Plot command, MATLAB

Figure 3.6 The plot of f(x) using the MATLAB plot command. 

These indicate the limit of our successful numerical BVP integrations near the bifurcation points. In between the x and o marks on the middle branch, the curve is drawn using interpolation of our successful BVP solutions data, while in between two adjacent x or two adjacent o marks, the curve is drawn by extrapolating nearby computed function data. This is done automatically by MATLAB s plot commands. 

The training set will be used to calculate the multivariate mean and variance-covariance matrix however, before calculating these parameters, we will graphically examine the training set to see if it contains measurements that are approximately normally distributed. This can be accomplished by several methods, the simplest being to plot histograms of the individual variables. Use the MATLAB hist command to... 

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 If you do not define the color attributes, then by default MATLAB currently cycles through the colors blue, green, red, cyan, magenta, yellow, and black when creating multiple lines with a plot command, as shown in Fig. 1.16b. 

The output of clicking this choice of plots is shown in Fig. 5.8. This is how it appears in MATLAB s Command ... 

Second, create callmultiode.m (a script M-file) that contains the initial value for eachy the lower and upper limit for integration the options attributes, which is a structure of optional parameters that change the default integration properties a call to the MATLAB ode45 solver and a plot command fory as a function of t. Figure 7.7 embodies such a list of commands. 

Additional plot commands in MATLAB are loglog for log-log plots, and semilogx and semilogy for semi-log plots, such as the Bode plots used in Chapter 14. 

MATLAB s plotting capabilities are such that professional quality graphs can be generated. The commands for producing graphs vary from the very simple to the quite complex. In this coverage, only relatively simple plot commands are discussed, but more complete discussions are readily available. 

After entering the riocf ind () command, MATLAB will prompt us to click a point on the root locus plot. In this problem, we select the intersection between the root locus and the imaginary axis for the ultimate gain. 

For each session, we put the most important functions in a table for easy reference or review. The first one is on the basic commands and plotting. Try the commands as you read. You do not have to enter any text after the "%" sign. Any text behind a "%" is considered a comment and is ignored. We will save some paper and omit the results generated by MATLAB. If you need to see that for help, they are provided on our Web Support. There is also where we post any new MATLAB changes and upgrades. Features in our tutorial sessions are based on MATLAB Version 6.1, and Control System Toolbox 5.1. 

We can issue multiple commands on the same line separated by commas. What makes MATLAB easy to learn is that we can add goodies one after another. We do not have to worry about complex command syntax. We can also do logarithmic plots. Try enter "help semilogx, semilogy, or loglog." We ll skip them because they are not crucial for our immediate needs. 

The first graphical representation using MATLAB software is that of a two-dimensional contour surface plot of the data from Table 75-1 [2], This Figure 75-3 plot can represent multiple levels of j-axis data (absorbance) by the use of contours and color schemes. The MATLAB commands for generating this image are given in Table 75-2 where A represents the raster data matrix shown in Table 75-1. 

Table 75-2 MATLAB commands for generating a contour plot of data matrix A found in Table 75-1...

Table 75-4 MATLAB commands for generating a 2-D contour plot over a 3-D surface plot...

The last two codes contain many intricate and useful plotting and contour commands that are self-explanatory when one uses the MATLAB help. .. function for the MAT-LAB graphics commands meshgrid, surface, contour3, xlabel, ylabel, title, colormap, etc. Students should study these graphics commands of MATLAB in order to be learn how to display the easily computed numerical data well. Please refer to MATLAB help. ... 

Figure 4.29 was obtained via the MATLAB code hetcontbifmultiK.m which we have derived from hetcontbif range. m. It features an auxiliary plot of the exponential curve to find the proper axes limits for the plot first. Note also the elaborate sequence of legend commands that we use. 

A detailed reading of the fluidbed.m program reveals that a hold on MATLAB command is put onto the plot that is never released. This helps us draw multiple trajectories onto one 3D plot such as in Figure 4.34. Note that Figure 4.34 depicts the actual MATLAB output after a suitable rotation as explained before on p. 186. If the user wants... 

Table 12.1 gives a MATLAB program that generates a W plot for the Wood and Berry column. After the four transfer functions are formed for the process and the two transfer functions are formed for the controllers, they are evaluated at each frequency using the polyval command. The identity matrix is formed by using the eye siie(g)) command. Then the W function is calculated at each frequency using the wnyquist nw)-— I +det eye(size(g))+g gc) command. This calculation is a good example of how easy it is to handle complex matrix calculations in MATLAB. 

The MATLAB Command Window for Example 15.4 is shown in Figure 15.12. The plot of volume versus x is shown in Figure 15.13. 

Let us now discuss the MATLAB commands that commonly are used when plotdi data. The plot (Xf y) command plots y values versus xvalues. You can use various line types, plot symbols, or colors with the command plot (x,y, s), where s is a charaaer string that defines a particular line type, plot symbol, or line color. The 8 can take on one of the properties shown in Table 15.12. 

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