1 / 10

MATLAB While Loops

MATLAB While Loops. ENGR 1181 Presentation by Annie Abell. Today’s Topics. Reminders about while loops Useful functions for while loops Examples of simple and complex while loops. Reminders About While Loops.

minnie
Download Presentation

MATLAB While Loops

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MATLAB While Loops ENGR 1181 Presentation by Annie Abell

  2. Today’s Topics • Reminders about while loops • Useful functions for while loops • Examples of simple and complex while loops

  3. Reminders About While Loops • While loops must have a conditional expression, and the conditional expression must have at least one variable. • Conditional variables must be "initialized" before the loop. • The conditional variable must advance with each pass. (Otherwise the loop will continue indefinitely!) • "Ctrl + C" will terminate execution of an indefinite loop.

  4. Function: rem() This function checks for a remainder when dividing x by y. rem(x,y) Ex: rem(x,3)will check if the value of xis divisible by 3.

  5. Function: tic/toc • tic and toc are timing functions that monitor elapsed time in your program • tic starts a stopwatch that runs in the background • toc returns the elapsed time since the tic command • The value of toc can be assigned to a variable

  6. Example: Simple While Loop Note: • conditional variable is initialized • variable advances each time • one end corresponds to if • one end corresponds to while a=0 while a<10 a=a+1if (a==5) continueenddisp(a)end 1234678910

  7. Example: Complex While Loop Task Steps Initialize variables: sq & # Loop while sq < 3325 Advance # by 3 in each pass Check if # is divisible by 5 If yes, square the # Repeat loop until sq >3325. Loop stops & # value will give us the smallest integer to meet conditions Write a program that will use a while loop to find the smallest number divisible by both 3 and 5, with the square of the number greater than 3325.

  8. Example: Complex While Loops n=0; sq=0; %initialize variables: # & square whilesq<=3325 %loop until square >3325n=n+3 %advance # by 3 each pass if rem(n,5)==0 %check if # is divisible by 5sq=n^2; %if yes, square #end %end if statementend %end while loop disp(n) %display the # that meets criteria

  9. Tic/Toc Example N=input('\nPlease enter a large value for N: '); ticfori=1:N sqroot= sqrt(i);end SqrtTime=toc; fprintf('\n\nIt took MATLAB %f seconds to calculate %i square roots\n', SqrtTime, N) %obtain value for N %start stopwatch%loop to calculate all of the square roots %obtain elapsed time %statement reporting how long it took to calculate the sq roots

  10. Questions?

More Related