[R] About uniroot error

[Michael Dewey]

Dear Tania

Without your dataset I am not sure but a comment below to suggest where 
to look next.

On 24/09/2018 18:37, Tania Morgado Garcia wrote:
> Thanks for your answers. I continue to learn R and now I am detained in an
> error with uniroot that I see happens to others but I can not find the
> solution. Next the code
> 
> x1 <- BAaxOrd$V1
> y1 <- BAaxOrd$V2
> x1R <- BAaxOrdRCOS$V1
> y1R <- BAaxOrdRCOS$V2
> FCOS1 <- splinefun(smooth.spline(x1,y1))
> FRCOS1 <- splinefun(smooth.spline(x1R,y1R))
> FCOS1 <- Vectorize(FCOS1)
> FRCOS1 <- Vectorize(FRCOS1)
> 
> req(input$file1)
>        tryCatch(
>        {
>          df <- read.csv(input$file1$datapath,
>                         header = input$header,
>                         sep = "\t",
>                         quote = '"')
>        },
>        error = function(e) {
>          # return a safeError if a parsing error occurs
>          stop(safeError(e))
>        }
>      )
> 
>      #if(input$disp == "head") {
>       # return(head(df))
>      #}
>      #else {
> 
>        # Determine Carbon Reserve
>        for (row in 1:nrow(df)) {
>          if(df$ts==1) {
>             prof <-
> uniroot(f=function(x){FCOS1(x1)-df$carbono},interval=c(0,20))$root
>             limsup <- prof + df$pu
>             reserva <- integrate(FRCOS1,prof,limsup)$value
>          }

Are you sure that FCOS(x1) - df$carbono returns a scalar? It looks as 
though it returns a vector to me but without your data I am not sure so 
ignore my post if it does.
> 
> The if is because there are several types of soil, but I only put one.  The
> error is
> 
> Warning in if (is.na(f.lower)) stop("f.lower = f(lower) is NA") :
>    the condition has length > 1 and only the first element will be used
> Warning in if (is.na(f.upper)) stop("f.upper = f(upper) is NA") :
>    the condition has length > 1 and only the first element will be used
> Warning: Error in uniroot: f() values at end points not of opposite sign
> 
> The file that I load with data has a single row with the values ts = 1,
> carbon = 2.04 and pu = 15 (I left only that row to be able to determine the
> origin of the error). The functions FCOS1 and FRCOS1 are monotone
> decreasing.Graphic attachment of FCOS1
> 
> I would appreciate some help in this regard
> 
> thanks a lot
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-- 
Michael
http://www.dewey.myzen.co.uk/home.html