How do I delete rows in a data frame?
I have a data frame named “mydata” that looks like this this: I’d like to delete row 2,4,6. For example, like this:
R
Error in Confusion Matrix : the data and reference factors must have the same number of levels
I’ve trained a Linear Regression model with R caret. I’m now trying to generate a confusion matrix and keep getting the following error: Error in confusionMatrix.default(pred, testing$Final) : the data and reference factors must have the same number of levels The error occurs when generating the confusion matrix. The levels are the same on both … Read more
Difference between paste() and paste0()
As explained in this blog by Tyler Rinker: paste has 3 arguments. paste (…, sep = ” “, collapse = NULL) The … is the stuff you want to paste together and sep and collapse are the guys to get it done. There are three basic things I paste together: A bunch of individual character strings. 2 or more strings … Read more
R issue “object not found”
Here’s my guess at what might work the way you wanted: You should realize that the rest of my_data will have evaporated and be garbage collected after return from the elbow call. I could have showed you how to use your original expression following attach(), which would have been arguably safe within that function, but that would have … Read more
What are the “standard unambiguous date” formats for string-to-date conversion in R?
This is documented behavior. From ?as.Date: format: A character string. If not specified, it will try ‘”%Y-%m-%d”‘ then ‘”%Y/%m/%d”‘ on the first non-‘NA’ element, and give an error if neither works. as.Date(“01 Jan 2000”) yields an error because the format isn’t one of the two listed above. as.Date(“01/01/2000”) yields an incorrect answer because the date … Read more
‘x’ and ‘y’ lengths differ ERROR when plotting
From the code you provided, Vehic_vol is not a column of VehicleData. If you enter in it returns Note that NULL and VehicleData$CITY_MPG have different lengths (use length() to verify that). Try this instead or
mean() warning: argument is not numeric or logical: returning NA
From R 3.0.0 onwards mean(<data.frame>) is defunct (and passing a data.frame to mean will give the error you state) A data frame is a list of variables of the same number of rows with unique row names, given class “data.frame”. In your case, result has two variables (if your description is correct) . You could … Read more
Non-numeric Argument to Binary Operator Error in R
Because your question is phrased regarding your error message and not whatever your function is trying to accomplish, I will address the error. – is the ‘binary operator’ your error is referencing, and either CurrentDay or MA (or both) are non-numeric. A binary operation is a calculation that takes two values (operands) and produces another value (see wikipedia for more). + is … Read more
What does “Error: object ‘‘ not found” mean?
I got the error message: Error: object ‘x’ not found Or a more complex version like Error in mean(x) : error in evaluating the argument ‘x’ in selecting a method for function ‘mean’: Error: object ‘x’ not found What does this mean?
What are the “standard unambiguous date” formats for string-to-date conversion in R?
This is documented behavior. From ?as.Date: format: A character string. If not specified, it will try ‘”%Y-%m-%d”‘ then ‘”%Y/%m/%d”‘ on the first non-‘NA’ element, and give an error if neither works. as.Date(“01 Jan 2000”) yields an error because the format isn’t one of the two listed above. as.Date(“01/01/2000”) yields an incorrect answer because the date … Read more