Hey there! Let's work through this ECDF issue step by step—this is a super common gotcha for R newbies, so don't worry, we'll get it sorted.

First, let's break down the clue you gave: when you run MyData[1], it outputs all your 100k values. That tells me your MyData object is probably a data frame (the default structure when you import CSV files with read.csv() or read_csv()). The problem here is that MyData[1] returns the first column as a data frame subset—not a plain numeric vector, which is what the ecdf() function needs to work properly.

Here's how to fix it: #

• Confirm your data structure first
  Run this command to check what type of object MyData is:

  str(MyData)
  

  You'll probably see something like 'data.frame': 100000 obs. of 1 variable:, which confirms it's a single-column data frame.

• Extract the numeric vector correctly
  Instead of MyData[1], use one of these two syntaxes to pull out the column as a vector:

  • Double brackets: MyData[[1]] (this works regardless of the column name)
  • Comma indexing: MyData[, 1] (the comma tells R you want all rows from the first column)

• Run ECDF with the vector
  Now assign the vector to a variable and pass it to ecdf():

  # Extract the numeric vector
  numeric_values <- MyData[[1]]
  # Create the ECDF object
  P <- ecdf(numeric_values)
  

  This should work without errors!

Quick sanity check: #

If you're still getting errors, make sure your column is actually numeric. Run:

class(numeric_values)

If it returns "character" instead of "numeric", you'll need to convert it first:

numeric_values <- as.numeric(MyData[[1]])

This can happen if your CSV had non-numeric values hiding somewhere (like a header row that didn't import correctly, or stray text in the column).

Example to test with: #

If you want to replicate this fix with dummy data, try:

# Make a fake 100k-row data frame
MyData <- data.frame(my_values = rnorm(100000))
# Wrong way (will throw an error)
P_wrong <- ecdf(MyData[1])
# Right way
P_right <- ecdf(MyData[[1]])
# Test the ECDF
P_right(0) # Should return the proportion of values <= 0

Hope that clears things up—you were so close, just a tiny syntax tweak was needed!

内容的提问来源于stack exchange，提问作者A.A