I tried several Linux software for plotting the graph. These are some of my summaries of review.
The graph is not in Cartesian form. But very convenient and easy to define the equations.
Very difficult to prepare the graph and difficult to manipulate the graph. Need a lot of commands.
Similar to Gnuplot, can use the table form as the data. Can work with ods and excel files. Can use latex to add the label. Can define the function of graph easily. Much more better than Gnuplot. But the graph is not the Cartesian form.
Too user unfriendly.
Best for education. It uses Cartesian coordinate system. But does not preserve the aspect ratio of the Cartesian grid.
Also good for education. But cannot get the label (scale) on the axes.
As a conclusion, I normally use Genius for general mathematical calculation purpose, such as calculating the fractions, matrices, and vectors. I use Gnuplot only for generating the graph from bash scripts by reading the text files if necessary. And lastly, KmPlot is the best I like especially for education. Because it shows the axes clearly. KDEdu has a lot of nice software.