Thu, 28 Jul 2005 19:07:05 GMT

There are two toolbox tabs: one for Measurement Studio C++ controls and another for Measurement Studio .NET controls. The Measurement Studio C++ tab has CWGraph, CWSlide, etc. The Measurement Studio .NET tab has ScatterGraph, WaveformGraph, etc. If you do not see the Measurement Studio .NET tab, then you probably do not have the Measurement Studio .NET libraries installed. You can double-check your Measurement Studio installation directory to be sure. If the Measurement Studio .NET libraries are installed and the toolbox tab is not appearing, you can create the toolbox tab yourself and add the controls from the NationalInstruments.UI.WindowsForms.dll assembly in the Measurement Studio installation directory.

- Elton

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Tue, 09 Aug 2005 22:01:16 GMT

Hi Elton,

I added the NationalInstruments.UI.WindowsForms.dll assembly file after installing the .NET libraries. Unless I installed it wrong, I only see the waveform graph object, and not scatter graph. I currently have the Developer Suite 2004, which should include the libraries that contains the Scatter graph object I am assuming.

Again, the reason why I want to use Scatter Graph is to use the method PlotXY, and waveform graph does not have any plot methods that are useful, i.e. PlotX, PlotY, PlotXappend, PlotYappend

When I added the toolbar manually and add the items for it, I do see the NI UI.WindowsForms.dll assembly file. I chose it and clicked OK, and only the waveform graph object showed up. Any help would be greatly appreciated. Thanks!

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Tue, 09 Aug 2005 22:06:44 GMT

Nevermind, I found out what was wrong. Did not look close enough to find the scatter graph object. Sorry to bother you! thanks!

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Tue, 09 Aug 2005 22:26:46 GMT

Hi Elton,

I apologize for asking so many questions, but I really need to figure this one out. It appears that I need to liscence the ScatterGraph object or any ActiveX controls I have. I read up on the help file and it says I just need to re add all my reference files. I did just that , but it still asks that I need to liscence it when I run my program.

Any Ideas on how to liscence it properly?

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

chowchow2469 — Tue, 09 Aug 2005 22:53:45 GMT

Hi,

I have found the article regarding to my problem, and fixed it. Again, I apologize for multiple posting, and answering it myself. But this one I can not answer myself.

I am trying to use plotXY, and my graph is not plotting any data. Here is a test code I am running just to teach myself how to use it.

double

values __gc[] = new double __gc[6];

double values2 __gc[] = new double __gc[6];

int x;

for(x=0; x<6; x++)

{

values[x] = x+2;

values2[x] = x+3;

scatterGraph1->PlotXY(values[x], values2[x]);

}

What is wrong with the logic of the above code?

Re: How to plot data using PlotXvsY method from the AxCWGraph object?

Abhishek Ghuwalewala — Wed, 10 Aug 2005 13:50:28 GMT

chowchow2469,

You need to move the PlotXY call outside the loop. PlotXY clears old data before plotting new values. Since your PlotXY call is inside the loop with a single data value as the argument, the scatter graph will plot a single point for each iteration of the loop. When you move the PlotXY call outside the loop and pass the entire values and values2 array, you will see all your data displayed on the graph.

If you would like to add points to an existing set of data displayed on the graph, then you can call PlotXYAppend. PlotXYAppend does not clear the old data before plotting. It only adds to the existing data points displayed on the graph.