Matlab line graphs

However, here we leave all numerical procedures and MATLAB coding as exercises to the students and readers. For each problem, all the necessary modeling and data is included, as well as samples of numerical results in the form of tables and graphs. Our readers should now be able to use the models and the given parameters to develop their own MATLAB codes along the lines of what has been practiced before. Then the students should be try to solve the exercises given at the end of each section and finally the general exercises at the end of the chapter. 

MATLAB is a very simple language for computations. Its lines of numerical code are often few and short. By comparison, the visual output and the proper texting of graphs created in MATLAB may take much more effort than the numerics. 

The MATLAB program threeCSTR.m contains a few lines of numerical calculations at its top that generate the numerical solution for the IVP in equation (6.144), followed by more than two pages of plotting and graph annotation code, and it finishes with the right-hand side DE equation evaluator for the nine DEs collected in the equations (6.135) to (6.143). 

MATLAB allows users to change the color as well as the line style of graphs using a third argument in the plot command. For example, using the same arguments used to generate the plot shown in Fig. 

NOTE Notice here how MATLAB shows each command line within the M-file itself. Use echo off to suppress printing out each step, except for statements that do not end up with the suppressing symbol ( ), or for non-suppressible data and graph display (e.g., disp, plot, fplot, fprintf, etc.). 

Note that the Matlab ODE solver is given three arguments the function evaluating the right-hand side of the differential eqnation, the time interval to integrate over, and the initial conditions. The first line of code (opts) sets the relative error tolerance to le-4 (default is le-3). This line is followed by a command which calls the ode45 solver, and specifies that the differential equation is specified in the m-file. Fmther, the command also specifies that the ODE should be solved in the interval 0-1 and at the initial condition yo = 1 - The third line is just used to plot the solution in a graph. 

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