Math-methods.RdGeneric mathematical functions that can be used with a Raster* object as argument:
"abs", "sign", "sqrt", "ceiling", "floor", "trunc",  "cummax", "cummin", 
"cumprod", "cumsum", "log", "log10", "log2", "log1p", "acos", "acosh", "asin", 
"asinh", "atan", "atanh", "exp", "expm1", "cos", "cosh", "sin", "sinh", "tan", "tanh".
You can use the, somewhat more flexible, function calc instead of the Math-methods.