Scripts and Functions

The programs written in the language of MATLAB should be saved with the extension of m , from where the name of m-file comes. If you use the editor of MATLAB, it automatically saves your files with the w extension. Otherwise, be sure to save them with the m extension. M-files can be in the form of scripts ondi functions and could be executed in the MATLAB workspace. 

A script is simply a series of MATLAB commands that could have been entered in the workspace. When typing the name of the script, the commands will be executed in their sequential order as if they were individually typed in the workspace. For example, let us calculate the volume of an ideal gas as a function of pressure and temperature. Type the following commands in the editor and save it as myscript.m  

The symbol % indicates that this line contains comments. The % sign, and what comes after it in that line, will be ignored at the time of execution. Return to the MATLAB command window and type  

A practical method for beginners to create a script is using diary. You can start creating a diary by  

Then you start typing your statements in the workspace one by one. For example, you can type the statements of the script developed above, see the results at each step, and make corrections if necessary. When you got your desired results, close the diary  

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Apart from performing operations, MATLAB is a programming language. Its operation is based on the use of. m files that can be divided in two classes, scripts and functions. A script is basically a number of operations that we want to perform in a certain sequence. It is required that they are in order so that the variables and parameters are already defined. We can use them as executables and within them, we can also call other subrogate scripts that contain other operations... 

MATLAB search path is an ordered list of directories that MATLAB searches to find script and function M-files stored on disk. The MATLAB s path is defined from the File menu via clicking on the Set Path sub-menu, as shown in Figs. 3.1 and 3.2a. 

The following suggestions are either necessary or highly recommended for the effective use of MATLAB script and function M-files ... 

Biopipe [OS2] is a framework for running bioinformatics workflows and is deployable as an extension to the Bioperl project library [OS4]. It borrows heavily from the Ensembl pipeline project [OS7]. Potential users of the system should be comfortable coding Perl scripts and actually reconfiguring a Perl installation to add the necessary prerequisites. The user also needs to deal with coding raw XML to compose and configure a workflow and setting up the mySQL database that is required for the system to function. 

The Species File Group (SFG) has developed a template that contains the basic database table structure as well as the stored procedures, user-defined functions and views used by Species Files. The template is used as the starting point for new Species File databases (SpeciesFile-Databases ). Species File is a MS Visual Studio application. Progranmiing for Species File is done with Visual Studio.NET. The Active Server Pages (ASP) use Visual Basic Script and client side programming is done using JavaScript. 

The accompanying CD-ROM contains MATLAB 5.0 (and higher) source code for more than 60 examples, methods, and function scripts covered in the book. These programs are compatible with all three operating systems Windows , MacOS , and UNIX . 

Shown below is a MATLAB script (no function heading) file that prompts the user for two initial guesses for f(0). These guesses are used by the secant method to converge the right and boundary conditions, which is 7(1) = 0. 

Inspection An examination of the item against applicable drawings and other documentation to satisfy compliance witli stated item requirements. Hardware must have applicable tolerances to satisfy form, fit, and function with other components. Software modules must satisfy test scripts and check sums to prove that they will run in larger programs, as well as with other software modules. 

The ASCII input file includes elements of a scripting language. Thus, the input can contain variables, loops, and procedures. This is one of the aspects of the program that makes it possible to do very complex calculations. The documentation describes the input options, but does not discuss when and why they should be used. The user must have a solid understanding of ah initio theory in order to correctly utilize many of the functions in this program. It is very powerful, but not for beginners. 

Script file examp77.m plots the closed-loop step responses of both the continuous system and discrete system (see Figure 7.21). In the latter case the plant pulse transfer function uses zoh, and the compensator is converted into discrete form using... 

The continuous and discrete closed-loop systems are shown in Figures 7.22(a) and (b). The digital compensator is given in equation (7.128). Script file examp78.m produces the step response of both systems (Figure 7.25) and prints the open and closed-loop continuous and pulse transfer functions in the command window... 

The user is able to customize the transform setup resource file to include as many custom scripts or unit transforms as desired for a particular application. In addition, the user can improvise operations on the fly. If the analyst decides to try plotting the data as a function of a reciprocal log, he takes the log and then reciprocal of the x-axis. If he decides to make this a regular option, he can enter it in the transform setup list under any name desired. Next time the transform option is called he will be able to select that operation by choosing it from the list under the name saved under. 

The automations are often controlled by scripts that define the protocols, the methods, the timing of an automation and the interaction of the methods and automation or geometry settings. The easy way to expand scripts with user functionality enables the research user to implement special functionality to support nonstandard hardware and create complex laboratory-built automation scenarios. 

This level of control requires a controlling script from the instrument vendor and is for more serious programmers. Direct HPLC control by the MS and multiple staggered LC capabilities provided by several autosampler and instrument vendors fulfill the function but may limit the hardware used or require purchase of software/hardware. 

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