This function checks if a string is a valid CAS registry number. A valid CAS is 1) separated by two hyphes into three parts; 2) the first part consists from two up to seven digits; 3) the second of two digits; 4) the third of one digit (check digit); 5) the check digits corresponds the checksum. The checksum is found by taking the last digit (excluding the check digit) multiplyingit with 1, the second last multiplied with 2, the third-last multiplied with 3 etc. The modulo 10 of the sum of these is the checksum.
is.cas(x, verbose = getOption("verbose"))
character; input CAS
logical; print messages during processing to console?
This function can only handle one CAS string
Eduard Szöcs, Tamás Stirling, Eric R. Scott, Andreas Scharmüller, Ralf B. Schäfer (2020). webchem: An R Package to Retrieve Chemical Information from the Web. Journal of Statistical Software, 93(13). doi: 10.18637/jss.v093.i13.
is.cas('64-17-5') is.cas('64175') is.cas('4-17-5') is.cas('64-177-6') is.cas('64-17-55') is.cas('64-17-6')
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.