histFromSum {FSA} R Documentation

## Create a histogram from a frequency table.

### Description

Creates a histogram from values in a frequency table. Primarily used with already summarized length frequency data.

### Usage

```histFromSum(x, ...)

## Default S3 method:
histFromSum(x, y, ...)

## S3 method for class 'table'
histFromSum(x, ...)

## S3 method for class 'formula'
histFromSum(x, data = NULL, ...)
```

### Arguments

 `x` A numeric vector of bin/category values, a formula of the form `freq~cat` where `freq` contains the count/frequency values and `cat` contains the bin/category values, an object of class `table` from `table()` or `xtabs()`. `...` Additional arguments for `hist`. `y` A numeric vector of count/frequency values. `data` A data.frame that contains the `freq` and `cat` variables if a formula is given in `x`.

### Details

Creates a histogram fro values in a frequency table. The frequency table may be constructed from `xtabs`, `table`, or be in the form of a matrix or a data.frame (as if read in from an external data file).

### Value

None, but a graphic is created.

### Author(s)

Derek H. Ogle, derek@derekogle.com

See `hist` and `hist.formula` for related functionality.

### Examples

```## Make some dummy data with a length category variable
set.seed(634434789)
df <- data.frame(tl=round(rnorm(100,100,20)))
df\$lcat10 <- lencat(df\$tl,w=10)

## Summarize as tables
( tbl1 <- xtabs(~lcat10,data=df) )
( tbl2 <- table(df\$lcat10) )

## Turn the tables into a data.frame for testing (convert
## the categories variables to numeric with fact2num())
df2 <- data.frame(tbl1)
df2\$lcat10 <- fact2num(df2\$lcat10)

## Turn the table into a matrix for testing
( mat1 <- cbind(lcat10=as.numeric(rownames(tbl1)),freq=tbl1) )

## Histogram of the raw data ... set breaks and x-axis label
brks <- seq(20,160,10)
xlbl <- "Total Length (mm)"
hist(~tl,data=df,breaks=brks,xlab=xlbl)

## Use this function with various inputs ... changed colors
## on each plot so that it was obvious that a new plot was made.
# table from xtabs()
histFromSum(tbl1,breaks=brks,xlab=xlbl,col="gray75")
# table from table()
histFromSum(tbl2,breaks=brks,xlab=xlbl,col="gray70")
# vectors from data.frame
histFromSum(df2\$lcat10,df2\$Freq,breaks=brks,xlab=xlbl,col="gray65")
# vectors from matrix
histFromSum(mat1[,"lcat10"],mat1[,"freq"],breaks=brks,xlab=xlbl,col="gray60")
# formula from a data.frame
histFromSum(Freq~lcat10,data=df2,breaks=brks,xlab=xlbl,col="gray55")

```

[Package FSA version 0.8.26.9000 Index]