CSE Midterm Study Sheet

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    Numbers

    Logicals

    Assignment Statement- assigning a value to a variable. Ex. A = 5

    If Statementsifconsequent statementsend

    If Else If Statements- these are like the if else statements except it has multiple

    conditions ex. if temp>100 disp(a) elseif temp>90 disp(b) elseif temp>80 disp(c)

    else disp(d)Relational Operators< > = == (less than, greater than, less than/equal to,

    greater than/equal to, the equal sign with the tilde in front just means not equal to,

    while the double equal sign means equal to)

    Logical Operators- && means and, double vertical line means or, the tilde means

    not)

    Pi3.14

    Sequences/Colon Notation1:5 (values 1-5) or 28:-9:1(start at 28, count by -9,

    dont go below 1)Vectora linear group of numbers arranged vertically or horizontally. Ex. [0 0 0

    0]

    Vector Masking(see example at bottom of page)

    Boolean Valueseither true or false

    Stringa sequence of characters

    For Loopseasier choice when you know how many times you want to repeat a

    set of instructions (see format at bottom of page)

    While Loops- runs the body repeatedly as long as the condition is true, or until thecondition is false. It tests the condition before doing the body for the first time. If

    the condition is false right away, the body will not be run at all (see format at

    bottom of page)

    User-Defined Functions- .m files that the user creates (did many in lab and HW)

    Built In Functions:

    sumcomputes the sum of the elements in a vector

    remremainder after division ex. rem(4,2)0 rem(8,3)2

    minmin(x) is the smallest element in x

    maxmax(x) is the largest element in xfloor(x) rounds elements of x to the nearest integers towardsneg. infinity.

    ceilceil(x) rounds elements of x to nearest integers towards pos. infinity

    linspacecalculates increments between values ex. linspace(1,10,3)1.0000

    5.5000 10.0000

    randgenerates one or more uniformly distributed random numbers(start

    w/#s b/w 0 and 1 but can be manipulatedby multiplying) ex. rand(1, 4)0.1270

    0.9134 0.6324 0.0975

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    sqrttakes the square root of a value

    randperm- p = randperm(n) returns a row vector containing a random

    permutation of the integers from 1 to n inclusive. Ex. randperm(6)[3 2 6 4 1

    5]

    strcmpcompares two strings for equality

    lengthdetermines the largest dimension of the matrix x

    size gives you the number of rows and columns of a variable ex. [ 1 2 3]would be 1 3

    findtells you where a vector is true. Ex. find([1 0 1 0)] 1 3

    dispdisplays the content of a variable

    zeros- will give you all zeros depending on what dimensions are given ex.

    zeros(2,3) will give a 2x3 vector

    oneswill give you all ones depending on dimensions given

    doublechanges x from a symbolic variable to a matrix variable

    charconverts input into to a stringclassreturns a string specifying the class of the object

    num2str- converts numbers to text strings ex. num2str(pi) = 3.1416

    str2numconverts strings to numbers

    *Array and Matrix are the same thing, everything in MatLab is a matrix

    *Ctrl + C to stop a never ending loop!

    *Two phases to a functions life: 1. When you define the function 2. When you call

    the function*vector masking ex.V = [10 20 30 40 50]; explanation:[10 20 30 40 50]

    M = [true false true true]; [true false true true] X

    V(M)

    ans =

    10 30 40

    *while loop setup while condition

    body

    end

    *for loop setup for variable = vectorbody

    end

    *function setup function [ output_args ] = Title( input_args )

    (body)

    end

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    Input Function- NUM = input(PROMPT) displays the PROMPT string on the

    screen, waits for input from the keyboard, evaluates any expressions in the input,

    and returns the value in NUM.

    fprintfdisplays something in a specific format(%g, %s, etc.)

    switch statement- The general form of the switch statement is:

    switch switch_expr

    CASE case_expr,statement, ..., statement

    CASE {case_expr1, case_expr2, case_expr3,...}

    statement, ..., statement

    ...

    OTHERWISE,

    statement, ..., statement

    END

    Cell array- cell(N) is an N-by-N cell array of empty matrices.cell(M,N) or cell([M,N]) is an M-by-N cell array of empty

    matrices.

    cell(M,N,P,...) or cell([M N P ...]) is an M-by-N-by-P-by-...

    cell array of empty matrices.

    Structure array- S = struct('field1',VALUES1,'field2',VALUES2,...) creates a

    structure array with the specified fields and values. The value

    arrays VALUES1, VALUES2, etc. must be cell arrays of the same

    size, scalar cells or single values. struct([]) creates an empty structure.More Functions:fopen- opens the file FILENAME for read access.

    FILENAME is a string containing the name of the file to be opened.

    fgetlRead line from file, discard newline character.

    fcloseclose the file

    feof - Test for end-of-file.

    ST = feof(FID) returns 1 if the end-of-file indicator for the

    file with file identifier FID has been set, and 0 otherwise.

    The end-of-file indicator is set when a read operation on the fileassociated with the FID attempts to read past the end of the file.