Useful packages: R: library(matrixcalc) Python: numpy Matrix generation: R: matrix(1:6, 2, 3) Python: np.arange(1,7).reshape(2,3) construct a diagnal matrix: R: advanced-R diag(vector, nrow, ncol) #construct a matrix which diagonal elements is equal to the vector diag(matrix) # a vector which elements is…
I found the easiest way to install R extention for Ubuntun RapidMiner -> Marketplace -> R Extention RStudio -> Tools -> Install Packages… -> Input in the field “Packages”: rJava, JavaGD Or input in R Console: install.packages(c(“rJava”,”JavaGD”)) Restart RapidMiner you get a popup…
Useful web sites for R: Quick-R R-bloggers r-tutor Kickstarting R cran.r-project.org r books Andrew Field, youtube videos Simply Statistics idre stat programiz shiny learn graph library: lattice, ggvis, ggplot2 About Package install.packages(“ggplot2”), you can also install with RStudio menu: Tools…
I work on several computers, sometimes Widows, sometimes Linux, so I got a problem after I pull my project file from Git. That is the file path. To cope with this problem, I have to find out which computer I…
If you want to read an image, you will need the ‘image’ package: import Image read the image: Image.open(filename) convert the Image to grey scale: Image.open(filename).convert(‘L’) convert the image to array: numpy.asarray(Image.open(filename).convert(‘L’)) Notice: Here is a introduction to “Image” package…
I have a list and I want to get the rank for each member. This is important for many data mining algorithm, for example kNN (k-Nearest-Neighbor), you want to know the rank of a certain record. For example: myList =…
There are many ways to sort a 2d arrays. In general, you can use the sorted(), np.array.sort(),… But you should also understand what is meaning of list1.sort(list2) ravel() vs. flatten() what return the key function back in sorted() what will…
