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High Frequency Propagation Forecast --> New Version April 98

The new Version is using a new format of the map data .GIF file.

The Java applet HFMapViewer works as stand alone application and as applet viewed with MS-IExplorer 3.0 or Netscape Navigator 3.0 or newer.

Once loaded, you can cut the phone line to save money, but check first you get all 24 maps by steping trough the hours or activating the animation. Viewing this animation can be done offline or as stand alone Windows application using jview.exe. Under Windows95 I was not able to run jview.exe with this long names outside the J++ Developer Studio but under Windows NT 4.0 it works with command: jview.exe HFMapViewer. This Applet has been tested using the JIT option.

By rebuilding your own Palette class you can redefine the color legend. Do not define more than 16 colors. Just replace then the Palette.class with your new Palette.class.

Maximum usable Frequency for this month -----------------> load, run the applet now
HFMapViewer -----------------> how to use offline
HFMapViewer -----------------> change the color palette


HFMapViewer - how to use offline or in your own html document

The only changes from month to month are the html page text and the map data gif file. Save this gif file to your computer together with world.gif and all classes to get a workable offline set. To save the classes for offline use, download here or pick all this files from your internet cache:

HFMapViewer.class -----------------> the applet
HFMapViewerFrame.class --------> the frame of the application
MapView.class ------------------------> display the map image>
MVPanel.class ------------------------> the control panel
Legend.class ---------------------------> draws the legend
Palette.class ----------------------------> defines the colorset
World.gif ---------------------------------> Worldmap picture
J30MUF04.GIF -----------------------> April map data as bytestream container in a GIF file!

Some browser wont accept the strange GIF size of 23000 by 1 of the J30MUF04.GIF and returns a broken icon only. But from now, the new version of HFMapViewer is using a map data GIF file of 1000 by x. This data are used to create the 24 hour maps. It's not a picture, you see just a gray pattern, it's a bytestream container of about 30k. A nice Java byte array class needs for the same amount of data 180k and is too large for the current internet speed. Inside the Viewer the GIF-Picture is loaded using getImage() and the data bytes are regained using the PixelGrabber() method.

To facilitate the download, the actual set is now available as selfextracting file.
Download the applet for this month, all components in HFMapViewer.zip (36K)

With this set of classes enter the next lines to get the applet working in your html document or view the html source of the current page with your browser.
The MapFilename and the Type Parameter in uppercase is a must !!


         <applet code=HFMapViewer.class id=HFMapViewer width=500 height=300 ALT="HFMapViewer Java Applet">
         <param name=MapFile value="J30MUF04.GIF ">
         <param name=Month value=" Apr.98">
	 <param name=Type value="MUF">
         </applet>

HFMapViewer - redefine the color palette

A quick replacement is just to use the palette.class of the WorldGround applet. Use 0, 51, 102, 153, 204, 255 or hex. 0x00, 0x33, 0x66, 0x99, 0xcc, 0xff for undittered color and if you have a Java SDK installed then redefine the Palette class using this source:


// my Color Palette definition for 16 colors
import java.awt.*;

public class Palette 
{
    static public Color[] c =
    {
		new Color(  0,   0,   0), //0	
		new Color(204,   0, 204), //1	
		new Color(  0,   0, 204), //2	
		new Color(  0, 204, 204), //3	
		new Color(204, 204,   0), //4	
		new Color(204,   0,   0), //5	
		new Color(  0, 204,   0), //6	
		new Color(255, 255,   0), //7	
		new Color(204, 204, 204), //8	
		new Color(  0,   0, 255), //9	
		new Color(255,   0,   0), //a	
		new Color(  0, 255,   0), //b	
		new Color(255,   0, 255), //c	
		new Color(  0, 255, 255), //d	
		new Color(255, 255, 255), //e	
		new Color(102, 102, 102)  //f	
    };
}

Now you can just change the values for R G and B for each Color( R, G, B). The values goes from dark 0 to bright 255. //n is comment indicating the color index in the c array. Later in the application, the color is referenced as Palette.c[i]; The array size is set by the compiler. Use a Java compiler to compile the saved Palette.java file. This will generate the file Palette.class that will replaces the current class in the WorlGroundMap applet. To replace it, move/copy the Palette.class file to your HFMapViewer directory. Finaly run the applet opening the html file. That's all !



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