Bias correcting one station

[cyndyfem]

Hi, I have an extracted gridded data for one station. I want to bias correct the extracted station using an observed data. I used the biasCorrection1D command but it did not work. I am not trying to bias-correct the grids but only bias- correcting and extracted grid data. Is there an option to do this in downscaleR since it seems the function biasCorrection1D does not seem to work anymore. Thanks!

[cyndyfem]

In addition, when I tried using the biasCorrection function, I got the error

Error in if (nrow(aux.ind)) if (!is.matrix(coords)) { : argument is of length zero

[miturbide]

Hi @cyndyfem, Could you please post the result of applying function str() to your data?

[cyndyfem]

HI @miturbide please, see the results below

str(x) 'data.frame': 9855 obs. of 14 variables: $ X65046: num 0 0 0 0 0 0 0 0 0 0 ... $ X65064: num 0 0 0 0 0 0 0 0 0 0 ... $ X65055: num 0 0 0 0 0 0 0 0 0 0 ... $ X65134: num 0 0 0 0 0 0 0 0 0 0 ... $ X61085: num 0 0 0 0 0 0 0 0 0 0 ... $ X61045: num 0 0 0 0 0 0 0 0 0 0 ... $ X61090: num 0 0 0 0 0 0 0 0 0 0 ... $ X61091: num 0 0 0 0 0 0 0 0 0 0 ... $ X61096: num 0 0 0 0 0 0 0 0 0 0 ... $ X65073: num 0 0 0 0 0 0 0 0 0 0 ... $ X65028: num 0 0 0 0 0 0 0 0 0 0 ... $ X65019: num 0 0 0 0 0 0 0 0 0 0 ... $ X65075: num 0 0 0 0 0 0 0 0 0 0 ... $ X65082: num 0 0 0 0 0 0 0 0 0 0 ...

str(y) 'data.frame': 9855 obs. of 14 variables: $ X65046: num 0 0 0 0 0 0 0 0 0 0 ... $ X65064: num 0 0 0 0 0 0 0 0 0 0 ... $ X65055: num 0 0 0 0 0 0 0 0 0 0 ... $ X65134: num 0 0 0 0 0 0 0 0 0 0 ... $ X61085: num 0 0 0 0 0 0 0 0 0 0 ... $ X61045: num 0 0 0 0 0 0 0 0 0 0 ... $ X61090: num 0 0 0 0 0 0 0 0 0 0 ... $ X61091: num 0 0 0 0 0 0 0 0 0 0 ... $ X61096: num 0 0 0 0 0 0 0 0 0 0 ... $ X65073: num 0 0 0 0 0 0 0 0 0 0 ... $ X65028: num 0 0 0 0 0 0 0 0 0 0 ... $ X65019: num 0 0 0 0 0 0 0 0 0 0 ... $ X65075: num 0 0 0 0 0 0 0 0 0 0 ... $ X65082: num 0 0 0 0 0 0 0 0 0 0 ...

[miturbide]

Is these data for a single station or for 14 stations? If the case is the latter, you could apply biasCorrection1D for each of the columns in your data in a loop (your data is 2D). Please note that function biasCorrection only works with "climate4R grids": https://github.com/SantanderMetGroup/loadeR/wiki

[cyndyfem]

@miturbide thanks for your reply. Yes, the situation is for the later. Okay, I would like to give an example for just a single station.

e.g

Sys.setenv(JAVA_HOME='C:\Program Files\Java\jdk1.7.0_80\jre') library(downscaleR) library(loadeR)

This worked perfectly and the packages were loaded

x<-read.csv("prc.txt",header=TRUE) x<-data.frame(x[,1]) y<-read.csv("D:/Cordex/Hist/Historical/prc.txt",header=TRUE) y<-data.frame(y[,1])

BC <- biasCorrection1D(o=x, p = y,s = y,precip = TRUE,method = "eqm", extrapolation = "constant",pr.threshold = 0.1)

Now the error

Error in biasCorrection1D(o = x, p = y, s = y, precip = TRUE, method = "eqm", : could not find function "biasCorrection1D"

I have successfully used the biasCorrection function with climate4R grids, but the biasCorrection1D function is not working for my new experiment.

[miturbide]

biasCorrection1D is an internal function. Internal functions in R need to be called in this form: package:::function()

As described in the help documentation, in downscaleR, internal functions for bias correction work with vectors (1D data). A data.frame is a 2D object, thus, when you run e.g. y <- data.frame(y[,1]) you are creating a 2D object, you should simply use y <- y[,1].

I recommend you to use the internal function eqm for this specific case, otherwise (using biasCorrection1D) you have to set parameters for other methods. For instance:

data("EOBS_Iberia_pr")
data("CORDEX_Iberia_pr")
y <- VALUE_Iberia_pr$Data[,1]
x <- CORDEX_Iberia_pr$Data[, 4, 7]
class(x) # numeric
class(y) # numeric
eqm1 <- downscaleR:::eqm(o =  y, p = x, s = x,
                        precip = TRUE,
                        pr.threshold = 1,
                        extrapolation = "constant",
                        n.quantiles = 100)

[cyndyfem]

ok. Thank you. It worked