[R] how to enter frequency type data in R with class intervals

David Winsemius
2011-01-30T16:18:40Z

On Jan 30, 2011, at 5:48 AM, arindam fadikar wrote:

> Dear all,
>
> Given data of a continuous frequency distribution with class
> intervals ..
> how to enter such data so that we can use the normal mean, median
> and mode
> functions to calculate them and also can draw histogram ..
>
> for example how to enter this data in R
>
>  Height range[image:
> ?]<http://en.wikipedia.org/wiki/Frequency_distribution#> Number
> of students[image: ?]
> <http://en.wikipedia.org/wiki/Frequency_distribution#> Cumulative
> number[image: ?] <http://en.wikipedia.org/wiki/
> Frequency_distribution#> 4.5?5.0
> feet 25 25 5.0?5.5 feet 35 60 5.5?6 feet 20 80 6.0?6.5 feet 20
> 100

The textConnection function allows you to simulate file input from
material cut and pasted from text sources:

 > dtabl <- read.table(textConnection("4.5?5.0 feet 25 25 \n5.0?5.5
feet 35 60 \n5.5?6 feet 20 80 \n6.0?6.5 feet 20 100"),
header=FALSE, stringsAsFactors=FALSE)
 > names(dtabl) <- c("Interval", "units",
"Freq", "Cum_Freq")
 > dtabl
   Interval units Freq Cum_Freq
1  4.5?5.0  feet   25       25
2  5.0?5.5  feet   35       60
3    5.5?6  feet   20       80
4  6.0?6.5  feet   20      100

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--
David Winsemius, MD
West Hartford, CT