# symnum

##### Symbolic Number Coding

Symbolically encode a given numeric or logical vector or array. Particularly useful for visualization of structured matrices, e.g., correlation, sparse, or logical ones.

##### Usage

```
symnum(x, cutpoints = c(0.3, 0.6, 0.8, 0.9, 0.95),
symbols = if(numeric.x) c(" ", ".", ",", "+", "*", "B")
else c(".", "|"),
legend = length(symbols) >= 3,
na = "?", eps = 1e-5, numeric.x = is.numeric(x),
corr = missing(cutpoints) && numeric.x,
show.max = if(corr) "1", show.min = NULL,
abbr.colnames = has.colnames,
lower.triangular = corr && is.numeric(x) && is.matrix(x),
diag.lower.tri = corr && !is.null(show.max))
```

##### Arguments

- x
- numeric or logical vector or array.
- cutpoints
- numeric vector whose values
`cutpoints[j]`

$= c_j$ (*after*augmentation, see`corr`

below) are used for intervals. - symbols
- character vector, one shorter than (the
*augmented*, see`corr`

below)`cutpoints`

.`symbols[j]`

$= s_j$ are used ascode for the (half open) interval $(c_j,c_{j+1}]$.When

`numeric.x`

is`FALSE`

, i.e., by default when argument`x`

is`logical`

, the default is`c(".","|")`

(graphical 0 / 1 s). - legend
- logical indicating if a
`"legend"`

attribute is desired. - na
- character or logical. How
`NAs`

are coded. If`na == FALSE`

,`NA`

s are coded invisibly,*including*the`"legend"`

attribute below, which otherwise mentions NA coding. - eps
- absolute precision to be used at left and right boundary.
- numeric.x
- logical indicating if
`x`

should be treated as numbers, otherwise as logical. - corr
- logical. If
`TRUE`

,`x`

contains correlations. The cutpoints are augmented by`0`

and`1`

and`abs(x)`

is coded. - show.max
- if
`TRUE`

, or of mode`character`

, the maximal cutpoint is coded especially. - show.min
- if
`TRUE`

, or of mode`character`

, the minimal cutpoint is coded especially. - abbr.colnames
- logical, integer or
`NULL`

indicating how column names should be abbreviated (if they are); if`NULL`

(or`FALSE`

and`x`

has no column names), the column names will all be empty, i.e.,`""`

; otherwise if`abbr.colnames`

is false, they are left unchanged. If`TRUE`

or integer, existing column names will be abbreviated to`abbreviate(*, minlength = abbr.colnames)`

. - lower.triangular
- logical. If
`TRUE`

and`x`

is a matrix, only the*lower triangular*part of the matrix is coded as non-blank. - diag.lower.tri
- logical. If
`lower.triangular`

*and*this are`TRUE`

, the*diagonal*part of the matrix is shown.

##### Value

- An atomic character object of class
`noquote`

and the same dimensions as`x`

.If

`legend`

is`TRUE`

(as by default when there are more than two classes), the result has an attribute`"legend"`

containing a legend of the returned character codes, in the form $$c_1 s_1 c_2 s_2 \dots s_n c_{n+1}$$ where $c_j$`= cutpoints[j]`

and $s_j$`= symbols[j]`

.

##### Note

The optional (mostly logical) arguments all try to use smart defaults. Specifying them explicitly may lead to considerably improved output in many cases.

##### concept

matrix visualization

##### See Also

##### Examples

`library(stats)`

```
ii <- setNames(0:8, 0:8)
symnum(ii, cut = 2*(0:4), sym = c(".", "-", "+", "$"))
symnum(ii, cut = 2*(0:4), sym = c(".", "-", "+", "$"), show.max = TRUE)
symnum(1:12 %% 3 == 0) # --> "|" = TRUE, "." = FALSE for logical
## Pascal's Triangle modulo 2 -- odd and even numbers:
N <- 38
pascal <- t(sapply(0:N, function(n) round(choose(n, 0:N - (N-n)%/%2))))
rownames(pascal) <- rep("", 1+N) # <-- to improve "graphic"
symnum(pascal %% 2, symbols = c("", "A"), numeric = FALSE)
##-- Symbolic correlation matrices:
symnum(cor(attitude), diag = FALSE)
symnum(cor(attitude), abbr. = NULL)
symnum(cor(attitude), abbr. = FALSE)
symnum(cor(attitude), abbr. = 2)
symnum(cor(rbind(1, rnorm(25), rnorm(25)^2)))
symnum(cor(matrix(rexp(30, 1), 5, 18))) # <<-- PATTERN ! --
symnum(cm1 <- cor(matrix(rnorm(90) , 5, 18))) # < White Noise SMALL n
symnum(cm1, diag = FALSE)
symnum(cm2 <- cor(matrix(rnorm(900), 50, 18))) # < White Noise "BIG" n
symnum(cm2, lower = FALSE)
## NA's:
Cm <- cor(matrix(rnorm(60), 10, 6)); Cm[c(3,6), 2] <- NA
symnum(Cm, show.max = NULL)
## Graphical P-values (aka "significance stars"):
pval <- rev(sort(c(outer(1:6, 10^-(1:3)))))
symp <- symnum(pval, corr = FALSE,
cutpoints = c(0, .001,.01,.05, .1, 1),
symbols = c("***","**","*",".",""))
noquote(cbind(P.val = format(pval), Signif = symp))
```

*Documentation reproduced from package stats, version 3.3, License: Part of R 3.3*