# Data Frames and Tibbles — R Programming

Source: https://www.geekswithgeeks.com/en/r-programming/d-frames

> Create, inspect and subset data frames and tibbles.

## Tables of data

A **data frame** is R's central structure for tabular data: a list of **equal-length columns**, each column a vector of one type, with rows representing observations. Create one with `data.frame()` or read it from a file. Inspect with `head()`, `tail()`, `nrow()`, `ncol()`, `dim()`, `names()`, `str()`, `summary()` and, in the tidyverse, `glimpse()`. Access a column with `df$column` or `df[["column"]]`, and subset rows and columns with `df[rows, cols]`, for example `df[df$total > 500, c("id", "city")]`. A **tibble** is the tidyverse's modern data frame: it prints more helpfully (types shown, only the first rows), never converts strings to factors, never partially matches column names, and complains loudly about mistakes. Most tidyverse functions return tibbles, and they work anywhere a data frame is expected. Large datasets can also use **data.table** (very fast) or the Arrow and DuckDB integrations for data larger than memory.

## Creating and exploring a tibble

Base R subsetting and tidyverse inspection side by side.

```r
library(tibble)
library(dplyr)

orders <- tibble(
  id = c("o1", "o2", "o3", "o4"),
  city = c("Pune", "Delhi", "Pune", "Mumbai"),
  total = c(1200, 300, 800, 2500),
  paid = c(TRUE, FALSE, TRUE, TRUE)
)

glimpse(orders)                         # column types and first values
summary(orders$total)
nrow(orders)                            # 4

orders$total * 1.18                      # a column is just a vector
orders[orders$total > 500, c("id", "city")]   # base R subsetting
mean(orders$total[orders$paid])          # average of paid orders: 1500

orders$size <- ifelse(orders$total > 1000, "large", "small")   # add a column
```

## Prefer tibbles for new code

Base data frames silently allow `df$tot` to match a column named `total` (partial matching). Tibbles refuse and return NULL with a warning, catching typos early.

**Quiz:** What is a data frame in R?

- [x] A list of equal-length column vectors forming a table
- [ ] A matrix of characters
- [ ] A plot type
- [ ] A package

*Answer:* A list of equal-length column vectors forming a table. Each column is a vector, and all columns have the same length.