[R] Re : Indexing array to 1000

David Winsemius dwinsemius at comcast.net
Sun May 23 15:03:08 CEST 2010


On May 22, 2010, at 10:48 PM, Mohan L wrote:

> Dear All,
>
> I have an array some thing like this:
>
>> avglog
>  January  February     March     April       May      June      July
> August September
>    60102     83397     56774     48785     49010     40572     38175
> 47037 51402
>
> The class of "avglog" array.
>> class(avglog)
> [1] "array"
>
>> str(avglog)
> num [1:9(1d)] 60102 83397 56774 48785 49010 ...
> - attr(*, "dimnames")=List of 1
>  ..$ : chr [1:9] "January" "February" "March" "April" ...
>
> I have to normalize this "avglog" array to 1000. I mean, I need to  
> devide
> 1000/avglog[1] and have to multiply this to all the elements in the  
> array
> and need to plot graph Month Vs Index. To achive this I am doing the  
> below
> code. I am feeling there may be a simple way to do this.

This would accomplish those two goals in two lines:

 > plot(normedavlog <- 1000*avlog/avlog[1], xaxt="n")
 > axis(1, at=1:9, labels =names(avlog))

-- 
David.

>
>> value <- matrix (avglog)
>
>> value
>       [,1]
> [1,] 60102
> [2,] 83397
> [3,] 56774
> [4,] 48785
> [5,] 49010
> [6,] 40572
> [7,] 38175
> [8,] 47037
> [9,] 51402
>
>> day1Avg <- value[1]
>> day1Avg
> [1] 60102
>> ID <- (1000/day1Avg)
>> ID
> [1] 0.01663838
>> index <- value*ID
>> index
>           [,1]
> [1,] 1000.0000
> [2,] 1387.5911
> [3,]  944.6275
> [4,]  811.7034
> [5,]  815.4471
> [6,]  675.0524
> [7,]  635.1702
> [8,]  782.6195
> [9,]  855.2461
>
>> monthcount <- length(avglog)
>
>> Month <-  c(1:monthcount)
>
>> trend <- cbind(Month,c(index))
>
>> colnames(trend) <- c("Month","Index")
>
>> trend
>       Month  Index
> [1,]    1 1000.0000
> [2,]    2 1387.5911
> [3,]    3  944.6275
> [4,]    4  811.7034
> [5,]    5  815.4471
> [6,]    6  675.0524
> [7,]    7  635.1702
> [8,]    8  782.6195
> [9,]    9  855.2461
>
> any help will be greatly appreciated.
>
> Thanks & Rg
> Mohan L
>
> 	[[alternative HTML version deleted]]
>
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David Winsemius, MD
West Hartford, CT



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