explain ICD9 codes
Description
convert 'decimal' format (123.45 style) ICD9 codes into the name and description for human review there are official ICD9CM data tables, not with conversion to decimal notation, but to the textual format.
Usage
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23  icd9Explain(icd9, isShort = icd9GuessIsShort(icd9), doCondense = TRUE,
brief = FALSE, warn = TRUE)
icd9ExplainShort(icd9Short, doCondense = TRUE, brief = FALSE, warn = TRUE)
icd9ExplainDecimal(icd9Decimal, doCondense = TRUE, brief = FALSE,
warn = TRUE)
## S3 method for class 'list'
icd9Explain(icd9, isShort = icd9GuessIsShort(icd9),
doCondense = TRUE, brief = FALSE, warn = TRUE)
## S3 method for class 'factor'
icd9Explain(icd9, isShort = icd9GuessIsShort(icd9),
doCondense = TRUE, brief = FALSE, warn = TRUE)
## S3 method for class 'character'
icd9Explain(icd9, isShort = icd9GuessIsShort(icd9),
doCondense = TRUE, brief = FALSE, warn = TRUE)
## S3 method for class 'numeric'
icd9Explain(icd9, isShort = icd9GuessIsShort(icd9),
doCondense = TRUE, brief = FALSE, warn = FALSE)

Arguments
icd9 
is a character vector or factor of ICD9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010". 
isShort 
single logical value which determines whether the ICD9 code provided is in short (TRUE) or decimal (FALSE) form. Where reasonable, this is guessed from the input data. 
doCondense 
single logical value which indicates whether to condense the given set of ICD9 codes by replacing subsets of codes with 'parent' codes which exactly encompass certain subsets. E.g. If all cholera diagnoses are provided, only '001  Cholera' needs to be displayed, not all subtypes. 
brief 
single logical value, default is 
warn 
single logical value, default is 
icd9Short 
is a character vector of ICD9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010" 
icd9Decimal 
character vector of ICD9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010" 
Value
data frame, or list of data frames, with fields for ICD9 code, name and description, derived from datamart lookup table
Methods (by class)

list
: explain all ICD9 codes in a list of vectors 
factor
: explain factor of ICD9 codes 
character
: explain character vector of ICD9 codes 
numeric
: explain numeric vector of ICD9 codes, with warning. In general, this is not allowed because of the possible ambiguity of numeric decimal codes, but for convenience, this is allowed in this case to avoid typing many quotes.
See Also
package comorbidities
Examples
1 2  icd9ExplainShort(ahrqComorbid[[1]][1:3])
icd9Explain(ahrqComorbid[[1]][1:3], brief = TRUE)
