## Homework for METR 5803, Spring 2016

### Assignment 1

*Assigned 26 January, due 2 February*

Use the number of F1+ tornadoes in the United States per
month from 1954-2014. The data are available as text files
here. Note that the years are the first column.

Calculate the following quantities for each month:

- Mean
- Median
- Sample Standard Deviation
- Interquartile Range
- Median Absolute Deviation
- Percentiles at
- 0.10
- 0.25
- 0.75
- 0.90

Comment on any differences between the parametric and
non-parametric approaches to examining these datasets.

### Assignment 2

*Assigned 2 February, due 11 February*

Evaluate the SPC Day 1 (12 Z) convective outlooks from 1973-2010. The data are available as csv files
here. Note that the years are the first column, the slight risk are the next 4 columns, and the moderate risk are the final 4. Also, the slight and moderate risk are the same for 1973 and 1974. Things were redefined in 1975 to make them different.

Calculate the following quantities for each year for each outlook:

- POD
- FOH
- CSI
- POFD
- Bias
- Heidke Skill Score
- Hanssen-Kuipers Skill Score

You don't need to show me the table, although I won't be upset if you do. What you need to do is to plot time series of the 6 quantities. You can put more than one on a single graph as long as you retain enough range in the vertical scale to see what's going on. That is, if one of them varies between 0.9 and 1 and another varies between 0 and 0.1, putting them on the same scale is not very easy to read. Also, plot a time series on a performance diagram (POD-y axis, FOH-x axis).

You can also create additional, *informative* graphics that will allow you to address the basic questions of:
- How has SPC performance changed over time?
- How are the slight risk and moderate risks related to each other (e.g., are there different apparent goals for them?
- What information that's not included in the tables might impact your assessment of the performance?