[R] Get data from a list of data frames

[Gerrit Eichner]

Hello, Stefano,

maybe the following example contains what you want to achieve:

Station1 <- data.frame(sensor = c("thermometer", "raingauge", 
"snowgauge", "anemometer"),
                        code = c(2583, 1478, 3178, NA))
Station2 <- data.frame(sensor = c("thermometer", "raingauge", 
"snowgauge", "anemometer"),
                        code = c(2584, 1479, 3179, 4453))
Station3 <- data.frame(sensor = c("thermometer", "raingauge", 
"snowgauge", "anemometer"),
                        code = c(2584, 1479, 3179, 4453))
Station4 <- data.frame(sensor = rev(c("thermometer", "raingauge", 
"snowgauge", "anemometer")),
                        code = c(2584, 1479, 3179, 4453))
Station5 <- data.frame(sensor = c("raingauge", "snowgauge", 
"thermometer", "anemometer"),
                        code = c(2584, 1479, 3179, 4453))

Total <- list("Station1"=Station1, "Station2"=Station2,
               Station3 = Station3, Station4 = Station4,
               Station5 = Station5)

select.stat <- paste0("Station", c(1, 4, 5))
select.sens <- "thermometer"

sapply(Total[select.stat], function(x, sens)
   x$code[x$sensor == sens], sens = select.sens)



  Hth --  Gerrit

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Dr. Gerrit Eichner                   Mathematical Institute, Room 212
gerrit.eichner using math.uni-giessen.de   Justus-Liebig-University Giessen
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Am 15.12.2022 um 14:52 schrieb Stefano Sofia:
> Dear R-list users,
> 
> I have a list of n data frames built as follows:
> 
> 
> Station1 <- data.frame(sensor = c("thermometer", "raingauge", "snowgauge", "anemometer"), code = c(2583, 1478, 3178, NA))
> Station2 <- data.frame(sensor = c("thermometer", "raingauge", "snowgauge", "anemometer"), code = c(2584, 1479, 3179, 4453))
> ....
> 
> Total <- list("Station1"=Station1, "Station2"=Station2, ...)
> 
> I would need to have a vector with the sensor codes of the thermometers of some stations, let's say of Station1, Station2 and Station5 (i.e. c(2583, 2584, 2587)).
> I tried with lapply, but I have not been able to get what I need.
> Could you please help me?
> 
> Thank you
> 
> Stefano
> 
> 
> 
>           (oo)
> --oOO--( )--OOo--------------------------------------
> Stefano Sofia PhD
> Civil Protection - Marche Region - Italy
> Meteo Section
> Snow Section
> Via del Colle Ameno 5
> 60126 Torrette di Ancona, Ancona (AN)
> Uff: +39 071 806 7743
> E-mail: stefano.sofia using regione.marche.it
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