I am trying to download 'Landsat.rar` file (included 6 Landsat bands) and unzip it directly in r, but It doesn't work as I expected. Thank you for your help!
library(raster)
ls_url<-"https://github.com/tuyenhavan/Landsat-Data/blob/LS7/Landsat.rar"
temp<-tempfile()
download.file(ls_url,temp)
unzip(temp,"tif$")
myls<-stack("tif$")
Especially if you are using Windows, it might be that you need to use the binary mode in download.file:
download.file(ls_url, temp, mode="wb")
otherwise the file gets corrupted.
Also, the URL you are using is incorrect. You used the one for the web interface. If you want to get the file itself you need to use (check the link associated with the "Download" button):
https://github.com/tuyenhavan/Landsat-Data/raw/LS7/Landsat.rar
Finally, unzip() doesn't know how to deal with rar archive files. If you created this archive yourself, use the zip format instead; or unrar the file with another program (that you could call from R using system()).
Related
I have an excel file that I want to open in R. I tried both of these commands after saving the excel file as a csv file or a text file.
read.table() or read.csv()
I think part of the problem is where the file is located. I have it saved on the desk top. What am I missing here?
Here is the R output
In file(file, "rt") :
cannot open file 'Rtrial.csv': No such file or directory
> help.search("read.csv")
> read.csv("Rtrial.csv")
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file 'Rtrial.csv': No such file or directory
> read.table("tab")
To throw out another option, why not set the working directory (preferably via a script) to the desktop using setwd('C:\John\Desktop') and then read the files just using file names
Try
f <- file.choose()
to choose the file interactively and save the name in f.
Then run read.csv on the saved filename
d <- read.csv(f)
Sound like you just have an issue with the path. Include the full path, if you use backslashes they need to be escaped: "C:\\folder\\folder\\Desktop\\file.csv" or "C:/folder/folder/Desktop/file.csv".
myfile = read.csv("C:/folder/folder/Desktop/file.csv") # or read.table()
It may also be wise to avoid spaces and symbols in your file names, though I'm fairly certain spaces are OK.
I had to combine Maiasaura and Svun answers to get it to work: using setwd and escaping all the slashes and spaces.
setwd('C:\\Users\\firstname\ lastname\\Desktop\\folder1\\folder2\\folder3')
data = read.csv("file.csv")
data
This solved the issue for me.
Here is one way to do it. It uses the ability of R to construct file paths based on the platform and hence will work on both Mac OS and Windows. Moreover, you don't need to convert your xls file to csv, as there are many R packages that will help you read xls directly (e.g. gdata package).
# get user's home directory
home = setwd(Sys.getenv("HOME"));
# construct path to file
fpath = file.path(home, "Desktop", "RTrial.xls");
# load gdata library to read xls files
library(gdata);
# read xls file
Rtrial = read.xls(fpath);
Let me know if this works.
Save as in excel will keep the file open and lock it so you can't open it. Close the excel file or you won't be able to use it in R.
Give the full path and escape backslashes read.csv("c:\\users\\JoeUser\\Desktop\\JoesData.csv")
I have experienced that this error occurs when you either move the excel file to the destination other than where your r file is located or when you move your r file to the destination other than where your excel file is located.
Good Practice:
Keep your .r and .csv files in the same directory.
open your .r file from getting into its directory instead of opening the r file from rstuio's open file option.
You also have import Dataset option at Environment Block, just click there and get your required packages installed & from next time use this option to read datasets. You will not get this error again.
I also appreciate the above provided answers.
Another way of reading Excel including the new format xlsx could be the package speedR (https://r-forge.r-project.org/projects/speedr/). It is an interactive and visual data importer. Besides importing you can filter(subset) the existing objects from the R workspace.
My issue was very simple, the working directory was not the "Source" directory that was printed when the file ran. To fix this, you can use getwd() and setwd() to get your relative links working, or just use a full path when opening the csv.
print(getwd()) # Where does the code think it is?
setwd("~/Documents") # Where do I want my code to be?
dat = read.csv("~/Documents/Data Visualization/expDataAnalysis/one/ac1_survey.csv") #just make it work!
MAC OS It happened to me as well. I simply chose from the R toolbar MISC and then chose Change Working Directory. I was able to choose the directory that the .csv file was saved in. When I went back to the command line and typed getwd() the full directory was updated and correct and the read.csv function finally worked.
I had the same problem and when I checked the properties of the file on file explorer, it shows me the next message:
"Security: This file came from another computer and might be blocked to help protect this computer"
You click on the "Unblock" button and... you can access to the file from R without any problem, just using read.csv() function and from the directory specified as your working directory, even if is not the same as the file’s directory you are accessing to.
I just had this problem and I first switched to another directory and then switched back and the problem was fixed.
this work for me, accesing data from root. use double slash to access address.
dataset = read.csv('C:\\Users\\Desktop\\Machine Learning\\Data.csv')
Kindly check whether the file name has an extension for example:
abc.csv
if so remove the .csv extension.
set wd to the folder containing the file (~)
data<-read.csv("abc.csv")
Your data has been read the data object
In my case this very problem was raised by wrong spelling, lower case 'c:' instead of upper case 'C:' in the path. I corrected spelling and problem vanished.
You can add absolute path to the file
heisenberg <- read.csv(file="C:/Users/tiago/Desktop/sample_100000.csv")
If really want to run something like
heisenberg <- read.csv(file="sample_100000.csv")
then you'll have to change the working directory to match the place the .CSV file is at. More about it here.
I have an excel file that I want to open in R. I tried both of these commands after saving the excel file as a csv file or a text file.
read.table() or read.csv()
I think part of the problem is where the file is located. I have it saved on the desk top. What am I missing here?
Here is the R output
In file(file, "rt") :
cannot open file 'Rtrial.csv': No such file or directory
> help.search("read.csv")
> read.csv("Rtrial.csv")
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
cannot open file 'Rtrial.csv': No such file or directory
> read.table("tab")
To throw out another option, why not set the working directory (preferably via a script) to the desktop using setwd('C:\John\Desktop') and then read the files just using file names
Try
f <- file.choose()
to choose the file interactively and save the name in f.
Then run read.csv on the saved filename
d <- read.csv(f)
Sound like you just have an issue with the path. Include the full path, if you use backslashes they need to be escaped: "C:\\folder\\folder\\Desktop\\file.csv" or "C:/folder/folder/Desktop/file.csv".
myfile = read.csv("C:/folder/folder/Desktop/file.csv") # or read.table()
It may also be wise to avoid spaces and symbols in your file names, though I'm fairly certain spaces are OK.
I had to combine Maiasaura and Svun answers to get it to work: using setwd and escaping all the slashes and spaces.
setwd('C:\\Users\\firstname\ lastname\\Desktop\\folder1\\folder2\\folder3')
data = read.csv("file.csv")
data
This solved the issue for me.
Here is one way to do it. It uses the ability of R to construct file paths based on the platform and hence will work on both Mac OS and Windows. Moreover, you don't need to convert your xls file to csv, as there are many R packages that will help you read xls directly (e.g. gdata package).
# get user's home directory
home = setwd(Sys.getenv("HOME"));
# construct path to file
fpath = file.path(home, "Desktop", "RTrial.xls");
# load gdata library to read xls files
library(gdata);
# read xls file
Rtrial = read.xls(fpath);
Let me know if this works.
Save as in excel will keep the file open and lock it so you can't open it. Close the excel file or you won't be able to use it in R.
Give the full path and escape backslashes read.csv("c:\\users\\JoeUser\\Desktop\\JoesData.csv")
I have experienced that this error occurs when you either move the excel file to the destination other than where your r file is located or when you move your r file to the destination other than where your excel file is located.
Good Practice:
Keep your .r and .csv files in the same directory.
open your .r file from getting into its directory instead of opening the r file from rstuio's open file option.
You also have import Dataset option at Environment Block, just click there and get your required packages installed & from next time use this option to read datasets. You will not get this error again.
I also appreciate the above provided answers.
Another way of reading Excel including the new format xlsx could be the package speedR (https://r-forge.r-project.org/projects/speedr/). It is an interactive and visual data importer. Besides importing you can filter(subset) the existing objects from the R workspace.
My issue was very simple, the working directory was not the "Source" directory that was printed when the file ran. To fix this, you can use getwd() and setwd() to get your relative links working, or just use a full path when opening the csv.
print(getwd()) # Where does the code think it is?
setwd("~/Documents") # Where do I want my code to be?
dat = read.csv("~/Documents/Data Visualization/expDataAnalysis/one/ac1_survey.csv") #just make it work!
MAC OS It happened to me as well. I simply chose from the R toolbar MISC and then chose Change Working Directory. I was able to choose the directory that the .csv file was saved in. When I went back to the command line and typed getwd() the full directory was updated and correct and the read.csv function finally worked.
I had the same problem and when I checked the properties of the file on file explorer, it shows me the next message:
"Security: This file came from another computer and might be blocked to help protect this computer"
You click on the "Unblock" button and... you can access to the file from R without any problem, just using read.csv() function and from the directory specified as your working directory, even if is not the same as the file’s directory you are accessing to.
I just had this problem and I first switched to another directory and then switched back and the problem was fixed.
this work for me, accesing data from root. use double slash to access address.
dataset = read.csv('C:\\Users\\Desktop\\Machine Learning\\Data.csv')
Kindly check whether the file name has an extension for example:
abc.csv
if so remove the .csv extension.
set wd to the folder containing the file (~)
data<-read.csv("abc.csv")
Your data has been read the data object
In my case this very problem was raised by wrong spelling, lower case 'c:' instead of upper case 'C:' in the path. I corrected spelling and problem vanished.
You can add absolute path to the file
heisenberg <- read.csv(file="C:/Users/tiago/Desktop/sample_100000.csv")
If really want to run something like
heisenberg <- read.csv(file="sample_100000.csv")
then you'll have to change the working directory to match the place the .CSV file is at. More about it here.
I am trying to run the tutorial for written exams in the exams package (http://www.r-exams.org/tutorials/exams2nops/). Everything works fine until I am about to process the scanned documents using the nops_scan function, which normally should create a zip file.
In the console it says "Creating ZIP file", but nothing happens after that. Last output:
> nops_scan(dir = "nops_scan")
Loading required namespace: png
Reading PNG files:nops_scan1.png: Trimming PNG, rotating PNG,
extracting information, done.nops_scan2.png: Trimming PNG, rotating
PNG, extracting information, done.
Creating ZIP file:
... and then nothing happens.
I have tried to run dir("nops_scan") and it confirms that no zip file has been generated and placed in this folder.
The files in the tutorial are png-files, so what the tutorials says about running pdftk and ImageMagick, should not apply. From the tutorial: "Note that if there were PDF files that need to be scanned, then the PDF toolkit pdftk and the function convert from ImageMagick need to be available outside of R on the command line."
Could the problem still be related to the above comment about pdftk or ImageMagick? (Which program is used to create the zip files?) I do not know how to make these programs "available outside of R", so instruction on this would be appreciated!
The base zip() function from the tools package is used, see ?zip. If you are on Windows maybe you need to install the Rtools? These are available from CRAN at https://CRAN.R-project.org/bin/windows/Rtools/.
PDFTk and ImageMagick are not involved in this case, they are only needed to convert PDF files to PNG which can then be processed in R. (And just in case anybody else is looking for this information: http://www.R-exams.org/tutorials/installation/ provides links to installation files for these applications.)
There is no version control at my work (we have an outdated, centralized system with sensitive patient information, so we can't save things outside of it). When I save a .RData file from a script, I would like to be able to save the exact version of that .R file with it at that time. Is there a way to do this?
E.g. if I have an R script "run_analysis.R" that has the line
save(data,file='foo.RData')
Is there a way I can do something like
save(data,run_analysis.R,file='foo.RData')
so that if I pull up the data file a year later I'll know exactly what code was used to create it?
you could zip the foo.RData file together with the run_analysis.R file and store the zipped file.
the CRAN package [zip] (https://cran.r-project.org/web/packages/zip/zip.pdf) can be used to create the zip file from within r.
I want to save my code in R. I did:
save(Data,file="Code_Data.R")
When I open the file in R again, the code looks like hieroglyphics.
How can I save the code in a way, that I can read the code in an editor or RStudio again?
save outputs a binary copy of the objects you tell it to save, not R code. Because you are naming this file with a ".R" extension, RStudio is blindly trying to open this binary file as R code, and you are seeing the results of that mess.
Technically, the R language doesn't care what the extension of the file is. As long as you know that the file contains, you can load it back in with the command load("Code_Data.R"). However, if you want to get RStudio to recognize that this is actually a file containing binary data and not R code, try saving the file with the canonical ".RData" extension:
save(Data, file="Code_Data.RData")
Using the ".RData" extension will also help you and other programmers who look at your code avoid this confusion in the future.