Oct 21, 2015
Oct 19, 2014
Suppose you have a triangle in Excel that you would like to analyze in R. In Excel, select the cells comprising the triangle including the labels identifying accident year and age and copy to the clipboard.
Back in R, load the excelRio package and run the function that pastes content from the clipboard. Be sure to tell the function that your data has a “header” for the column names (development ages) and a “rowheader” for the row names (accident years).
library(excelRio) tri <- pasteFromExcel(header = TRUE, rowheader = TRUE) tri 12 24 36 48 60 2010 1000 1200 1320 1386 1414 2011 1200 1452 1568 1631 NA 2012 800 1040 1113 NA NA 2013 1100 1320 NA NA NA 2014 850 NA NA NA NA
excelRio has special handling to strip out the dollar signs and commas when appropriate. excelRio’s interpretation of “appropriate” is, if after stripping out the dollar signs and commas the column of results can be successfully converted to numeric, then that’s what will happen. Without special handling, this would not normally happen, as below when the first two character elements lose numeric value.
as.numeric(c("$1,000", "1,200", "800"))  NA NA 800 Warning message: NAs introduced by coercion
The argument that controls this special handling is convertFormattedNumbers and can be turned off, as in the code below. Note that I also set stringsAsFactors = FALSE because my installation of R has the default value TRUE for that global option.
tri <- pasteFromExcel(header = TRUE, rowheader = TRUE, convertFormattedNumbers = FALSE, stringsAsFactors = FALSE) tri 12 24 36 48 60 2010 " $1,000 " " $1,200 " " $1,320 " " $1,386 " " $1,414 " 2011 " 1,200 " " 1,452 " " 1,568 " " 1,631 " NA 2012 " 800 " " 1,040 " " 1,113 " NA NA 2013 " 1,100 " " 1,320 " NA NA NA 2014 " 850 " NA NA NA NA mode(tri)  "character" class(tri)  "matrix"
The class of the above raises a subtle point about the value of the result from pasteFromExcel.
Data in Excel is often comprised of columns of data of many different types: numeric, character, and dates, to name a few. By default, therefore, pasteFromExcel will create a data.frame, an R object that allows differently typed columns. But when all the columns of data are “compatible,” pasteFromExcel will return a matrix object of the common “type” (or “mode”) by default, if possible, under the assumption that a matrix object would be “intuitively expected.” The argument that controls that option is simplify. By calling the function with simplify = FALSE, a data.frame will always be returned.
For more information about pasteFromExcel and its various optional arguments, see
Finally, Dear Reader, I leave you with a warning and a request for assistance! :)
Warning! excelRio’s special currency handling will only work with dollar signs, with periods as decimal separator, and with commas separating triples. I apologize. :(
(For the curious, excelRio stores its current regex pattern for currency in the variable currencypattern on line 38 in the file excelRio.r in the R folder of the package on github. )
Request for Assistance!
If anyone is interested in suggesting a currency pattern for their location I would really appreciate the collaboration — woohoo!! You can reach me at danielmarkmurphy at gmail. Thank you sincerely in advance.
created (mostly) with RMarkdown in RStudio
Oct 6, 2014
This week the Frys.com Open golf tournament takes place at the Silverado Resort and Spa in Napa, California. Besides volunteering as Shotlink operators, AIM supporters will also be manning a booth. Come on by to learn more and meet some nice mathematicians!
Oct 5, 2014
Aug 28, 2013
In simplest form, the Bornhuetter-Ferguson ("BF") Method estimates IBNR for an accident/policy/underwriting/origin year (tranch of exposure) as the product of an a-priori estimate of ultimate loss for that exposure and an estimate of the percent of that ultimate loss unknown/unreported/undeveloped at the time: