Gopalakrishna Palem

6 Questions 63 Answers 0 Followers

Questions related from Gopalakrishna Palem

What is the best method for Time-series prediction accounting external influences?

Any practical (e.g. easily implementable in R) methods for predicting the values for a given time series that account for additional/external variables influence ? For example, the no. of orders...

09 September 2014 2,674 4 View

What is the suggested method to predict the effect of price change on sales when the price-change is happening for the first time?

Price-elasticity models do not fit here (since they need previous/historic data with price changes to 'learn' the effect). We have sales-data for different items (with no price-changes till now)....

04 April 2014 8,034 1 View

How can I programmatically enumerate columns of given type from a given data frame in R?

Given a data frame, how do I programmatically list only columns of a certain type (say, only 'factor', 'numeric', etc.)? I created a function that receives data frames. I now need to do certain...

03 March 2014 1,343 3 View

How do you set a new column name in cbind() inline in R to be a variable name supplied?

The below version does not work. It just names the column as 'colName' and not 'weekDay'. addWeekDay

03 March 2014 3,270 7 View

How do you specify custom return value for Max, Min in R for empty input (instead of the default +Inf and -Inf)?

In R, I am using Min and Max to find minimum and maximum values for a given vector. This vector is a result of computation and filter and often times could be NULL or empty list. In such case,...

09 September 2013 5,087 3 View

What is the best method to measure consistency?

Here is the situation: We have multiple students and different subjects. The goal is to find the "consistent performer" ranking for the students based on their whole year performance in...

07 July 2013 6,537 5 View