Articles by Jesse John

R Howtos

1. How to Check for Missing Values Using a Boolean Operator in R
2. How to Locate R Script and Data Files Without Changing the Working Directory
3. How to Size Plots in Beamer Slides Made Using R Markdown
4. How to Identify R Object Properties
5. How to Create a Ggplot2 Visualization With a Transparent Background
6. How to Include a Local Image File in an R Presentation
7. How to Use the Predict Function on a Linear Regression Model in R
8. $ Operator Is Invalid for Atomic Vectors Error in R
9. How to Create a Random Matrix With Constant Row Sums in R
10. How to Restart R in RStudio
11. How to Filter a Data Frame With Multiple Conditions in R
12. How to Paste Strings Without Spaces in R
13. How to Use the %*% Operator in R
14. How to Create a 3D Surface Plot From (x,y,z) Coordinates
15. How to Create a 3D Perspective Plot in R
16. How to Test Hypothesis in R
17. How to Create Combinations and Permutations of Vectors in R
18. How to Use Cross-Validation for a KNN Classification Model in R
19. How to Create and Interpret Dummy Variables in R
20. How to Test for Normality of Data in R
21. How to Create and Visualize a Correlation Matrix in R
22. How to Perform Time Series Analysis and Forecasts in R
23. How to Perform K-Means Clustering in Base R
24. How to Use the group_by Function in R Dplyr
25. How to Compute Binomial Coefficients in Java
26. How to Use the if and if...else Statements in R
27. How to Customize the PCA Biplot in R
28. How to Use the Source Function to Run Another R Script
29. How to Interpret Output of system.time Function in R
30. How to Convert Multiple Columns From Integer to Numeric Type in R
31. How to Generate a Regular Sequence of Numbers in R
32. How to Set Location of Current File as Working Directory in R Studio
33. How to Add a Calculated Column to a Matrix in R
34. How to Remove Object Names and Dimnames in R
35. How to Find the Null Space of a Matrix in R
36. How to Uninstall R and All Its Packages on Windows
37. How to Remove User-Defined Objects From the Workspace in R
38. Color-Blind Accessible Colors in Base R
39. How to Pass Command Line Arguments to R CMD BATCH and Rscript
40. How to Read a Text File Line by Line in R
41. How to Use Vectorized if Function With Multiple Conditions in R
42. How to Sum Selected Columns of an R Data Frame
43. How to Install R Packages From Source
44. How to Break a for Loop in R
45. How to Drop Multiple Columns From a Data Frame Using Dplyr
46. How to Stop Running R Code With the Keyboard or Mouse
47. How to Export a Data Frame From R to Microsoft Excel
48. How to Calculate the R-Squared Statistic in R
49. How to Remove the First Character From a String in R

Python How-To's

1. How to Get Max Heap in Python
2. How to Differentiate Iterator and Generator in Python
3. How to Read a Text File and Print Its Contents in Python
4. How to Print a Multiplication Table in Python Using Basic Programming Concepts
5. Use and in Python