Matlab Built-In Numeric Functions

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• Misc
  • Math Learning Center now open
    • M-F mid-day, M-Th evenings
    • Detailed schedule and more at http://www.geneseo.edu/math/mlc
• Questions?
• Built-In Matlab Functions
  • Section 2.2
    • Functions for radian vs degree trig functions (all of them, and inverses)
    • help command for functions
    • Start typing function name followed by tab to complete name
    • log for natural logarithm, log10 for base 10
  • Notation/terminology
    
  • Examples
    

    >> a = 3; b = 4;
    >> sqrt( a^2 + b^2 )
    ans =
         5
    >> sqrt( sin(pi/3) )
    ans =
        0.9306
    >> % log x + log y = log (xy)
    >> log(17) + log(34)
    ans =
        6.3596
    >> log( 17*34 )
    ans =
        6.3596
    >> floor( 3.4 )     % floor rounds down
    ans =
         3
    >> floor( 3 )
    ans =
         3
    >> floor( 3.9 )
    ans =
         3
    >> ceil( 3.2 )     % ceil rounds up
    ans =
         4
    >> round( 3.2 )    % round rounds to nearest
    ans =
         3
    >> round( 3.8 )
    ans =
         4
    >> round(3.5)
    ans =
         4
    >> factorial( 5 )   % compute factorials
    ans =
       120
    >> help log
      log    Natural logarithm.
        log(X) is the natural logarithm of the elements of X.
        Complex results are produced if X is not positive.
     
        See also log1p, log2, log10, exp, logm, reallog.
    
        Other functions named log
    
        Reference page in Help browser
           doc log
    
    >> log( 3, 27 )
    {Error using log
    Too many input arguments.}
    >> % Despite documentation to the contrary, specifying the base for a logarithm doesn’t seem to work
    >> log(27) / log(3)
    ans =
        3.0000
    >> help nthroot
     nthroot Real n-th root of real numbers.
     
        nthroot(X, N) returns the real Nth root of the elements of X.
        Both X and N must be real, and if X is negative, N must be an odd integer.
     
        Class support for inputs X, N:
           float: double, single
     
        See also power.
    
        Reference page in Help browser
           doc nthroot
    
    >> c = 3;
    >> 4ac
     4ac
      |
    {Error: Unexpected MATLAB expression.
    } 
    >> % Remember the asterisk when multiplying
    >> 4*a*c
    ans =
        36

• Arithmetic Lab
  • Hand-out
• Next
  • Scripts
  • Read sections 4.1 and 4.2 in textbook

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