[R] Calculating frequencies of multiple values in 200 colomns

Bert Gunter bgunter.4567 at gmail.com
Fri Nov 10 00:51:35 CET 2017


Always reply to the list. I am not a free, private consultant!

"For example, if I have the values : 1 , 2 , 3 in each column, applying
Tabulate () would calculate the frequency of 1 and 2 without 3"

Huh??

> x <- sample(1:3,10,TRUE)
> x
 [1] 1 3 1 1 1 3 2 3 2 1
> tabulate(x)
[1] 5 2 3

Cheers,
Bert



Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Thu, Nov 9, 2017 at 3:44 PM, Allaisone 1 <allaisone1 at hotmail.com> wrote:

> Thank you so much for your replay
>
>
> Actually, I tried apply() function but struggled with the part of writing
> the appropriate function inside it which calculate the frequency of the 3
> values. Tabulate () function is a good start but the problem is that this
> calculates the frequency of two values only per column which means that
> when I apply maf () function , maf value will be calculated using the
> frequency of these 2 values only without considering the frequency of the
> 3rd value. For example, if I have the values : 1 , 2 , 3 in each column,
> applying Tabulate () would calculate the frequency of 1 and 2 without 3 . I
> need a way to calculate the frequencies of all of the 3 values so the
> calculation of maf will be correct as it will consider all the 3
> frequencies but not only 2 .
>
>
> Regards
>
> Allahisone
> ------------------------------
> *From:* Bert Gunter <bgunter.4567 at gmail.com>
> *Sent:* 09 November 2017 20:56:39
> *To:* Allaisone 1
> *Cc:* r-help at R-project.org
> *Subject:* Re: [R] Calculating frequencies of multiple values in 200
> colomns
>
> This is not a good way to do things! R has many powerful built in
> functions to do this sort of thing for you. Searching  -- e.g. at
> rseek.org or even a plain old google search -- can help you find them.
> Also, it looks like you need to go through a tutorial or two to learn more
> about R's basic functionality.
>
> In this case, something like (no reproducible example given, so can't
> confirm):
>
> apply(Values, 2, function(x)maf(tabulate(x)))
>
> should be close to what you want .
>
>
> Cheers,
> Bert
>
>
>
>
>
>
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along and
> sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
> On Thu, Nov 9, 2017 at 11:44 AM, Allaisone 1 <allaisone1 at hotmail.com>
> wrote:
>
>>
>> Hi All
>>
>>
>> I have a dataset of 200 columns and 1000 rows , there are 3 repeated
>> values under each column (7,8,10). I wanted to calculate the frequency of
>> each value under each column and then apply the function maf () given that
>> the frequency of each value is known. I can do the analysis step by step
>> like this :-
>>
>>
>> > Values
>>
>>
>>          A       B       C       ... 200
>>
>> 1      7       10      7
>>
>> 2      7       8        7
>>
>> 3      10     8        7
>>
>> 4       8      7         10
>>
>> .
>>
>> .
>>
>> .
>>
>> 1000
>>
>>
>> For column A : I calculate the frequency for the 3 values as follows :
>>
>>  count7 <- length(which(Values$A == 7))
>>
>> count8 <- length(which(Values$A == 8))
>>
>> count10 <- length(which(Values$A == 10))
>>
>>
>> count7 = 2, count8 = 1 , count10= 1.
>>
>>
>> Then, I create a vector  and type the frequencies manually :
>>
>>
>>  Freq<- c( count7=2  ,count8= 1,count10=1)
>>
>>
>> Then I apply the function maf ()  :-
>>
>> maf(Freq)
>>
>>
>> This gives me the result I need for column A , could you please help me
>>
>> to perform the analysis for all of the 200 columns at once ?
>>
>>
>> Regards
>>
>> Allahisone
>>
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posti
>> ng-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>

	[[alternative HTML version deleted]]



More information about the R-help mailing list