[R] Question on Bias calculations and question on read.fwf

Vadlamani, Satish {FLNA} SATISH.VADLAMANI at fritolay.com
Wed Oct 28 16:03:22 CET 2009


Hi All:
Bear with me on this longer e-mail.

Questions:
1) Can you share with me on any example code that you may have that calculates bias of a statistical forecast in a time series?

2) Supposed I have the file in the fixed width format (details below).
1-62 character key
63-76 sales data point 1
77-90 sales data 2
91-94 sales data 3
and so on (each of the data points are 14 characters in width)
What is the read.fwf command that will extract these columns?


Some more details below. If you have any thoughts, please share with me.
Basically I want to do some analysis on how we are biased on our forecasts. I have several files as shown below. I have put one record each for the sales file and the forecast file. The file is fixed width format. THe first 62 characters is the key for the records. THis should be further broken down into several column values. For
A006004004016004016011 can be broken down as follows:
Category = A006,
BU = 004
Class = 004
Size = 016
BDC = 004016011

I then want to do  cbind on both of these dataframes and compare the statistical forecast and the actual sales for a given time window.

EXAMPLE RECORD FROM THE Sales file (columns truncated)
A005001024003000023100004231003030050303A006004004016004016011        23.200        23.700        22.800        23.300

Example record from the Stat Forecast file (columns truncated)
A005001024003000023100004231003030050303A006004004016004016051        34.800        35.500        34.200        34.900




More information about the R-help mailing list