# Sample original dataframe
set.seed(123)  # for reproducibility
df <- data.frame(
  Month = sample(1:12, 1000, replace = TRUE),
  Month_Day = sample(1:31, 1000, replace = TRUE),
  Dollars = runif(1000, min = 0, max = 100)
)
head(df)

# Convert Month to abbreviated month names
df$Month <- month.abb[df$Month]

# Summarize the data by Month, Month_Day, and Dollar amount
summarized_df <- aggregate(Dollars ~ Month + Month_Day, data = df, FUN = sum)

# Create an empty matrix to store the results
result_matrix <- matrix(0, nrow = 31, ncol = 13, dimnames = list(NULL, c("Day", month.abb)))

# Fill in the day column
result_matrix[, 1] <- 1:31

# Fill in the dollar amounts
for (i in 1:nrow(summarized_df)) {
  month_idx <- match(summarized_df[i, "Month"], month.abb)
  day_idx <- as.integer(summarized_df[i, "Month_Day"])
  result_matrix[day_idx, month_idx + 1] <- summarized_df[i, "Dollars"]
}

# Convert the matrix to a dataframe
wide_df <- as.data.frame(result_matrix)

# Print the resulting dataframe
print(wide_df)