How to plot waterfall chart

[madhaw4]

Hi,

I wanted to generate waterfall chart using jfree chart. Can any one help me?

Thanks

Madhaw

[david.gilbert]

I'm not sure what a waterfall chart is...can you post an example?

[Sir Henry]

It seems that there are differing definitions of what a waterfall display is.

In my context of frequency spectrum analysis, I would like to display a 3-dimensional dataset like it is done in the Bubble Chart Demo. I have time on the x-axis, frequency on the y-axis, and amplitude on the z-axis. Spectrum analysers normally visualise the z-axis with varying color intensities. Such a chart is in my context referred to as a waterfall display.

Has anybody got any experience with such types of charts, and would it be feasible to use JFreeChart for it?

Thanks for any response.

[david.gilbert]

Since the original post, we've implemented the following "waterfall" chart (not what you're looking for):



The ContourPlot in JFreeChart sounds a little more like what you are describing - someone else wrote this code and I haven't done a lot of work with it, but perhaps you can try it out.

[Sir Henry]

Yes, we better stick to your definition of a waterfall chart in this context and perhaps use the term "intensity chart" for what I am looking for.

I will definitely try out your suggestion.

Any further hints are welcome.

[Sir Henry]

David, you were right, this contour chart is exactly what I was looking for:



Like others did, I also noticed a rather poor performance. Is there still any development ongoing or would it be worth starting to look for improvements?

Cheers,
Sir Henry

[Guest]

Addition:

In particular I would like to have the ability to add data series to the right and automatically remove series from the left.
Currently I have to recreate the full ContourDataset with each update.

[Kagetto]

Does anyone know how Sir Henry was able to accomplish the waterfall contour chart image shown here?

I am having a hard time figuring it out. If I feed the ContourDataset a bunch of XYZ points, it messes up the graph horribly. For instance if I do something like:

Code: Select all

Vector x = new Vector();
Vector y = new Vector();
Vector z = new Vector();

for(int i = 0; i < 20; i++){
  y.add(new Double(i));
  for(int j = 0; j < 20; j++){
    x.add(new Double(j));
    z.add(new Double(j));
  }
}

CountourDataset data = new ContourDataset("Bleh", x.toArray(), y.toArray(), z.toArray());

The code will not draw horizontal lines for the different y values specified and has only one color for z that shows at the far right end of the graph. I need it to draw all of the horizontal lines (which is why I have many x,z points for the same y) and interpolate the colors (the z values) between the x values I give it....

Any help would be awesome.

~Kagetto

[Kagetto]

I switched the x and y arrays and now it works. In other words, I moved time to the x axis as shown in the contour chart image. =)

[mhilpert]

Is it possible to change the color of each category seperately?

[Kagetto]

I may not full understand your question but you can change the colors of the Z axis using a ColorPalette:

Code: Select all

        zColorBar = new ColorBar(zAxisLabel);
        zColorBar.setColorPalette(new color palette);
...
        ContourPlot plot = new ContourPlot(dataset, xAxis, yAxis, zColorBar);

~Kagetto

[mhilpert]

Hello? My question was tied to this thread => Waterfall chart. I ask, if it's possible to change the colors of each bar of the waterfall chart?

[m.ibbrahim]

hey,
even i m searching for that.. pls send me the link of the example demonstating how to change the colors of each bar of the waterfall chart..