compareVersion Compare Two Package Version Numbers
 Description
Compare two package version numbers to see which is later.
Usage
compareVersion(a, b)
Arguments
| a, b | Character strings representing package version numbers. | 
Details
R package version numbers are of the form x.y-z for integers x, y and z, with components after x optionally missing (in which case the version number is older than those with the components present). 
Value
0 if the numbers are equal, -1 if b is later and 1 if a is later (analogous to the C function strcmp). 
See Also
package_version, library, packageStatus. 
Examples
compareVersion("1.0", "1.0-1")
compareVersion("7.2-0","7.1-12")
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Licensed under the GNU General Public License.