# [R] Is there a funct to sum differences?

Jeff Newmiller jdnewmil at dcn.davis.ca.us
Sat Dec 24 10:34:50 CET 2016

```Perhaps

rates\$experiment3  <- rates\$Int2 - rates\$Int2[ 1 ]

?

I still don't know what you think the numeric values this operation should  yield will be.
--
Sent from my phone. Please excuse my brevity.

On December 23, 2016 9:29:21 PM PST, arthur brogard <abrogard at yahoo.com> wrote:
>Yes, sorry about that.  I keep making mistakes I shouldn't make.
>
>
>You can ignore the finalone. I have been doing other work on this and
>it comes from there. I took the example from the R screen after it had
>run one of these other things that created the finalone.
>
>I guess I was thinking just seeing the data mentioned in the code was
>be enough.
>
>I don't want a function to do the division and multiplication.
>
>It's a function that will ".. automatically sum the difference between
>the first
>
> and subsequent to the end of a list? "  that I am looking for.
>
>I will try to explain, I know I often don't make myself clear:
>
>I'm using this diff() function.
>
>This 'diff()' function finds the difference between two adjoining
>entries and it applies itself to the whole list so that in an instant I
>can have a list of differences between any two adjoining.
>
>Then I can have a list of differences between any two with any
>specified gap - 'lag' it is called.
>Using the same function.
>
>Now I have them and do that.  Then I add them together to find the
>'lastone' which is the total difference for the period.
>
>
>Now here's the point:  that covers a period of two timespans, months,
>they are.
>
>if I want to cover a span of 24 months, say, then I would have to write
>this diff() function 24 times.
>
>what I'm doing is finding the difference between the starting point and
>every other point and then adding them all together.  bit like finding
>the area beneath the curve maybe.
>
> And that's what I want to do.
>
> :)
>
>
>
>
>
>
>
>
>
>----- Original Message -----
>From: Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
>To: arthur brogard <abrogard at yahoo.com>
>Cc: r-help at r-project.org
>Sent: Saturday, 24 December 2016, 15:34
>Subject: Re: [R] Is there a funct to sum differences?
>
>You need to "reply all" so other people can help as well, and others
>can
>
>I am still puzzled by how you expect to compute "finalone". If you had
>supplied numbers other than all 5's it might have been easier to figure
>
>out what is going on.
>
>What is your purpose in performing this calculation?
>
>#### reproducible code
>"Date          Int
>Jan-1959        5
>Feb-1959        5
>Mar-1959        5
>Apr-1959        5
>May-1959        5
>Jun-1959        5
>Jul-1959        5
>Aug-1959        5
>Sep-1959        5
>Oct-1959        5
>Nov-1959        5
>", header = TRUE, colClasses = c( "character", "numeric" ) )
>
>rates\$thisone <- c(diff(rates\$Int), NA)
>rates\$nextone <- c(diff(rates\$Int, lag=2), NA, NA)
>rates\$lastone <- (rates\$thisone + rates\$nextone)/6.5*1000
># I doubt there is a ready-built function that knows you want to
># divide by 6.5 or multiply by 1000
>
># form a vector from positions 2:11 and append NA)
>rates\$experiment1 <- rates\$Int + c( rates\$Int[ -1 ], NA )
># numbers that are not all the same
>rates\$Int2 <- (1:11)^2
>rates\$experiment2 <- rates\$Int2 + c( rates\$Int2[ -1 ], NA )
>
># dput(rates)
>result <- structure(list(Date = c("Jan-1959", "Feb-1959", "Mar-1959",
>"Apr-1959",
>"May-1959", "Jun-1959", "Jul-1959", "Aug-1959", "Sep-1959", "Oct-1959",
>"Nov-1959"), Int = c(5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5), thisone = c(0,
>0, 0, 0, 0, 0, 0, 0, 0, 0, NA), nextone = c(0, 0, 0, 0, 0, 0,
>0, 0, 0, NA, NA), lastone = c(0, 0, 0, 0, 0, 0, 0, 0, 0, NA,
>NA), Int2 = c(1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121), experiment1 =
>
>c(10,
>10, 10, 10, 10, 10, 10, 10, 10, 10, NA), experiment2 = c(5, 13,
>25, 41, 61, 85, 113, 145, 181, 221, NA)), .Names = c("Date",
>"Int", "thisone", "nextone", "lastone", "Int2", "experiment1",
>"experiment2"), row.names = c(NA, -11L), class = "data.frame")
>
>On Sat, 24 Dec 2016, arthur brogard wrote:
>
>>
>>
>> Yes, sure, thanks for your interest.  I apologise for not submitting
>in the correct manner.  I'll learn (I hope).
>>
>> Here's the source - a spreadsheet with just two columns, date and
>'Int'.
>>
>>
>> Date    Int
>> Jan-1959    5
>> Feb-1959    5
>> Mar-1959    5
>> Apr-1959    5
>> May-1959    5
>> Jun-1959    5
>> Jul-1959    5
>> Aug-1959    5
>> Sep-1959    5
>> Oct-1959    5
>> Nov-1959    5
>>
>>
>> After processing it becomes this:
>>
>>
>>> rates
>> Date   Int thisone nextone     lastone finalone
>> 1   1959-01-01  5.00    0.00    0.00    0.000000       10
>> 2   1959-02-01  5.00    0.00    0.00    0.000000       10
>> 3   1959-03-01  5.00    0.00    0.00    0.000000       10
>> 4   1959-04-01  5.00    0.00    0.00    0.000000       10
>> 5   1959-05-01  5.00    0.00    0.00    0.000000       10
>> 6   1959-06-01  5.00    0.00    0.00    0.000000       10
>>
>> The one long column I'm referring to is the 'Int' column which R has
>imported.
>>
>> The actual code is:
>>
>>
>TRUE,colClasses=c("character","numeric"))
>>
>> sapply(rates,class)
>>
>> rates\$Date <- strptime(paste0("1-", rates\$Date), format="%d-%b-%Y",
>tz="UTC")
>>
>>
>> rates\$thisone <- c(diff(rates\$Int), NA)
>> rates\$nextone <- c(diff(rates\$Int, lag=2), NA, NA)
>> rates\$lastone <- (rates\$thisone + rates\$nextone)/6.5*1000
>>
>>
>> rates
>>
>>
>>
>> ab
>>
>>
>>
>> ----- Original Message -----
>> From: Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
>> To: arthur brogard <abrogard at yahoo.com>; arthur brogard via R-help
><r-help at r-project.org>; "r-help at r-project.org" <r-help at r-project.org>
>> Sent: Saturday, 24 December 2016, 13:25
>> Subject: Re: [R] Is there a funct to sum differences?
>>
>> Could you make your example reproducible? That is, include some
>sample input and output. You talk about a column of numbers and then
>you seem to work with named lists and I can't reconcile your words with
>the code I see.
>> --
>> Sent from my phone. Please excuse my brevity.
>>
>>
>> On December 23, 2016 3:40:18 PM PST, arthur brogard via R-help
><r-help at r-project.org> wrote:
>>> I've been looking but I can't find a function to sum difference.
>>>
>>> I have this code:
>>>
>>>
>>> rates\$thisone <- c(diff(rates\$Int), NA)
>>> rates\$nextone <- c(diff(rates\$Int, lag=2), NA, NA)
>>> rates\$lastone <- (rates\$thisone + rates\$nextone)
>>>
>>>
>>> It is looking down one long column of numbers.
>>>
>>> It sums the difference between the first two and then between the
>first
>>> and third and so on.
>>>
>>> Can it be made to automatically sum the difference between the first
>>> and subsequent to the end of a list?
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>---------------------------------------------------------------------------
>Jeff Newmiller                        The     .....       .....  Go
>Live...
>DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live
>Go...
>                                     Live:   OO#.. Dead: OO#..  Playing
>Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
>/Software/Embedded Controllers)               .OO#.       .OO#.
>rocks...1k
>
>---------------------------------------------------------------------------

```