Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Math in the News: 8/29/11


Published on

In this issue of Math in the News we look at how to develop computer models for tracking the path of a hurricane.

For more media resources go to

Published in: Education, Technology
  • Be the first to comment

  • Be the first to like this

Math in the News: 8/29/11

  1. 1. 8/29/11
  2. 2. Hurricanes <ul><li>The specific path that a hurricane takes can’t be accurately predicted because of the many variables involved. </li></ul><ul><li>But the general path that a hurricane takes is in a northwestern direction. </li></ul>
  3. 3. Hurricanes <ul><li>One way to model the behavior of a hurricane is to use a “random walk” simulation. </li></ul><ul><li>Imagine an ant on a coordinate grid and the random walk it would take across it. </li></ul>
  4. 4. Hurricanes <ul><li>You can create a random walk using an Excel spreadsheet. </li></ul><ul><li>The data in the table, represented in the graph, was generated using a random number formula. </li></ul>
  5. 5. Hurricanes <ul><li>Add two column headings, x and y, to A1 and B1. </li></ul><ul><li>Start at the origin. Enter 0 in A2 and B2. </li></ul><ul><li>Enter this formula (shown for A3) in subsequent rows: </li></ul><ul><li>=A2+RANDBETWEEN(-2,2) </li></ul><ul><li>Do the same for Column B. </li></ul><ul><li>Graph the data. </li></ul>
  6. 6. Hurricanes <ul><li>But this random walk needs to be a bit less random if we want the path to generally go along a northwest path. </li></ul>
  7. 7. Hurricanes <ul><li>If we place an x-y coordinate grid as shown on a map, then the random path should start in quadrant 4 and move along a negatively sloped path. </li></ul>
  8. 8. Hurricanes <ul><li>In other words, the randomization should favor a step to left than one to the right, and a step upward than one downward. </li></ul><ul><li>How can we influence the randomization this way? </li></ul>
  9. 9. Hurricanes <ul><li>Add two column headings, x and y, to A1 and B1. </li></ul><ul><li>Input the coordinates (10, -10) in A2 and B2. </li></ul>
  10. 10. Hurricanes <ul><li>Add this formula to cell A3. </li></ul><ul><li>Then input this formula into cell B3 </li></ul>
  11. 11. Hurricanes <ul><li>Copy and paste the formulas in cells A3 and B3 to enough cells to create 20 ordered pairs. </li></ul>
  12. 12. Hurricanes <ul><li>Graph the data. </li></ul>
  13. 13. Hurricanes <ul><li>Overlay a map of the region to see the simulated path of the hurricane. </li></ul>
  14. 14. Hurricanes <ul><li>Run different simulations to model different paths. </li></ul>
  15. 15. Hurricanes <ul><li>Tweak the randomization formulas to affect the amount of northern and western tracking. </li></ul>
  16. 16. Hurricanes <ul><li>Scientists use sophisticated computer models to predict the path of a hurricane. </li></ul><ul><li>But because of the many variables involved, predicting a hurricane’s path with a high degree of accuracy is difficult. </li></ul>