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About Jesse John

Jesse is passionate about data analysis and visualization. He uses the R statistical programming language for all aspects of his work.

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