- Hour exam 2
- Next Monday, November 23
- Material since 1st exam, e.g., while, for, if, comparisons, logical operations, etc.
- Rules and format similar to 1st exam (notably open book, notes, computer for reference)
- Sample exam available on “Exercises” page
bisect( f, xl, xu, tolerance )
xm = (xl + xu) / 2 % In case (xu-xl)/2 > tolerance at the very beginning
while ( xu - xl ) / 2 > tolerance
xm = (xl + xu) / 2
if f(xm)*f(xl) < 0
xu = xm
else if f(xm) * f(xl) > 0
xl = xm
else % f(xm) * f(xl)= 0
xu = xm % Force loop to exit
xl = xm
end of while
return xm- Tolerance used to stop is on how far x is from actual root
- Sections 13.1 and 13.2 summary
- General syntax
if condition1 statements1 elseif condition2 statements2 … else statements end - Alternative multiway conditional
if condition1 statements1 end if condition2 statements2 end …- But note that this can execute multiple code blocks if
multiple conditions are true, whereas the form with
elseifandelseonly executes the code that goes with the first true condition
- But note that this can execute multiple code blocks if
multiple conditions are true, whereas the form with
- General syntax
- Examples
% Demonstrations of Matlab's "if" statement %% Classify numbers as positive vs negative vs zero x = input( 'Enter a number ' ); if x > 0 fprintf( 'Yay, you found a positive number!\n' ); elseif x < 0 fprintf( 'Oh no, you gave me a negative number!\n' ); else fprintf( 'Finally, you gave me zero\n' ); end %% Only divide by x if x not equal to 0 x = input( 'Enter a number ' ); if x ~= 0 fprintf( 'Reciprocal of %f is %f\n', x, 1/x ); end
- Work on bisection lab