[R] Getting the values out of histogram (lattice)

[Rolf Turner]

'Scuse me, but I don't see anything in your example relating to what the OP
asked for. She wanted to get at the ``actual data defining the 
histogram'', which
I interpret as meaning the bar heights (the percentages, density values, 
or counts,
depending on "type"). These do not appeared to be stored in the object 
returned
by histogram().

cheers,

Rolf Turner

On 01/09/11 10:59, Duncan Mackay wrote:
> Hi Monica
>
> An example abbreviated from ?histogram
>
> x = histogram( ~ height, data = singer)
>
> names(x)
> # to see what is there
> str(x)
>
> # information
> x$panel.args.common
> $breaks
> [1] 59.36 61.28 63.20 65.12 67.04 68.96 70.88 72.80 74.72 76.64
>
> $type
> [1] "percent"
>
> $equal.widths
> [1] TRUE
>
> $nint
> [1] 9
>
> # x$panel.args: name as number
> x[[35]]
> [[1]]
> [[1]]$x
> [1] 64 62 66 65 60 61 65 66 65 63 67 65 62 65 68 65 63 65 62 65 66 62 
> 65 63 65 66 65 62 65 66 65 61 65 66 65 62 63 67 60 67 66 62 65 62
> [45] 61 62 66 60 65 65 61 64 68 64 63 62 64 62 64 65 60 65 70 63 67 66 
> 65 62 68 67 67 63 67 66 63 72 62 61 66 64 60 61 66 66 66 62 70 65
> [89] 64 63 65 69 61 66 65 61 63 64 67 66 68 70 65 65 65 64 66 64 70 63 
> 70 64 63 67 65 63 66 66 64 64 70 70 66 66 66 69 67 65 69 72 71 66
> [133] 76 74 71 66 68 67 70 65 72 70 68 64 73 66 68 67 64 68 73 69 71 
> 69 76 71 69 71 66 69 71 71 71 69 70 69 68 70 68 69 72 70 72 69 73 71
> [177] 72 68 68 71 66 68 71 73 73 70 68 70 75 68 71 70 74 70 75 75 69 
> 72 71 70 71 68 70 75 72 66 72 70 69 72 75 67 75 74 72 72 74 72 72 74
> [221] 70 66 68 75 68 70 72 67 70 70 69 72 71 74 75
>
> etc to suite your requirements
>
> HTH
>
> Regards
>
> Duncan
>
>
> Duncan Mackay
> Department of Agronomy and Soil Science
> University of New England
> ARMIDALE NSW 2351
> Email: home mackay at northnet.com.au
>
>
>
> At 23:50 31/08/2011, you wrote:
>
>
>
>> Hi,
>>
>>
>>
>> I have a relatively big dataset and I want to construct
>> some histograms using the histogram function in lattice. One thing I am
>> interested in is to look at differences between density and percent. 
>> I know I can
>> use the hist function but it seems that this function gives sometimes 
>> some
>> wrong answers and the density is actually a percent since it is 
>> calculated as counts in the bin divided by the total no. of points. 
>> Let me explain.
>>
>>
>>
>> If I let the hist function to decide the breaks, or I use
>> a small number, or one of the pre-determined methods to select breaks 
>> then
>> everything seems to be in order. But if I decide to use ­ for example 
>> ­ 100 as
>> a breaks (I have over 90000 data points so the number of breaks is not
>> necessarily too large I would think) the density for the first bin is 
>> over 1,
>> although for all the other breaks the density is actually a percent 
>> since it is
>> the count for that bin divided by the total no. of points I have. So 
>> …. Here it
>> is something wrong or most probably I am doing something wrong.
>>
>>
>>
>> If I use the function histogram from lattice it is
>> obvious that there is a difference between the percent param and the 
>> density
>> param. I looked at the function code and I didn't understand it ­ to 
>> be honest.
>> It seems it calls inside the hist function, or a slightly modify 
>> variant of
>> hist. Reading about the object trellis I saw I can access different 
>> info about
>> the graph it generates but nothing about the actual data that goes into
>> defining the histogram. How can I access the data from it?
>>
>>
>>
>> I am not sure if my problem is platform specific ­ it should
>> not be ­ but I have Rx64 2.13.1 on windows machine, in case it counts.
>>
>>
>>
>> I appreciate your help, thanks,
>>
>>
>>
>> Monica
>>
>>
>> ______________________________________________
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>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>