KURSUS MATLAB ONLINE Skripsi, Tesis, DISERTASI 081219449060

• Today's lecture explores these two areas as applied to Matlab References:        For Engineers (Ch. 1)                                                             User's Guide (Ch. 1, 3, 9)                                                             Mastering (Ch.. 2, 5, 10) 16.1       Variables • Programs model some aspect of the real world data objects (variables) which the program employs & manipulates thus represent some object or concept in the real world • In Matlab a variable has -              name • an identifier (or handle) • selected to indicate what real world object it represents -              data type • what values can the variable have? • what operations can be performed upon it? • all Matlab variables have a default type (class) which is a vector of real numbers 16.2       Identifiers • Names created by the programmer to represent various objects (quantities) in the program • Syntax: -              No white-space (e.g., class total is not valid) -              Must start with a letter (e.g., k9 is valid, 2tango is not) -              Can be composed from letters, digits, & underscores (e.g., class_total is valid, class-total is not valid) -              Can have up to 31 characters (those beyond 31 are ignored) -              Is case sensitive (e.g., highscore and highScore are two different variables) • Avoid pre-defined function and reserved words (e.g., "for", "mean" etc. as these replace the built-in functions) 16.3       Meaningful Identifiers • Identifiers should communicate their purpose (meaning – what they represent) clearly and precisely without undue verbosity 16.3.1    Some Examples s1                          vs. student1 the_first_student_on_the_course  vs. first_student N, k, m, n                                           (OK for maths) student1 & student2        (try to avoid similar names) high_score          or highScore                      (two conventions for composite ids) 16.4       Weak Typing • Unlike many 3rd generation languages, Matlab is extremely weakly typed: - no declaration of variables before use - one major type of data (variable) with a few special cases & additions • by default everything is a vector (1-dimensional array) of real numbers • single values (scalars) simply a vector with a single element e.g.

single = 9.3;        % A vector with one                         % element                                                                                 % i.e., a scalar                               countDown = 10:-1:1;     % A vector:                              % 10, 9,…,1                               average = mean(values);                         % May be a scalar,                                                                      % vector or matrix 16.5       Implications of Weak Typing • This approach has several advantages & dis-advantages: -              very powerful things may be expressed (& hence solved) very easily, but there is little "protection" 16.5.1    Advantages • Shorter initial learning curve: can write useful programs nearly immediately • Implicit vectorisation (everything treated a a vector) leads to simpler and more intuitive programs 16.5.2    Disadvantages • No protection for users from simple errors (e.g., typed results=x+y instead of result=x+y;) • Single statements become harder to understand (e.g., does average=mean(values); produce a scalar, vector or array?) • More difficult to closely match real-world objects 16.6       Special (Built-in) Constants & Variables • Matlab has a number of built-in constants and variables Name    Description ans         Default destination for results pi            Ratio of circle circumference to diameter eps         Smallest number such that x+eps ‡ x flops      Floating point operations performed int          Infinity Nan or nan          Not-a-number (undefined) I & j        √-1  (square root of –1) nargin    Number of arguments supplied to a function nargout Number of arguments output by a function realmin The smallest usable positive real number realmax               The largest usable positive real number † After Version 5.0 User's Guide, Prentice Hall, 1998 16.7       Complex Numbers • Matlab implicitly supports complex numbers - no requirement for special functions to manipulate • For example EDU» z1=sqrt(-4)+3 z1 =    3.0000+ 2.0000i EDU» z2=z1*(1-i) z2 =    5.0000- 1.0000i EDU» z3=5.6*sin(1.55)*i z3 =         0+ 5.5988i EDU» r1=imag(z3)  r1 =     5.5988 EDU» z4=mean([z1 z2 z3]) z4 =    2.6667+ 2.1996i • Note: -              mathematical and built-in function usage is exactly the same as for non-complex -              complex expressions yield complex values 16.8       Nan & inf • Mathematical operations can often yield undefined results or those beyond the storage capability of the machine • In many languages these type of operation (e.g., division by zero) cause the running program to crash - not particularly desirable • Matlab has two special "constants" which are substituted when such operations occur: Nan        Not A Number inf                         Infinity -              this allows recovery or continuation • For example: EDU» undef=0/0 Warning: Divide by zero.

Kami ada di Jakarta Selatan. KAMI MEMBERIKAN KURSUS MATLAB ONLINE - HUBUNGI MASTER ENGINEERING EXPERT (MEE) 081219449060.  Kami membuka kursus Matlab untuk pemula dan mahasiswa atau insinyur yang ingin memperdalam Matlab dan menerapkan dalam bidang teknikal, engineering, rekayasa, dsb. Format bimbingannya tugas-tugas yang bisa membantu Skripsi, Tesis, DISERTASI Bimbingan dilakukan secara online bisa lewat WA atau email Dijamin Bisa, atau bisa mengulang kembali. Kami juga dapat membantumembuatkan aplikasi atau program matlab/lainnya. Anda akan dilatih oleh Tim Profesional - HUBUNGI MASTER ENGINEERING EXPERT (MEE) 081219449060.   Email: kursusmatlab@gmail.com undef =    NaN EDU» big=1/0 Warning: Divide by zero.