how to use data.frame/object outside function in Rstudio

[ahmedshingaly]

Greeting all,
I was wondering how can I call a data.frame or an object outside a function class? i tried to use <<- but with no use.

simply put
I have a function

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui

A= Q1+2
B=Q2+A
long= 37.6543
lat= 127.5432
C <<- data.frame(A,B, lat, long)

return (list(C))
}

#later I want to use C values to add markers inside leaflet but I cannot call C data.frame outside the function class. it gives me an error of [there is no object called "C"]

# I want to call C dataframe outside the function here and use it for leaflet marker values as following

data <- C #C is the dataframe from the mod0 function
data <-data[complete.cases(data),] #remove empty cell data

data$long <- as.numeric(data$long) #to make sure this is a numeric column not text
data$lat <- as.numeric(data$lat)
data$results <- as.numeric(data$results)

thank you in advance for any reply and advises

best regards
Ahmed Ali
PhD Candidate
Chung Ang University

[FJCC]

If you return C as the value of the function, you can use it elsewhere.

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui
  
  A= Q1+2
  B=Q2+A
  long= 37.6543
  lat= 127.5432
  C <- data.frame(A,B, lat, long)
  
  return (C)
}

DF <- mod0(1,2)
DF
#>   A B      lat    long
#> 1 3 5 127.5432 37.6543

^{Created on 2019-10-17 by the reprex package (v0.3.0.9000)}

[ahmedshingaly]

@FJCC

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui A= Q1+2 B=Q2+A long= 37.6543 lat= 127.5432 C <- data.frame(A,B, lat, long) return (C) }

thanks alot FJCC for the quick reply and great solution, I really appreciate your time spent responding to our concerns.

I have another question
is it possible to have more than one dataframe output from the function class
for example:

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui

A= Q1+2
B=Q2+A
long= 37.6543
lat= 127.5432
C <- data.frame(A,B, lat, long)
D<- data.frame(A,lat)
return (list(D,C))
}

then how can I call dataframe C and dataframe D separately

DF1<- C
DF2<- D

thanks in advance
Ahmed Ali

[FJCC]

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui
  
  A= Q1+2
  B=Q2+A
  long= 37.6543
  lat= 127.5432
  C <- data.frame(A,B, lat, long)
  D<- data.frame(A,lat)
  return (list(C, D))
}

ListOfDF <- mod0(1,2)
ListOfDF
#> [[1]]
#>   A B      lat    long
#> 1 3 5 127.5432 37.6543
#> 
#> [[2]]
#>   A      lat
#> 1 3 127.5432

DF1 <- ListOfDF[[1]]

DF2 <- ListOfDF[[2]]

DF1
#>   A B      lat    long
#> 1 3 5 127.5432 37.6543

DF2
#>   A      lat
#> 1 3 127.5432

^{Created on 2019-10-17 by the reprex package (v0.3.0.9000)}

[ahmedshingaly]

@FJCC

mod0 = function(Q1,Q2){ #where Q1 and Q2 are numeric input in the shiny app ui A= Q1+2 B=Q2+A long= 37.6543 lat= 127.5432 C <- data.frame(A,B, lat, long) D<- data.frame(A,lat) return (list(C, D)) } ListOfDF <- mod0(1,2)

thanks alot FJCC,
that really solved a lot of problems for me,
I used to repeat copy/paste the whole Function to return a different dataset with mod0 , mod1, ..
now with your guided example I can get multiple outputs from the same function. thanks alot and have a blessed weekend.

Ahmed Ali