Predefined MATLAB

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PredefinedMATLAB Functions
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Matlab Functions

• MATLAB provides a built-in library of functions
  that include
• Exponential
• Logarithmic
• Trigonometric
• Inverse Trigonometric
• Hyperbolic
• Statistical
• And many more

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Matlab Functions

• Here is a summary of elementary math functions
• abs(x) computes absolute value of x
• sqrt(x) calculates square root of x
• round(x) performs statistical rounding of x
• fix(x) rounds x towards zero
• floor(x) rounds x down
• ceil(x) rounds x up
• sign(x) returns the sign of x
• rem(x,y) returns the remainder of x/y

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Matlab Functions

• Here is a summary of exponential, logarithmic,
  and trigonometric functions
• exp(x) calculates ex
• log(x) computes the natural logarithm of x
• log10(x) computes the logarithm base 10 of x
• log2(x) computes the logarithm base 2 of x
• sin(x) returns the sine of x
• cos(x) returns the cosine of x
• tan(x) returns the tangent of x

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Matlab Functions

• Here is a summary of inverse trigonometric and
  hyperbolic functions
• asin(x) returns the arc sine of x
• acos(x) returns the arc cosine of x
• atan(x) returns the arc tangent of x
• sinh(x) computes the hyperbolic sine of x
• cosh(x) computes the hyperbolic cosine of x
• tanh(x) computes the hyperbolic tangent of x

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Matlab Functions

• Here is a summary of statistical functions
• min(A) Finds the minimum value in array A
• max(A) Finds the maximum value in array A
• mean(A) Finds the average of the values in A
• median(A) Finds the median of the values in A
• std(A) Calculates the standard deviation in A
• erf(x) Evaluates the error function at x
• rand(N) Forms an NxN matrix of uniformly
  distributed random numbers
• randn(N) Same but normally distributed

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Matlab Functions

• Here is a summary of matrix functions
• sort(A) Sorts the elements of A ascending
• sum(A) Adds the values in A
• prod(A) Multiplies the values in A
• length(A) determines the largest dimension of A
• size(A) returns the number of rows and columns
  of A

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Matlab Functions

• These are some special characters
• eps Smallest recognized difference
• i or j Imaginary number
• Inf Infinity
• Nan Not a number
• pi constant ?

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Matlab Functions
For example, create the following range
variables X 0.0pi/1002pi Y1 cos(X) Y2
sin(X) Y3 2cos(2X) Y4 2sin(4X) Plot(X,Y
1,X,Y2,X,Y3,X,Y4)
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Matlab Functions
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Matlab Functions
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Matlab Functions
Solve the following equations For ?1 45º and
?2 ?/2.345 A 103/cos(?1) B sqrt( 10 20
30 cos(?1) sin(?2)) C tan(?1) cos(?2)
sin(?2/3.14) D (1-cos(?)) (1-sin(?1)) -2pi-1.1
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Matlab Functions
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Matlab Functions

• Solve the following equations
• Theta 0 to 2pi with a step of pi/100
• Y1 1.2sin(Theta)
• Y2 2.4sin(Theta pi/4)
• Y3 cos(Theta pi/4) sin(2Theta)
• Plot all three solutions on the same graph
• Add title, axis labels, and grid.
• Save the workspace as Lab08_01.mat
• Save the plot as Lab08_01.fig

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Matlab Functions

• Solve the following equations
• x -5 to 5 with a step of 0.1
• Plot the solution
• Add title, axis labels, and grid.
• Save the workspace as Lab08_02.mat
• Save the figure as Lab08_02.fig

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Matlab Functions
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Matlab Functions

• Matlab commands can also be saved in sequence
  using the concept of M-files
• Click on File -gt New -gt M-File

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Matlab Functions

• Enter the following commands
• clear, clc
• low_speed 5
• high_speed 10
• seed 24
• rand(seed,seed)
• t 0103600
• t t / 3600
• num length(t)

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Matlab Functions

• continue
• speed (high_speed - low_speed)rand(1,num)
  low_speed
• table t,speed
• Save windspd.dat table ascii
• plot(t,speed)
• xlabel(time hr)
• ylabel(speed mph)

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Matlab Functions

• continue
• Add comments to your M-file
• Save the file as Windspd.m
• Run the file by clicking Debug -gt Run
• Save the figure as Windspd.fig

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Matlab Functions
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Matlab Functions
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Matlab Functions