1 / 44

Weighted kNN , clustering, more plottong , Bayes

Weighted kNN , clustering, more plottong , Bayes. Peter Fox Data Analytics – ITWS-4963/ITWS-6965 Week 6 b , February 28, 2014. Plot tools/ tips. http ://statmethods.net/advgraphs/ layout.html http://flowingdata.com/2014/02/27/how-to-read-histograms-and-use-them-in-r /

sofia
Télécharger la présentation

Weighted kNN , clustering, more plottong , Bayes

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. Weighted kNN, clustering, more plottong, Bayes Peter Fox Data Analytics – ITWS-4963/ITWS-6965 Week 6b, February 28, 2014

  2. Plot tools/ tips http://statmethods.net/advgraphs/layout.html http://flowingdata.com/2014/02/27/how-to-read-histograms-and-use-them-in-r/ pairs, gpairs, scatterplot.matrix, clustergram, etc. data() # precip, presidents, iris, swiss, sunspot.month (!), environmental, ethanol, ionosphere More script fragments in Lab6b_*_2014.R on the web site (escience.rpi.edu/data/DA )

  3. Weighted KNN? require(kknn) data(iris) m <- dim(iris)[1] val <- sample(1:m, size = round(m/3), replace = FALSE, prob = rep(1/m, m)) iris.learn <- iris[-val,] iris.valid <- iris[val,] iris.kknn <- kknn(Species~., iris.learn, iris.valid, distance = 1, kernel = "triangular") summary(iris.kknn) fit <- fitted(iris.kknn) table(iris.valid$Species, fit) pcol <- as.character(as.numeric(iris.valid$Species)) pairs(iris.valid[1:4], pch = pcol, col = c("green3", "red”)[(iris.valid$Species != fit)+1])

  4. Try Lab6b_8_2014.R

  5. New dataset - ionosphere require(kknn) data(ionosphere) ionosphere.learn <- ionosphere[1:200,] ionosphere.valid <- ionosphere[-c(1:200),] fit.kknn <- kknn(class ~ ., ionosphere.learn, ionosphere.valid) table(ionosphere.valid$class, fit.kknn$fit) # vary kernel (fit.train1 <- train.kknn(class ~ ., ionosphere.learn, kmax = 15, kernel = c("triangular", "rectangular", "epanechnikov", "optimal"), distance = 1)) table(predict(fit.train1, ionosphere.valid), ionosphere.valid$class) #alter distance (fit.train2 <- train.kknn(class ~ ., ionosphere.learn, kmax = 15, kernel = c("triangular", "rectangular", "epanechnikov", "optimal"), distance = 2)) table(predict(fit.train2, ionosphere.valid), ionosphere.valid$class)

  6. Cluster plotting source("http://www.r-statistics.com/wp-content/uploads/2012/01/source_https.r.txt") # source code from github require(RCurl) require(colorspace) source_https("https://raw.github.com/talgalili/R-code-snippets/master/clustergram.r") data(iris) set.seed(250) par(cex.lab = 1.5, cex.main = 1.2) Data <- scale(iris[,-5]) # scaling clustergram(Data, k.range = 2:8, line.width = 0.004) # line.width - adjust according to Y-scale

  7. Clustergram

  8. Any good? set.seed(500) Data2 <- scale(iris[,-5]) par(cex.lab = 1.2, cex.main = .7) par(mfrow = c(3,2)) for(i in 1:6) clustergram(Data2, k.range = 2:8 , line.width = .004, add.center.points = T)

  9. How can you tell it is good? set.seed(250) Data <- rbind( cbind(rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3)), cbind(rnorm(100,1, sd = 0.3),rnorm(100,1, sd = 0.3),rnorm(100,1, sd = 0.3)), cbind(rnorm(100,2, sd = 0.3),rnorm(100,2, sd = 0.3),rnorm(100,2, sd = 0.3))) clustergram(Data, k.range = 2:5 , line.width = .004, add.center.points = T)

  10. More complex… set.seed(250) Data <- rbind( cbind(rnorm(100,1, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3)), cbind(rnorm(100,0, sd = 0.3),rnorm(100,1, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3)), cbind(rnorm(100,0, sd = 0.3),rnorm(100,1, sd = 0.3),rnorm(100,1, sd = 0.3),rnorm(100,0, sd = 0.3)), cbind(rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,0, sd = 0.3),rnorm(100,1, sd = 0.3))) clustergram(Data, k.range = 2:8 , line.width = .004, add.center.points = T)

  11. Look at the location of the cluster points on the Y axis. See when they remain stable, when they start flying around, and what happens to them in higher number of clusters (do they re-group together) • Observe the strands of the datapoints. Even if the clusters centers are not ordered, the lines for each item might (needs more research and thinking) tend to move together – hinting at the real number of clusters • Run the plot multiple times to observe the stability of the cluster formation (and location) http://www.r-statistics.com/2010/06/clustergram-visualization-and-diagnostics-for-cluster-analysis-r-code/

  12. Swiss - pairs pairs(~ Fertility + Education + Catholic, data = swiss, subset = Education < 20, main = "Swiss data, Education < 20")

  13. ctree require(party) swiss_ctree<- ctree(Fertility ~ Agriculture + Education + Catholic, data = swiss) plot(swiss_ctree)

  14. Hierarchical clustering > dswiss<- dist(as.matrix(swiss)) > hs<- hclust(dswiss) > plot(hs)

  15. scatterplotMatrix

  16. require(lattice); splom(swiss)

  17. Decision tree (reminder) > str(iris) 'data.frame': 150 obs. of 5 variables: $ Sepal.Length: num 5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ... $ Sepal.Width : num 3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ... $ Petal.Length: num 1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ... $ Petal.Width : num 0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ... $ Species : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ... > str(swiss) …

  18. Beyond plot: pairs pairs(iris[1:4], main = "Anderson's Iris Data -- 3 species”, pch= 21, bg = c("red", "green3", "blue")[unclass(iris$Species)]) Try Lab6b_2_2014.R - USJudgeRatings

  19. Try hclust for iris

  20. gpairs(iris) Try Lab6b_3_2014.R

  21. Better scatterplots install.packages("car") require(car) scatterplotMatrix(iris) Try Lab6b_4_2014.R

  22. splom(iris) # default Try Lab6b_7_2014.R

  23. splom extra! require(lattice) super.sym<- trellis.par.get("superpose.symbol") splom(~iris[1:4], groups = Species, data = iris, panel = panel.superpose, key = list(title = "Three Varieties of Iris", columns = 3, points = list(pch = super.sym$pch[1:3], col = super.sym$col[1:3]), text = list(c("Setosa", "Versicolor", "Virginica")))) splom(~iris[1:3]|Species, data = iris, layout=c(2,2), pscales = 0, varnames = c("Sepal\nLength", "Sepal\nWidth", "Petal\nLength"), page = function(...) { ltext(x = seq(.6, .8, length.out = 4), y = seq(.9, .6, length.out = 4), labels = c("Three", "Varieties", "of", "Iris"), cex = 2) }) parallelplot(~iris[1:4] | Species, iris) parallelplot(~iris[1:4], iris, groups = Species, horizontal.axis = FALSE, scales = list(x = list(rot = 90))) > Lab6b_7_2014.R

  24. Ctree > iris_ctree<- ctree(Species ~ Sepal.Length + Sepal.Width + Petal.Length + Petal.Width, data=iris) > print(iris_ctree) Conditional inference tree with 4 terminal nodes Response: Species Inputs: Sepal.Length, Sepal.Width, Petal.Length, Petal.Width Number of observations: 150 1) Petal.Length <= 1.9; criterion = 1, statistic = 140.264 2)* weights = 50 1) Petal.Length > 1.9 3) Petal.Width <= 1.7; criterion = 1, statistic = 67.894 4) Petal.Length <= 4.8; criterion = 0.999, statistic = 13.865 5)* weights = 46 4) Petal.Length > 4.8 6)* weights = 8 3) Petal.Width > 1.7 7)* weights = 46

  25. plot(iris_ctree) Try Lab6b_5_2014.R > plot(iris_ctree, type="simple”) # try this

  26. Try these on mapmeans, etc.

  27. Something simpler – kmeans and… > mapmeans<-data.frame(as.numeric(mapcoord$NEIGHBORHOOD), adduse$GROSS.SQUARE.FEET, adduse$SALE.PRICE, adduse$'querylist$latitude', adduse$'querylist$longitude') > mapobjnew<-kmeans(mapmeans,5, iter.max=10, nstart=5, algorithm = c("Hartigan-Wong", "Lloyd", "Forgy", "MacQueen")) > fitted(mapobjnew,method=c("centers","classes")) • Others?

  28. Plotting clusters (DIY) library(cluster) clusplot(mapmeans, mapobj$cluster, color=TRUE, shade=TRUE, labels=2, lines=0) # Centroid Plot against 1st 2 discriminant functions #library(fpc) plotcluster(mapmeans, mapobj$cluster) • dendogram? library(fpc) • cluster.stats

  29. Bayes > cl <- kmeans(iris[,1:4], 3) > table(cl$cluster, iris[,5]) setosaversicolorvirginica 2 0 2 36 1 0 48 14 3 50 0 0 # > m <- naiveBayes(iris[,1:4], iris[,5]) > table(predict(m, iris[,1:4]), iris[,5]) setosaversicolorvirginica setosa 50 0 0 versicolor 0 47 3 virginica 0 3 47 pairs(iris[1:4],main="Iris Data (red=setosa,green=versicolor,blue=virginica)", pch=21, bg=c("red","green3","blue")[unclass(iris$Species)])

  30. Digging into iris classifier<-naiveBayes(iris[,1:4], iris[,5]) table(predict(classifier, iris[,-5]), iris[,5], dnn=list('predicted','actual')) classifier$apriori classifier$tables$Petal.Length plot(function(x) dnorm(x, 1.462, 0.1736640), 0, 8, col="red", main="Petal length distribution for the 3 different species") curve(dnorm(x, 4.260, 0.4699110), add=TRUE, col="blue") curve(dnorm(x, 5.552, 0.5518947 ), add=TRUE, col = "green")

  31. Using a contingency table > data(Titanic) > mdl <- naiveBayes(Survived ~ ., data = Titanic) > mdl Naive Bayes Classifier for Discrete Predictors Call: naiveBayes.formula(formula = Survived ~ ., data = Titanic) A-priori probabilities: Survived No Yes 0.676965 0.323035 Conditional probabilities: Class Survived 1st 2nd 3rd Crew No 0.08187919 0.11208054 0.35436242 0.45167785 Yes 0.28551336 0.16596343 0.25035162 0.29817159 Sex Survived Male Female No 0.91543624 0.08456376 Yes 0.51617440 0.48382560 Age Survived Child Adult No 0.03489933 0.96510067 Yes 0.08016878 0.91983122 Try Lab6b_9_2014.R

  32. http://www.ugrad.stat.ubc.ca/R/library/mlbench/html/HouseVotes84.htmlhttp://www.ugrad.stat.ubc.ca/R/library/mlbench/html/HouseVotes84.html require(mlbench) data(HouseVotes84) model <- naiveBayes(Class ~ ., data = HouseVotes84) predict(model, HouseVotes84[1:10,-1]) predict(model, HouseVotes84[1:10,-1], type = "raw") pred <- predict(model, HouseVotes84[,-1]) table(pred, HouseVotes84$Class)

  33. Exercise for you > data(HairEyeColor) > mosaicplot(HairEyeColor) > margin.table(HairEyeColor,3) Sex Male Female 279 313 > margin.table(HairEyeColor,c(1,3)) Sex Hair Male Female Black 56 52 Brown 143 143 Red 34 37 Blond 46 81 How would you construct a naïve Bayes classifier and test it?

  34. Assignment 5 • Project proposals… • Let’s look at it • Assignment 4 - how is it going – assume you all start after today?

  35. Assignment 6 preview • Your term projects should fall within the scope of a data analytics problem of the type you have worked with in class/ labs, or know of yourself – the bigger the data the better. This means that the work must go beyond just making lots of figures. You should develop the project to indicate you are thinking of and exploring the relationships and distributions within your data. Start with a hypothesis, think of a way to model and use the hypothesis, find or collect the necessary data, and do both preliminary analysis, detailed modeling and summary (interpretation). • Note: You do not have to come up with a positive result, i.e. disproving the hypothesis is just as good. Please use the section numbering below for your written submission for this assignment. • Introduction (2%) • Data Description (3%) • Analysis (8%) • Model Development (8%) • Conclusions and Discussion (4%) • Oral presentation (5%) (10 mins)

  36. Assignments to come • Term project (6). Due ~ week 13/ 14 – early May. 30% (25% written, 5% oral; individual). Available after spring break. • Assignment 7: Predictive and Prescriptive Analytics. Due ~ week 10. 15% (15% written; individual);

  37. Admin info (keep/ print this slide) • Class: ITWS-4963/ITWS 6965 • Hours: 12:00pm-1:50pm Tuesday/ Friday • Location: SAGE 3101 • Instructor: Peter Fox • Instructor contact: pfox@cs.rpi.edu, 518.276.4862 (do not leave a msg) • Contact hours: Monday** 3:00-4:00pm (or by email appt) • Contact location: Winslow 2120 (sometimes Lally 207A announced by email) • TA: Lakshmi Chenicheri chenil@rpi.edu • Web site: http://tw.rpi.edu/web/courses/DataAnalytics/2014 • Schedule, lectures, syllabus, reading, assignments, etc.

More Related