Create a histogram from a frequency table.

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

Usage

histFromSum(x, ...)

# S3 method for default
histFromSum(x, y, ...)

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

# S3 method for 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.

Value

None, but a graphic is created.

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).

See also

See hist and hist.formula for related functionality.

Author

Derek H. Ogle, DerekOgle51@gmail.com

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) )
#> lcat10
#>  20  50  60  70  80  90 100 110 120 130 140 150 
#>   1   1   5   7  10  24  19  19   7   3   3   1 
( tbl2 <- table(df$lcat10) )
#> 
#>  20  50  60  70  80  90 100 110 120 130 140 150 
#>   1   1   5   7  10  24  19  19   7   3   3   1 

## 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) )
#>     lcat10 freq
#> 20      20    1
#> 50      50    1
#> 60      60    5
#> 70      70    7
#> 80      80   10
#> 90      90   24
#> 100    100   19
#> 110    110   19
#> 120    120    7
#> 130    130    3
#> 140    140    3
#> 150    150    1

## 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")