This is a simple OCX control, which allows you to plot two-dimensional data. Despite the large set of controls that comes with VC++, there is no out-of-the-box control that provides a simple and straightforward 2D data visualization. The ActiveX control tutorial by Kapil Chaturvedi inspired me to write my own control, mostly because I wanted to customize the source code when needed. Over time, the functionality of the ActiveX control became more elaborate, and finally I made decision to publish what I have in hand.
What Can It Do?
The control is able to plot a large number of points and updating one or more plots on the graph with new data, replacing the old plot with the new plot. Multiple plots with individual properties such as name, line and point style, width, could be customized at runtime. At runtime, the control is capable of displaying its own property pages (double click on the control area or by invoking the ShowProperties method) and showing short help as a result of the user pressing F1
while the control has the focus. By setting the TrackMode property you should be able to switch between a different modes such as tracking cursor coordinates while moving (left mouse button pressed), zooming, XY-, X-, and Y-panning. Finally the control snapshot could be copied to the clipboard, printed, or saved as a bitmap file.
What doesn't it do?
You cannot plot 3D data, but you can use the NTGraph3D ATL/STL/OpenGL activeX control
to do that :-)!
- The Log Axes Mode works now, showing the log10 grid, and appropriated labels, it also converts the graph element's data
- The control's snapshot could be now saved as a bitmap file, many thanks to Robert Harber for providing the code!
- Added abilities to dynamically creating annotation labels, that can be on different colors, orientations, and also could be hidden or visible.
- Added "Annotations" property page that provides fully access to the annotation list in the real/design mode.
- Added abilities to dynamically drawing of multiply cursors, with a different colors, crosshair styles, floating/fixed, or snapped to the currently selected element!
- Added "Cursors" property page that provides fully access to the cursor list in the real/design mode.
- Added axis formatting, that allows a customization of the bottom and left axis labels.
- Added "Format" property page that provides access to the axis format properties, and a templates for of commonly used data formats such a: Numbers, Exponential, Symbolic, Date, and Time!
- Added Time format for the graph axes. To use it, you should set the
XTime/YTime property to
You also have to convert the date/time data to
double format. The Date/Time format is implemented as a as a floating-point value, measuring days from midnight, 30 December 1899. So, midnight, 31 December 1899 is represented by 1.0. Similarly, 6 AM, 1 January 1900 is represented by 2.25, and midnight, 29 December 1899 is 1.0. However, 6 AM, 29 December 1899 is 1.25.
For more info refer to MSDN for the class:
How to test the control
You can use the ActiveX Control Test Container, and load the Test.dsm macro from the menu Tools\Macros... You can write your own routines to test the control behavior (look at Test.dsm macro)
How to use the control
To use this OCX control, embed it in an application that supports the use of OCX controls. Microsoft Visual Basic applications, Office applications and applications created with the Microsoft Developer Studio’s AppWizard can support the use of OCX controls. There are two files required to use this control. They are:
- NTGraph.hlp -The help file for this control.
- NTGraph.ocx -The NTGraph controls code and data.
Before the ActiveX control can be used in your application, it must be registered as a COM Component in the system registry. This is a self registering control. This means that to register the control in the system registry you only need to have an application load the control and call the control’s exported function DllRegisterServer. You can use the REGSVR32 utility or have your setup program do this.
How to use the REGSVR32 utility?
Copy NTGraph.ocx to your directory and type:
regsvr32 /u NTGraph.ocx
Customizing The Control
You can change the properties of this control during design time, or in run time to affect how the control will plot the data.
Use the new control property pages:
Graph Property Page
Elements Property Page
Annotations Property Page
Cursors Property Page
Format Property Page
You can include the control in your project by following the standard steps for ActiveX controls:
- Create MFC Dialog project or MDI/SDI project with View class derived from
- Choose menu Project|Add To Project|Components and Controls...
- Open the Registered ActiveX Control gallery
- Choose the
NTGraph Control and click Insert
- Visual C++ will generate the class
- Then you can define variable of the type as
The control's customization options are straightforward:
m_Graph.SetXLabel ("X Axis");
You don't need to call the control
Invalidate() function every time you change a Graph property. The changes are automatically reflected on the control appearance.
To load the data into the control...
for (int i = 0; i < NumberOfElements; i++)
for (int x = 0; x < NumberOfPoints; x++)
y = (double)rand() / RAND_MAX * 10.0;
y = y / 3 + 10.0 / 2 * i + 1;
m_Graph.PlotXY(x, y, i);
The same story for Visual Basic Users:
.PlotAreaColor = vbBlack
.FrameStyle = Frame
.Caption = ""
.XLabel = ""
.YLabel = ""
.ElementLineColor = RGB(255, 255, 0)
.ElementLineColor = vbGreen
For X = 0 To 100
Y = Sin(X / 3.15) * Rnd - 1
.PlotY Y, 0
Y = Cos(X / 3.15) * Rnd + 1
.PlotXY X, Y, 1
.SetRange 0, 100, -3, 3
short CursorMode (0 - Fixed; 1 - Floating; 2 - Snapped to currentlly selected element)
short CursorStyle (0 - Crosshair; 1 - X hairline only; 2 - Y hairline only;)
void SetRange(double xmin, double xmax, double ymin, double ymax)
void DeleteElement(short ElementID)
double GetElementXValue(short index, short ElementID)
void SetElementXValue(short index, short ElementID, double newValue)
double GetElementYValue(short index, short ElementID)
void SetElementYValue(short index, short ElementID, double newValue)
void PlotXY(double X, double Y, short ElementID)
void PlotY(double Y, short ElementID)
void DeleteAnnotation(short AnnotationID)
void DeleteCursor(short CursorID)
Tracking Mode constants
- None = 0
- Track = 1 Track cursor position (hold mouse button pressed)
- Cursor = 2 Cursor position by single click
- Zoom = 3 Unzoom (right mouse button click)
- PanXY = 4
- PanX = 5
- PanY = 6
Frame Style Constants
- Flat = 0
- Scope = 1 (raised frame and sunken plot area borders)
- 3DFrame = 2 (a bitmap frame picture)
Line style constants
- Solid = 0
- Dash = 1
- Dot = 2
- DashDot = 3
- DashDotDot = 4
- Null = 5
- XYStep = 6
- YXStep = 7
- Bars = 8
- Stick = 9
Symbol style constants
- Nosym = 0
- Dots = 1
- Rectangles = 2
- Diamonds = 3
- Asterisk = 4
- DownTriangles = 5
- UpTriangles = 6
- LeftTriangles = 7
- RightTriangles = 8
Yep, that's it!
Send mail to email@example.com with questions or comments about this article.
22 Nov 2002 - v1.0 Initial release
01 Dec 2002 - v1.1
- Added new method copy2clipboard.
- Added the ability to draw elements with a different number of points. (by A.Hoffman)
- New method added by A.Hoffman to Show/Hide the Graph Element
- Bug fix. Thanks to A.Hofmann for help.
- Fixed some drawing problems. Thanks to Judd.
- Added custom font support.
- Zoom Mode: Not implemented yet, but reserved.
26 Jan 2003 - v2.0 (Flicker Free versiton of the control)
- Thanks to Keith Rule for the class
- ZoomMode Implemented.
- Added tooltip, showing current cursor position.
- Added new method
- Added new property
- Added new property
- Fixed some drawing problems.
- Added (Test.htm) a brief info on how to add the control to your web page.
09 Mar 2003 - v2.1
- PanMode Implemented.
SetElementLinetype, so that they accept as a first parameter the ElementID.
- Fixed some drawing problems. Should be clean now.
- GDI leak Fixed.
01 Jun 2003 - v3.0 New release!
02 Aug 2003 - v4.0 Final release!
- Thanks to Robert Harber for the useful discussions, ideas and code.
- Thanks to tagi1 for fixing the printing font problem.
- Thanks to Judd for testing the control.
Note that since there are significant changes in the last release you should remove (first unregister and than delete) all old versions of the control from your projects! The VBA users who use the control inside of Office applications should also remove the following file NTGRAPHLib.exd in the Temp directory of your computer. This file is automatically created by the Office application and saves properties of the former created control instances. You have to delete this file before you insert the new version of the control, in order to get correctly names in the property browser.