I. Data Import and Manipulation:

1. Read CSV:

data <- read.csv("file.csv")

2. Read Excel:

library(readxl); data <- read_excel("file.xlsx")

3. Subset Data:

subset_data <- data[data$condition == "A", ]

4. Select Columns:

selected_cols <- data[, c("col1", "col2")]

5. Filter Rows:

filtered_data <- data[data$age > 18, ]

6. Group by and Summarize:

library(dplyr); summarised_data <- data %>% group_by(category) %>% summarise(mean_value = mean(value))

7. Merge Data:

merged_data <- merge(data1, data2, by = "common_column")

8. Convert to Date:

data$date <- as.Date(data$date_string, format="%Y-%m-%d")

9. Pivot Data:

library(tidyr); 
pivoted_data <- spread(data, key = "key_col", value = "value_col")

10. Reshape Data:

library(reshape2); 
melted_data <…