Mathematical Functions

Applies the Math group functions to spam objects

# ceiling(x)
# floor(x)
# exp(x, base = exp(1))
# log(x, base = exp(1))
# sqrt(x)

# abs(x)
# cumprod(x)
# cumsum(x)

# cos(x)
# sin(x)
# tan(x)

# acosh(x)

Arguments

x

spam object.

base

positive number. The base with respect to which logarithms are computed. Defaults to e=exp(1).

Value

If the option spam.structurebased=TRUE, all functions operate on the vector x@entries and return the result thereof.

Conversely, if structurebased=FALSE, the result is identical to one with as.matrix(x) input and an as.spam purger.

Details

It is important to note that the zero entries do not enter the evaluation when structurebased=FALSE. The operations are performed on the stored non-zero elements. This may lead to differences if compared with the same operation on a full matrix.

See also

Summary.spam, Ops.spam and Math2.spam

Author

Reinhard Furrer

Examples

getGroupMembers("Math")
#>  [1] "abs"      "sign"     "sqrt"     "ceiling"  "floor"    "trunc"   
#>  [7] "cummax"   "cummin"   "cumprod"  "cumsum"   "exp"      "expm1"   
#> [13] "log"      "log10"    "log2"     "log1p"    "cos"      "cosh"    
#> [19] "sin"      "sinh"     "tan"      "tanh"     "acos"     "acosh"   
#> [25] "asin"     "asinh"    "atan"     "atanh"    "cospi"    "sinpi"   
#> [31] "tanpi"    "gamma"    "lgamma"   "digamma"  "trigamma"

mat <- matrix(c( 1,2,0,3,0,0,0,4,5),3)
smat <- as.spam( mat)
cos( mat)
#>            [,1]       [,2]       [,3]
#> [1,]  0.5403023 -0.9899925  1.0000000
#> [2,] -0.4161468  1.0000000 -0.6536436
#> [3,]  1.0000000  1.0000000  0.2836622
cos( smat)
#>            [,1]       [,2]       [,3]
#> [1,]  0.5403023 -0.9899925  0.0000000
#> [2,] -0.4161468  0.0000000 -0.6536436
#> [3,]  0.0000000  0.0000000  0.2836622
#> Class 'spam' (32-bit)

options(spam.structurebased=FALSE)
cos( smat)
#>            [,1]       [,2]       [,3]
#> [1,]  0.5403023 -0.9899925  1.0000000
#> [2,] -0.4161468  1.0000000 -0.6536436
#> [3,]  1.0000000  1.0000000  0.2836622
#> Class 'spam' (32-bit)

sqrt( smat)
#>          [,1]     [,2]     [,3]
#> [1,] 1.000000 1.732051 0.000000
#> [2,] 1.414214 0.000000 2.000000
#> [3,] 0.000000 0.000000 2.236068
#> Class 'spam' (32-bit)