Package 'cuadramelo'

Modify matrix by blocks

Description

Applies a function to a matrix by horizontal or vertical blocks.

Usage

apply_by_block(Y, layout, L, FUN, ...)

Arguments

Y	Matrix
layout	Blocks are distributed: 1 horizontally, 2 vertically.
L	Number of lines of the block.
FUN	Funtion to apply to the block.
...	Arguments to be passed to FUN.

Value

A matrix.

---

Balance matrix by blocks

Description

Applies balance_matrix() to equally-sized blocks that partition the matrix either vertically or horizontally.

Usage

balance_by_blocks(Y, col_totals = NULL, row_totals = NULL, layout, L)

Arguments

Y	Matrix to be balanced.
col_totals	Desired colSums for each block. See details.
row_totals	Desired rowSums for each block. See details.
layout	The blocks are distributed: 1 horizontally, 2 vertically.
L	Number of lines that a block encompasses.

Details

When Y is composed of **vertically** stacked blocks, col_totals must be a matrix whose rows are the colSums for each block, and row_totals just a (vertical) vector.

When Y is composed of blocks arraged **horizontally**, col_totals is a (horizontal) vector, and row_totals is a matrix whose columns are the rowSums for each block.

Value

The balanced matrix.

Examples

set.seed(10)
Y <- (rnorm(32)*10) |> matrix(ncol = 2) |> round(3)
v <- aggregate(Y, by = list(rep(1:4, times = rep(4,4))), FUN = sum)[, -1] |>
  round() |> as.matrix()
X <- balance_by_blocks(Y, v, layout = 2, L = 4)
U <- Y[5:8,] |> balance_matrix(v[2,])
X[5:8,] - U

---

Balance matrix

Description

Balances a matrix so that the columns and/or rows add up to a certain vector.

Usage

balance_matrix(Y, col_totals = NULL, row_totals = NULL, allow_negative = TRUE)

Arguments

Y	Matrix to be balanced.
col_totals	(optional) Desired sum of columns.
row_totals	(optional) Desired sum of rows.
allow_negative	Are negative entries in the balanced matrix allowed?

Details

Balancing is done according to the criteria of minimum sum of squares.

If neither col_totals nor row_totals is given, the same matrix will be returned. If only one of them is given, only that axis will be balanced.

Value

The balanced matrix.

Examples

set.seed(2)
Y <- rnorm(3*5) |> matrix(3,5) |> round(3)
v <- c( 0.876, -1.078, 3.452, 0.261, 1.349)
h <- c(-1.851, 0.243, 6.468)
X1 <- balance_matrix(Y, v, h)
Y
X1
h
rowSums(X1)
v
colSums(X1)
X3 <- balance_matrix(Y, col_totals = v)
v
colSums(X3)
X4 <- balance_matrix(Y, row_totals = h)
h
rowSums(X4)

---

Make non-negative

Description

Modifies as little as possible the entries of a matrix in order to make them non-negative, keeping row and column totals unchanged.

Usage

make_non_negative(Y, allowSlack = FALSE)

Arguments

Y	Matrix to be positivized.
allowSlack	Can colSums and rowSums be modified?

Value

A non-negative matrix, except if it is impossible to balance the matrix.

Examples

Y <- c(1,2,-1,1,
       2,2,3,1,
       1,1,-2,3) |>
       matrix(nrow = 3)
X <- make_non_negative(Y)
Y
X |> round(2)
rowSums(Y)
rowSums(X)
colSums(Y)
colSums(X)
set.seed(2)
Y <- rnorm(3*5) |> matrix(3,5) |> round(3)
Y
tryCatch(make_non_negative(Y), error = function(e) {
  print(e)
})
make_non_negative(Y, allowSlack = TRUE) |> round()

---

Round matrix by blocks

Description

Applies round_matrix() to equally-sized blocks that partition the matrix either vertically or horizontally.

Usage

round_by_blocks(Y, layout, L, digits = 0, MARGIN_BLOCK = 0)

Arguments

Y	Matrix.
layout	The blocks are distributed: 1 horizontally, 2 vertically.
L	Number of lines that a block encompasses.
digits	Number of decimal places to be rounded to.
MARGIN_BLOCK	For each block 0 Preserves the rounded colSums and rowSums. 1 Preserves the rounded rowSums independently of each other. 2 Preserves the rounded colSums independently of each other.

Value

The rounded matrix.

Examples

set.seed(10)
Y <- (rnorm(32)*10) |> matrix(ncol = 2) |> round(3)
X <- round_by_blocks(Y, 2, 4)
U <- Y[5:8,] |> round_matrix()
X[5:8,] - U

---

Round a matrix

Description

Returns an integer matrix that preserves the rounded colSums and rowSums.

Usage

round_matrix(Y, digits = 0, MARGIN = 0)

Arguments

Y	A matrix.
digits	Decimal places to round to.
MARGIN	One of 0 Preserves the rounded colSums and rowSums. 1 Preserves the rounded rowSums independently of each other. 2 Preserves the rounded colSums independently of each other.

Details

The function will throw a *warning* if the problem is infeasable. To be able to round the matrix in this fashion, the following things must be equal:

• the sum of the differences between the row totals and the rounded row totals

• the sum of the differences between the column totals and the rounded row totals

Value

The rounded matrix.

Examples

set.seed(6)
Y <- rnorm(3*5)*10 |> matrix(3,5) |> round(3)
X <- round_matrix(Y)
Y
X
colSums(Y) |> round()
colSums(X)
rowSums(Y) |> round()
rowSums(X)

---

Round univariate

Description

Rounds a vector preserving the rounded sum.

Usage

round_vector(x, digits = 0)

Arguments

x	A vector.
digits	Number of decimal places to be rounded to.

Value

description

Examples

set.seed(4)
x <- (rnorm(5)*10) |> abs()
y <- round_vector(x)
cbind(x, y)
round(sum(x)) - sum(y)

---