Post on 19-Feb-2016
description
Visualization feedbackExcel recap (PV and FV)
Absolute addressesColbert bumpElectoral map
Homework: PostingsPROPOSALS. Presentations
Visualization: general
• Good effort (from most of you). Doing something means• Points (because I'm generous)• Something for me to react
• Visualization means communicating something, hopefully doing it well…
Specifics• Lines versus points.
• Lines do help us connect. • But, do NOT use lines when they have no
meaning.• Across categories
• Bubble graph. Demonstrate.• You need 3 numbers for each data point.• Gapminder added category of country,
time dimension. Show. • What about lines here?
Specifics, cont.• States, other
• Summarize by number of states?• Population?
• Color, including printing in black and white• LOOK AT IT!!! Can you distinguish
categories, lines, dots, etc.• Investigate options.• Making things bigger helps.
Tools• There are tools for producing visualizations
and graphics.• Word cloud
• Show bilingual example• http://www.wordle.net/• http://worditout.com/word-cloud/make-a-new-o
ne
• http://piktochart.com/
Source?
Worditout cloud program
Postings: general
• Do look at the posting after you have made it. You can edit!
• Content has been good• …. But many are not participating.
General
• Data source, which includes format of questions on survey
• Distributions• Comparisons: what's the difference?• Dimension can be applied to categories,
factors.• Definitions• Be skeptical AND/BUT allow the findings to
contradict your preconceptions…
Recap on mortgages
• Mortgage: pay (fixed) amount for whole term of mortgage.– Some goes towards interest– Some goes towards paying off the debt
• The Excel pmt, ppmt, cumprinc provide information
• Look at posted example, different times, and the happy and unhappy story
Formulas
• pmt computes fixed payment, same throughout the time period of loan
• ppmt computes amount towards principal • ipmt computes amount of interest. Note
this is the amount that is tax deductible.• cumprinc computes cumulative amount paid
towards principal• Use Excel function list or google help
Homework problems
• This was an exercise in exploring Excel.• The future value of an investment such as
retirement savings (FV)– Start off with $4000, add $2000 for 20 years
(question of when you start these payments)=FV(.04,20,2000,4000,0) yields $68,320.65
FV(.04,20,2000,4000,1) yields $70,702.90Note: given as negative total.Why is it more than 4000 + 20 * 2000 ($44,000) ???
Alternative approach for retirement: same results
• Start off with $4000, add $2000 for 20 years (question of when you start these payments)
• Compute value after each year• Adding at end of year:
4000 =A2*(1.04)+2000 …,,,,…. last entry is =T2*(1.04)+2000
• Adding at start of year, start off with 6000, terms are the same, except last entry is =T3*(1.04)
TV purchase• Purchasing decision: pay a lot now or stretch out
payments (PV). Issue (again) is when payments start.• Rate is for saving your money (it is very high)
= PV(.1,4,750,0,0) first 0 indicates complete payment, second indicates paying at end of period $2,377.40=PV(.1,4,750,0,1) pay at start $2615.14
So, if payments don’t start for a year and you will put the money to work now, the 4 payment method is cheaper.
Relative Addressing
• default – what we have done:– When a formula is copied from one column to
another • =C3*C18 from column C to column D, it becomes
=D3*D18• =B2-C5 from column C to column D, it becomes =C2-D5• Similarly for rows
• Recall that this is what we wanted in cookies, diet & exercise, mortgages
Absolute Addressing
• When you want addresses to stay the same, use $ before letter or number or both– = $C$2*C15 copied from column C to column D
becomes=$C$2*D15
• This has a role to play and you will see it. • I have not used it because I have
demonstrated ????
Naming
• Names of cells or ranges are absolute.• Used names in
– Midterm for ranges for frequency– Diet and exercise– Mortgage
But ….
• If the spreadsheet has values for which you want one dimension to be copied relatively and one not, naming will not work
• =A$2*A5 if copied from A3 to B3 will become=B$2*B5 and if copied to B4 will become=B$2*B6
Recall cookie lab
Change to columns corresponding to daysEach day, eat different cookiesCalculate costs, caloriesAt start of each day, have calorie goal and for each
cookie type, compute proportion of that day’s calories.
NEED: reference to row with calorie goals to be absolute, but can make column reference relative.
Advice
IF AND WHEN you need this type of thing, just remember that naming and absolute addressing are possibilities and work it out!
Do check after copy and paste operations.
VERY GENERAL ADVICE: many computer tools have default settings. Relative addressing is the default. Need to check that that is what you want.
Colbert Bump
• Several years ago, Stephen Colbert claimed that being on a show gave candidates (and others) a distinct bump.
• How to test this?
Colbert bump study by James Fowler
• http://jhfowler.ucsd.edu/colbert_bump.pdf
Presidential Elections
• What is (was) a swing state / battleground state?
• History: shows roles of different states: http://www.nytimes.com/interactive/2012/10/15/us/politics/swing-history.html
Previous election
• Note: I emailed them and they are working on similar map for 2012. This is a big effort.
• Stanford Spatial map of precincts • http://faculty.purchase.edu/jeanine.meyer/pr
ecincts2008.html
Visualizations: 2012 election results
http://2012electoralcollegecalculator.com/blog/u-s-presidential-election-result-2012-11-09/
More maps
• http://www.dailykos.com/story/2012/07/10/1106266/-Electoral-College-Map-Porn-Cartogram-Peep-Show
Comments on visualizations?
• Which were appealing / informative / ?
• Did the fact that NY probably will NOT be a swing state in 2016 make you less interested in voting?
Electoral college
Not this election but ….What is the electoral college?
To put it another way, how do we elect the president?
Answer• Each state has a number of electoral college votes
equal to the number of senators (2) plus the number of representatives.• So it is roughly proportional to population, but not quite.
Small states get somewhat more.• Washington, DC has 3 votes• All but 2 states have winner-take-all.• Maine and Nebraska have some winner take all and
some by Congressional District.• 538 votes
What do you think?
• Is the electoral college a good thing? What is the alternative?
• Is it the reason that most of the action is only in the swing states?– “Candidates running to be president of Ohio.” Not
quite true.
Why?
• Do I / we spend time on elections?
Reasons• Lots of mathematics
• Lots of quantitative reasoning• Lots of visualizations
• Way to promote civic engagement
• It is a topic I am interested in…• [Not original with me, but I can’t find the source] Don’t
limit yourself to things (e.g., courses) that you are interested in. Do things to make yourself more interesting.
CartogramsPopulation:
https://search.yahoo.com/yhs/search?p=cartogram+states+population&ei=UTF-8&hspart=mozilla&hsimp=yhs-002
Electoral votes: https://search.yahoo.com/yhs/search?
p=cartogram&ei=UTF-8&hspart=mozilla&hsimp=yhs-002
https://en.wikipedia.org/wiki/Electoral_College_%28United_States%29
Visualizations
• http://ilovecharts.tumblr.com/• http://www.theatlantic.com/business/
archive/2012/04/how-we-pay-taxes-11-charts/255954/
• Diagrams that changed the world: http://www.brainpickings.org/index.php/2012/12/21/100-diagrams-that-changed-the-world/
More
Collection: http://chartsbin.com/graph?sortby=chart_modified_date
Sports
• Old World Series championships: http://www.statcrunch.com/5.0/viewreport.php?reportid=7108
• World Cup: http://www.tableausoftware.com/public/gallery/history-world-cup
Visualizations, cont.
• Recommendation: look up work of Edmund Tufte • Need to work.
• Books, posters, talks
Space shuttle Challenger• Background:
• 0-rings used for rocket booster • Political pressure to make equipment around the country• Pressure to have flight with teacher aboard
• critical decision made to go ahead with flight even though weather was predicted to be cold
• Tufte claims that the presentation was (prime) cause of wrong decision being made.
• For more discussion: see http://www.onlineethics.org/cms/12709.aspx
Diagram shown
Diagram shown
Note
Information on temperature versus tile damage was known but the so-called crayons in a box showed flights in chronological order not sorted by damage or temperature or …
Certain engineers did argue against the flight but decision made to go ahead.
Substitute diagram
Presentations• Get your proposal in
– You cannot present (earn zero points) if no proposal
• At presentation, bring in “1-pager”– Abstract 100 to 200 words. Formal English
describing presentation– Works cited: proper format (this means more than
just web address: author, organization, title, date posted AND date viewed)
– Most important diagram, chart or picture
Successful presentation
• Be prepared• Be interested in topic
– If you aren’t, we won’t be• Keep audience in mind and • … get audience involved
– make us work….
Quantitative aspects
• Definitions• What’s the difference?
– Context, comparisons, categories• (As appropriate): denominators, distribution,
data source, dimension• Do make comparisons.
• Trends over time• Do consider counter-arguments.
Homework
• Proposals• Presentations• Postings