Databases
StackOverflow2013
Postsdbo
POHow to get the difference in value between subsequent observations (country-years)?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to get the difference in value between subsequent observations (country-years)?
    primarykey
    data
    text
    <p>Let's say, I have scores for 5 countries over a period of 10 years such as:</p> <pre><code>mydata&lt;-1:3 mydata&lt;-expand.grid( country=c('A', 'B', 'C', 'D', 'E'), year=c('1980','1981','1982','1983','1984','1985','1986','1987','1988','1989')) mydata$score=sapply(runif(50,0,2), function(x) {round(x,4)}) library(reshape) mydata&lt;-reshape(mydata, v.names="score", idvar="year", timevar="country", direction="wide") &gt; head(mydata) year score.A score.B score.C score.D score.E 1 1980 1.0538 1.6921 1.3165 1.7434 1.9687 6 1981 1.4773 1.6479 0.3135 0.6172 0.7704 11 1982 0.8748 1.3704 0.2788 1.6306 1.7237 16 1983 1.1224 1.1340 1.7684 1.3352 0.4317 21 1984 1.5496 1.8706 1.4641 0.5313 0.8590 26 1985 1.7715 1.8953 0.6230 0.3580 1.6313 </code></pre> <p>Now, I would like to create a new variable "period" that is 1 if the score of the subsequent year is +/- 0.5 different from the score of the previous year and that is 0 if this is not true. I would like to do so for all 5 countries. And it would be great if it were possible to identify the country-years for which period = 1 and display this information in a table.</p> <pre><code>&gt; head(mydata) year score.A score.B score.C score.D score.E period.A period.B ... 1 1980 1.0538 1.6921 1.3165 1.7434 1.9687 NA NA 6 1981 1.4773 1.6479 0.3135 0.6172 0.7704 0 .... 11 1982 0.8748 1.3704 0.2788 1.6306 1.7237 1 16 1983 1.1224 1.1340 1.7684 1.3352 0.4317 0 21 1984 1.5496 1.8706 1.4641 0.5313 0.8590 0 26 1985 1.7715 1.8953 0.6230 0.3580 1.6313 0 </code></pre> <p>I very much hope that this is not too much to ask. I tried it with <code>dist</code> in the <code>library(proxy)</code> but I do not know how to restrict the function to pairs of observation rather than the full row. Thanks a million!!</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USTiF
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to get the difference in value between subsequent observations (country-years)?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to get the difference in value between subsequent observations (country-years)?
      1. USPatrick Hausmann
      1. VTFavorite
    3. VO
      singulars
      1. POHow to get the difference in value between subsequent observations (country-years)?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COJust a quick note that you should switch to using `reshape2` since `reshape` is now deprecated and not in development.
      singulars
      1. POHow to get the difference in value between subsequent observations (country-years)?
      1. USMaiasaura
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload