ISTA 352 - Images: Past, Present, and Future - Fall 2012

Assignment Four (A)

Note change of format---this assignments has been broken into two smaller units

Due: Late (*) Tuesday, November 06.

(*) "Late" means that the instructor might start grading by 8AM Wednesday. Once the instructor starts grading, no more assignments will be accepted.

5 points

This assignment should be done individually

 

Programming is not relevant for this version of the assignment.

 

You can do the programming parts of this assignment in any language you like, although if your results are anomalous, and the grader does not speak the language you use, they may be less able to quickly figure out what the problem is and give you reasonable part marks.

 

Regardless of what language you use, please follow the instructions linked here  carefully.

 

Deliverables

Deliverables within questions are flagged with ($).

 

This assignment has 2 regular questions. The first regular problem is worth 2 points, and the second one is worth 3, for a total of 5.

 

 

1. (+) This link points to a clip of Edward Tufte talking about a famous figure by Charles Joseph Minard (linked here). Listen carefully to what Tufte has to say about design. For each design principle you can identify, write a few sentences saying what it is. Label them by “The principle”. Follow each identified principle with “The reasoning” where you describe briefly how the principle relates to natural human activities and goals. Try to put things in your own words as best as possible and provide added value to the discussion if you can. If you need to use more than a few words from Tufte, put them in quotation marks ($).

 

2. (++) In the simplified contour map below, the coordinates of some of the points are A=(3,10), B=(21,10), C=(13,7), D=(13,12.5), and E=(24,7).  You can assume that the outer contour is 200m above sea level, and that the altitude of point C is 450m above sea level.

 

a) Sketch a cross-section showing the altitude as a function of X going from A to B ($). Do the same for going from C to E ($). Finally, do the same for C to D (here altitude should be a function of Y) ($).

b) Compute an approximation of the gradient vector at F in terms of X and Y ($). You can make use of the assumption that FH is about 2.5cm and FG is about 2cm. Reproduce that section of the figure in a sketch, showing the gradient direction ($). Does it match your intuition of where it should go ($). Finally, do the same for the gradient at point I, supplying the same three deliverables ($).

c) Estimate the average angle of the slope for CD and CE ($).To do this problem you will need to brush off your high school trigonometry. Note that the distances that you can derive from the coordinates are the projection onto a plane that is parallel to sea level. These are different than the distances that you would travel in 3D following the lines. For modest bonus marks, compute the actual distance traveled along CD and CE if you were climbing the mountain.

 

Challenge problems

Challenge problems are not required, but can be exchanged for non-challenge problems, or done for modest extra credit. They provide flexibility for students who are especially interested in the subject, and who are comfortable with their understanding of the basics. They can be difficult and often require some math skills that are not pre-requisite for this course. I recommend being careful about spending too much time on them.

 

No challenge problems for this version.

 

 

What to Hand In

Consult the instructions linked here for conventions for preparing and handing in assignments. In 2012, hand in assignments via email to Kyle Simek (ksimek@email.arizona.edu).