search for: coorrectly

deriv seems to have problems with a minus-sign before a bracket. Below are four examples of the same function, the top one is wrong, all others are correct (hopefully). Rest of expression not shown, it is the same for all versions. _ platform i386-pc-mingw32 arch x86 os Win32 system x86, Win32 status major 1 minor 3.0 year 2001 month 06 day 22 language R

List, I am trying to extract summary statistics from a data frame with several variables (and NAs) into a dataframe with the columns: Variablename (ie the colnames of original data), mean, stdev, max, min, Valid N, Missing Values. Extracting the statistics is straightforward using stack and aggregate. However, I haven''t succeeded in obtaining the number of Missing Values. I can extract