Math.sparse3Darray {spatstat.sparse}

S3 Group Generic Methods for Sparse Three-Dimensional Arrays

Description

Group generic methods which make it possible to apply the familiar mathematical operators and functions to sparse three-dimensional arrays (objects of class "sparse3Darray"). See Details for a list of implemented functions.

Usage

## S3 methods for group generics have prototypes:
Math(x, ...)
Ops(e1, e2)
Complex(z)
Summary(..., na.rm=FALSE)

Arguments

x, z, e1, e2

Sparse three-dimensional arrays (objects of class "sparse3Darray"). Alternatively e1 or e2 can be a single scalar, vector, sparse vector, matrix or sparse matrix.

...

further arguments passed to methods.

na.rm

Logical value specifying whether missing values should be removed.

Details

These group generics make it possible to perform element-wise arithmetic and logical operations with sparse three-dimensional arrays, or apply mathematical functions element-wise, or compute standard summaries such as the mean and maximum.

Below is a list of mathematical functions and operators which are defined for sparse 3D arrays.

1. Group "Math":

   • abs, sign, sqrt,
     floor, ceiling, trunc,
     round, signif

   • exp, log, expm1, log1p,
     cos, sin, tan,
     cospi, sinpi, tanpi,
     acos, asin, atan

     cosh, sinh, tanh,
     acosh, asinh, atanh

   • lgamma, gamma, digamma, trigamma

   • cumsum, cumprod, cummax, cummin

2. Group "Ops":

   • "+", "-", "*", "/", "^", "%%", "%/%"

   • "&", "|", "!"

   • "==", "!=", "<", "<=", ">=", ">"

3. Group "Summary":

   • all, any

   • sum, prod

   • min, max

   • range

4. Group "Complex":

   • Arg, Conj, Im, Mod, Re

Value

The result of group "Math" functions is another three-dimensional array of the same dimensions as x, which is sparse if the function maps 0 to 0, and otherwise is a full three-dimensional array.

The result of group "Ops" operators is another three-dimensional array of the same dimensions as e1 and e2, which is sparse if both e1 and e2 are sparse.

The result of group "Complex" functions is another sparse three-dimensional array of the same dimensions as z.

The result of group "Summary" functions is a logical value or a numeric value or a numeric vector of length 2.

Author(s)

Adrian Baddeley [e-mail], Rolf Turner [e-mail] and Ege Rubak [e-mail].

See Also

sparse3Darray, tensorSparse

Examples

  M <- sparse3Darray(i=1:4, j=sample(1:4, replace=TRUE),
                     k=c(1,2,1,2), x=1:4, dims=c(5,5,2))
  negM <- -M
  twoM <- M + M
  Mplus <- M + 1 ## not sparse!
  posM <- (M > 0)
  range(M)
  sinM <- sin(M)
  cosM <- cos(M) ## not sparse!
  expM1 <- expm1(M)