1 / 26

Statistick á analýza dat

Statistick á analýza dat. Daniel Svozil Laboratoř informatiky a chemie, FCHT Vojtěch Spiwok, ÚBM, FPBT. Informace. přednášky – základy, opáčko, cvičení – R http ://ich.vscht.cz/~ svozil/teaching.html Další literatura D. J. Rumsey, Statistics for Dummies, 2011

gabriel-cardenas
Download Presentation

Statistick á analýza dat

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. Statistická analýza dat Daniel Svozil Laboratoř informatiky a chemie, FCHT Vojtěch Spiwok, ÚBM, FPBT

  2. Informace • přednášky – základy, opáčko, cvičení – R • http://ich.vscht.cz/~svozil/teaching.html • Další literatura • D. J. Rumsey, Statistics for Dummies, 2011 • D. J. Rumsey, Intermediate Statistics for Dummies, 2007 • zápočet, zkouška – bude oznámeno

  3. Valuing houses How much money should you expect to pay for 1 300 ft2 house? 104 000 $ Same question now with 1 800 ft2 ? 144 000 $

  4. Valuing houses How much money should you expect to pay for 2 100 ft2 house? 168 000 $ 21 is just a half between 18 and 24.

  5. What a statistician does? • Look at data • Program computers • Run statistics software • Drink beer

  6. Linear relationship Is there a fixed amount per square foot? No What if I change 1 400 to 1 300? What is the answer now? Yes

  7. Scatter plots (bodový graf) • Please, take a pen and a paper and draw a scatter plot of these data. PRICE SIZE

  8. Scatter plots Is there a fixed price per square foot? No

  9. Scatter plots What do you think, is the data linear? Let’s make a scatter plot. Surprisingly, the data is linear, even if there is no fixed price per square foot! PRICE = AA x SIZE + BB PRICE = 30 x SIZE + 2 000

  10. Scatter plots Draw scatterplot and tell me if these data are linear (i.e., do they lie in a line?). outliers

  11. Bar chart Warm up. Are these data linear? No How much to pay for a 2 200 ft2 house? Just simply interpolate. 105 000 Do you have trust in this number?

  12. Bar chart • Take your data and pull them together.

  13. Bar chart

  14. Bar chart • Much finer representation of the data • Bar chart allows you to understand global trends • Statistician uses cumulative tools (such as bar graph) to gain the understanding of the underlying data.

  15. Histograms • Special case of bar chart. • Bar chart looks at 2D data, histogram to 1D data. That is the main difference.

  16. Age distribution • Draw a histogram at the paper with the bins by 10 years (i.e. 0-10, 11-20, …) 29 27 14 21 12 9 17 14 32 39 3 9 4 33 38 29 21 31 8 15

  17. Věková pyramida věková pyramida (strom života) grafické znázornění věkové struktury obyvatelstva source: http://cs.wikipedia.org/wiki/V%C4%9Bkov%C3%A1_pyramida

  18. Histogram • Now I will collect heights of all of you in this room. • Use Interactive Histogram Applet: http://www.shodor.org/interactivate/activities/Histogram/ • interval, bin

  19. Histogram – Body fat • In Interactive Histogram Applet – choose „Body fat % in 252 men“ dataset. • Find reasonable bin size • Answer following questions. No matter of bin size what is always true? • Most scores fall around 20%. • The shape is roughly symmetrical. • Most scores fall in the middle of distribution. • There are more scores between 15 and 25 than between 35 and 50. • There are more scores between 0 and 10 than between 18 and 24. • Relatively more men have a body fat above 35% or below 5%.

  20. Histogram – Income distribution • United States Census Bureau – http://www.census.gov

  21. Histogram – Income distribution • This is an example of a (positively) skewed distribution (zprava zešikmené rozdělení). • This distribution is not symmetrical. • Most incomes fall to the left of the distribution.

  22. Pie charts • koláčový graf • elections • Party A – 50% • Party B – 50% • Party A – 724 000 votes • Party B – 181 000 votes

  23. A B C D E

  24. Pie charts • Party A – 175 000 • Party B – 50 000 • Party C – 25 000 • Party D – 50 000 • Please, draw the pie chart A: 4/12 B: 2/12 C: 1/12 D: 2/12

  25. Bar chart and scatter plot • Which scatter plot corresponds to this bar chart?

  26. Pie chart to histogram • Which histogram looks like it cames from the same data?

More Related