Fitting a density curve to a histogram in R

by

If I understand your question correctly, then you probably want a density estimate along with the histogram:

X <- c(rep(65, times=5), rep(25, times=5), rep(35, times=10), rep(45, times=4))
hist(X, prob=TRUE)            # prob=TRUE for probabilities not counts
lines(density(X))             # add a density estimate with defaults
lines(density(X, adjust=2), lty="dotted")   # add another "smoother" density

Edit a long while later:

Here is a slightly more dressed-up version:

X <- c(rep(65, times=5), rep(25, times=5), rep(35, times=10), rep(45, times=4))
hist(X, prob=TRUE, col="grey")# prob=TRUE for probabilities not counts
lines(density(X), col="blue", lwd=2) # add a density estimate with defaults
lines(density(X, adjust=2), lty="dotted", col="darkgreen", lwd=2)

along with the graph it produces:

enter image description here

More Related Contents:

  1. Collapse / concatenate / aggregate a column to a single comma separated string within each group
  2. Replacing NAs with latest non-NA value
  3. Filter data.frame rows by a logical condition
  4. Evaluate expression given as a string
  5. Pass a data.frame column name to a function
  6. What is the difference between require() and library()?
  7. How to sort a character vector where elements contain letters and numbers in R?
  8. Plot two graphs in same plot in R
  9. Add column which contains binned values of a numeric column
  10. Replace all 0 values to NA
  11. How to find common elements from multiple vectors?
  12. Generate multiple graphics from within an R function
  13. Scheduling R Script
  14. Calculate group mean, sum, or other summary stats. and assign column to original data
  15. Scatterplot with marginal histograms in ggplot2
  16. A comprehensive survey of the types of things in R; ‘mode’ and ‘class’ and ‘typeof’ are insufficient
  17. Changing date format in R
  18. How to perform natural (lexicographic) sorting in R? [duplicate]
  19. Test if characters are in a string
  20. What does %>% function mean in R?
  21. How to order data by value within ggplot facets
  22. How to filter a data frame
  23. What’s the biggest R-gotcha you’ve run across?
  24. Logical operators (AND, OR) with NA, TRUE and FALSE
  25. Create categorical variable in R based on range
  26. Apply several summary functions (sum, mean, etc.) on several variables by group in one call
  27. Order of operator precedence when using “:” (the colon)
  28. How to fit a smooth curve to my data in R?
  29. Use hist() function in R to get percentages as opposed to raw frequencies
  30. R: How to split a data frame into training, validation, and test sets?

Leave a Comment