Notes

Outline

The MatLab Language Mathematics Laboratory The MathWorks www.mathworks.com

General Comments – “%” in first column Result Control - “;” at the end "x=5" x = 5 "x=7;“ "x" x = 7

General (continued) Range Operator "x=3:2:13" x = 3     5     7     9    11    13 Line Continuation - three periods Directory "dir" announ~2.doc mathview.doc matlab_6.doc matlab~2.doc intro.m matlab.doc matlab~1.doc vector.m announ~1.doc language.m   matlab1.doc  matlab~1.ppt

General (continued) Print Working Directory "pwd" ans = E:\DOC\JEFF\COURSES\BEI\SHORTC~1\MATLAB Change Directory - cd "cd .." "pwd" ans = E:\DOC\JEFF\COURSES\BEI\SHORTC~1

General (continued) "cd matlab" "pwd" ans = E:\DOC\JEFF\COURSES\BEI\SHORTC~1\MATLAB

Scalars, Vectors, and Matrices Creating a row vector "X=[1,2,3] or X=[1 2 3] X = 1     2     3 Creating a column vector "Y=[1;2;3]" or "Y=[1                                 2                                 3]" Y = 1 2 3

Vector / Matrix Operations "Z=[y,2*y,3*y]" creates ? Z = 1     2     3 2     4     6 3     6     9

Indexing "Z(2,3)=?" ans = 6 "W=Z(1:2,2:3)" W = 2     3 4     6  "W=Z(:,2)" W = 2 4 6

Indexing (Continued) "W=Z(2,:)" W = 2     4     6 "Z(2,:)=[6,4,2] does ?" Z = 1     2     3 6     4     2 3     6     9 "Z(2,:)=[ ] does ?" Z = 1     2     3 3     6     9

Matrix Operations A+B  - Addition, element by element "ZZ=[1,1,1;2,2,2]" ZZ = 1     1     1 2     2     2 "W=Z+ZZ" W = 2     3     4 5     8    11

Matrix Operations (Continued) A'   - Transpose A*B  - Matrix Multiplication "ZZ=ZZ' " ZZ = 1     2 1     2 1     2 "W=Z*ZZ" W = 6    12 18    36

Matrix Operations (Continued) A.*B - Element by Element Multiply Also: A/B, A\B, A./B, A.^2 Reserved Symbols Scalars: pi, i, j, inf, NaN, clock, date, ans "x=pi" x = 3.1416 "x=i" x = 0 + 1.0000i

Scalars (Continued) "x=j" x = 0 + 1.0000i

Matrices: zeros, ones, eye "zeros(3,5)" ans = 0     0     0     0     0 0     0     0     0     0 0     0     0     0     0

Matrices (Continued) "ones(5,3)" ans = 1     1     1 1     1     1 1     1     1 1     1     1 1     1     1

Matrices (Continued) "eye(4)" - the identity matrix ans = 1     0     0     0 0     1     0     0 0     0     1     0 0     0     0     1

Relational Operators "<"  - less than "<=" - less than or equal to ">"  - greater than ">=" - greater than or equal to "==" - test for equality "~=" - not equal to "&"  - AND "|"  - OR "~"  - NOT

Control Flow (If) if x>5 & x<8 ------- ------- elseif(x>=8) ------- ------- else ------- end

Control Flow (For Loops) for k=7:21 ------- ------- end

Control Flow (While Loops) k=1; while k=<10 ------- ------- k=k+1; end