Defining a function:

1

• Defining a function
• Open an m-file and write the following statement.
  
• function OUTPUT1, OUTPUT2 function_name(INPUT1
  , INPUT2)
• Statements
• Statements
• Save the m-file as the function name. The
  following statement,
• gtgt function_name(INPUT1, INPUT2)
• in the command window gives the output
  corresponding to the inputs given .
• When you call an M-file function from the
  command line or from within another M-file,
  MATLAB parses the function and stores it in
  memory. The parsed function remains in memory
  until cleared with the clear command or you quit
  MATLAB.

2

• Example of a function MFILE
• function output1,output2 matlab(inp1,inp2)
• output1inp1inp2
• output2inp1/inp2
• Save the m file as matlab.m.
• Command window
• gtgt a bmatlab(6,3)
• a 18
• b 2

3

• rand Uniformly distributed random numbers and
  arrays
• Syntax Y rand(n) ,Y rand(m,n)
• Description The rand function generates arrays
  of random numbers whose elements are uniformly
  distributed in the interval (0,1).
• To generate uniform random numbers with minimum
  and maximum bounds other than 0 and 1
  respectively, use the following formula
• x ((b-a) Y) a with "Y" being the variable
  from above and "b" representing the upper bound
  and "a" representing the lower bound.     

4

• randn
• Syntax Y randn(n) Y randn(m,n)
• Description The randn function generates arrays
  of random numbers whose elements are normally
  distributed (Gaussian) with mean 0 and variance
  1.
• To generate 1000 Gaussian random numbers with
  something other than a zero mean and a standard
  deviation (STD) of 1 (both default values), use
  the following formula
• (STD randn(1000,1)) MEAN  

5

• A1 2 3 4 5 Mean mean(A) mean of A
• Median median(A) median of A
• Standard deviationstd(A) standard deviation of
  A.
• randperm(10)
• gtgtans 8 2 10 7 4 3
  6 9 5 1

6

• HIST plots a histogram
• hist(y) draws a 10-bin histogram for the data in
  vector y. The bins are equally spaced between the
  minimum and maximum values in y.
• hist(y,nb) draws a histogram with nb bins.
• hist(y,x), if x is a vector, draws a histogram
  using the bins specified in x.

7

• Generate bell-curve histograms from Gaussian
  data.
• gtgtx -2.90.12.9 y randn(10000,1)
  gtgthist(y,x)
• hist(y) draws a 10-bin histogram for the data in
  vector y. The bins are equally spaced between the
  minimum and maximum values in y.
• hist(y,nb) draws a histogram with nb bins.
• hist(y,x), if x is a vector, draws a histogram
  using the bins specified in x.