6.094 Introduction to programming in MATLAB [教程].ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Basic Scalar Operations Arithmetic operations (+,-,*,/) 7/45 (1+i)*(2+i) 1 / 0 0 / 0 Exponentiation (^) 4^2 (3+4*j)^2 Complicated expressions, use parentheses ((2+3)*3)^0.1 Multiplication is NOT implicit given parentheses 3(1+0.7) gives an error To clear command window clc Built-in Functions MATLAB has an enormous library of built-in functions Call using parentheses – passing parameter to function sqrt(2) log(2), log10(0.23) cos(1.2), atan(-.8) exp(2+4*i) round(1.4), floor(3.3), ceil(4.23) angle(i); abs(1+i); Exercise: Scalars You will learn MATLAB at an exponential rate! Add the following to your helloWorld script: Your learning time constant is 1.5 days. Calculate the number of seconds in 1.5 days and name this variable tau This class lasts 5 days. Calculate the number of seconds in 5 days and name this variable endOfClass This equation describes your knowledge as a function of time t: How well will you know MATLAB at endOfClass? Name this variable knowledgeAtEnd. (use exp) Using the value of knowledgeAtEnd, display the phrase: Hint: to convert a number to a string, use num2str At the end of 6.094, I will know X% of Matlab Exercise: Scalars secPerDay=60*60*24; tau=1.5*secPerDay; endOfClass=5*secPerDay knowledgeAtEnd=1-exp(-endOfClass/tau); disp([At the end of 6.094, I will know ... num2str(knowledgeAtEnd*100) % of Matlab]) Transpose The transpose operators turns a column vector into a row vector and vice versa a = [1 2 3 4+i] transpose(a) a a. The gives the Hermitian-transpose, i.e. transposes and conjugates all complex numbers For vectors of real numbers . and give same result Addition and Subtraction Addition and subtraction are element-wise; sizes must match (unless one is a scalar): The following would give an error c = row + column Use the transpose to make sizes compatible c = row’ + column c = row + column’ Can sum up or multiply elements of vec