3.2 Java1492-plotting large quantities of data using java  (Page 6/27)

The class named PlotALot03 also provides all of the general capabilities described earlier for the class named PlotALot01 that are appropriate for a two-channel plotting system.

Figure 3. Sample output for PlotALot03 class.

Same data, two colors

The two sets of data plotted in Figure 3 consisted of exactly the same values. Thus, the plots on the even numbered axes look just like the plots onthe odd numbered axes except that one plot is red and the other is black. Using the same values for each set of data makes it easy to confirm that both plottingprocesses are behaving the same way.

The plotting parameters

The overall plotting parameters for Figure 3 are shown below:

Because PlotALot03 doesn't superimpose the two sets of data, twice as many pages would be required for PlotALot03 to plot a given amount of data as would be required by PlotALot02 for the same Page size.

PlotALot03 will refuse to plot data for a set of plotting parameters that result in an odd number of traces on the page.

Sample output for PlotALot04 class

The class named PlotALot04 plots three sets of data on separate horizontal axes as shown in Figure 4 . The first set of data is plotted in black. The second set of data is plotted in red. The third set of data is plotted in blue. Thisclass is particularly useful for displaying the input, output, and error signals involved in adaptive signal processing, for example.

The class named PlotALot04 also provides all of the general capabilities described earlier for the class named PlotALot01 that are appropriate for a three-channel plotting system.

Figure 4. Sample output for PlotALot04 class.

Same data, three colors

The three sets of data plotted in Figure 4 consisted of exactly the same values. Thus, the plots on the three different axes look just alike except thatthe first plot is black, the second plot is red and the third is blue. Using the same values for each set of data makes it easy to confirm that all threeplotting processes are behaving the same way.

The plotting parameters

The overall plotting parameters for Figure 4 are shown below:

PlotALot04 will terminate if the number of traces per page is not evenly divisible by 3

Sample programs

The class named PlotALot01

Now that you know where we are heading, it's time to examine these four classes in detail. I will begin with the class named PlotALot01 .

Purpose of the class

This class is designed to plot large amounts of data for a single channel. The class is particularly useful for plotting time series data. Also, bycarefully adjusting the plotting parameters, this class can be used to plot large quantities of spectral data in a waterfall display with each new spectral estimate being plotted immediately below the previous estimate.