Problem with Ubuntu-mate Error “Temporary Failure resolving “ports.ubuntu.com’

I have a Raspberry Pi 3 Model B. I have downloaded and installed ubuntu-mate-18.04.2-beta1-desktop-armhf+raspi-ext4.img. When I try to sudo apt-get update I get the error Temporary Failure resolving ‘ports.ubuntu.com’ The raspberry pi has an ethernet connection to the internet. I have searched many times to find a solution but nothing seems to work. Is this…

Details

How can I iterate a function over specific columns of a series of dataframes where I can set the order?

I work for an insurance company and I am trying to improve something that I built. I have about 150 data frames that look like this: library(data.table) dt_Premium<-data.table(Policy = c(“Pol123″,”Pol333″,”Pol555″,”Pol999”), Base_Premium_Fire= c(45,55,105,92), Base_Premium_Water= c(20,21,24,29), Base_Premium_Theft= c(3,5,6,7)) dt_Discount_Factors<-data.table(Policy = c(“Pol123″,”Pol333″,”Pol555″,”Pol999”), Discount_Factor_Fire= c(.9,.95,.99,.97), Discount_Factor_Water= c(.8,.85,.9,.96), Discount_Factor_Theft= c(1,1,1,1)) dt_Territory_Factors<-data.table(Policy = c(“Pol123″,”Pol333″,”Pol555″,”Pol999”), Territory_Factor_Fire= c(1.9,1.2,.91,1.03), Territory_Factor_Water= c(1.03,1.3,1.25,1.01), Territory_Factor_Theft= c(1,1.5,1,.5)) dt_Fixed_Expense<-data.table(Policy…

Details