Five data visualization tools in Linux

In this article, Gnuplot will investigate many popular Linux data visualization tools and further explore some of them. For example, does a tool provide a language for numerical calculation? Is this tool interactive or does it provide a batch processing mode for independent operations? Can I use this tool to process images or digital signals? Does this tool provide language binding to support integration with user applications (such as Python, Tcl, and Java programming languages )? The Gnuplot of some tools will also be displayed.

In this article, we will conduct a survey on many popular Linux data visualization tools and further discuss some of them. For example, does a tool provide a language for numerical calculation? Is this tool interactive or does it provide a batch processing mode for independent operations? Can I use this tool to process images or digital signals? Does this tool provide language binding to support integration with user applications (such as Python, Tcl, and Java programming languages )? The graphic processing capabilities of some tools will also be displayed. Finally, the strengths of each tool will be analyzed to help us determine which tool is best suited for computing tasks or data visualization.

The Open Source tools explored in this article include (the licenses used by each tool are also provided ):

Gnuplot

Gnuplot is a good visualization tool that has existed since 1986. Without a gnuplot graph, it is difficult to read the paper. Although gnuplot is a command line-driven tool, it is also evolving and now supports many non-interactive applications. For example, it can be used as a GNU Octave Drawing Engine.

Gnuplot has good portability and can be used in UNIX®, Microsoft®Windows®, Mac OS®X and many other platforms. It supports a wide range of output formats from postscript to recent PNG.

Gnuplot can be operated in batch mode. It provides a command script to generate a graph and runs it in non-interactive mode, this allows us to try its features to understand the effects of their plotting.

There is a standard Math Library corresponding to the UNIX Math Library in gnuplot that can be used. Function parameters support integer, real, and complex types. You can set the math library to radians or degrees (the default is radians ).

To plot, gnuplot can use the plot command to generate a 2-D graph, or use the splot command to generate a 3-D graph (as a 2-D projection ). Using the plot command, gnuplot can be operated in the Cartesian two-dimensional coordinate system. The splot command uses the Cartesian coordinate system by default, but it also supports spherical or cylindrical coordinate systems. You can also draw contour lines in the graph (as shown in figure 1 below ). There is a new style of drawing pm3d that supports drawing 3-D and 4D data mapped using the color palette as map or surface map.

The following is a simple gnuplot example, which provides a 3-D image with contour lines and hidden line elimination. Listing 1 shows the gnuplot command used, and Figure 1 shows the generated graphic result.

List 1. Simple gnuplot function Diagram

Listing 1 fully shows how simple the gnuplot command set is. The sampling speed and drawing density are determined by samples and isosamples, and the title is provided by the title parameter for the image. At the same time, basic contour lines and hidden line Elimination features are also enabled. The final plot is created using the splot command using functions in the math library. Result 1 is displayed.

Figure 1. A simple plot of gnuplot