How can I find the mean of three rasters? - r

I have three dataframes, for which I am trying to find a cell-by-cell mean.
r1<-raster('a.tif')
r2<-raster('b.tif')
r3<-raster('c.tif')
However, doing this is giving me the following error
q<-mean(r1,r2,r3)
or
q<-(r1+r2+r3)/3
Error
Error in .local(.Object, ...) : options(warn) not set
Warning message:
closing unused connection 4 .....

That is a weird error message. Often this type of situation goes away if you restart R without loading an old workspace (which may be stale). If that is what is going on use unlink(".RData"), exit R without saving and start again.
To answer your aside question, yes it is much easier to stack them. E.g.
f <- list.files(pattern='tif$')
s <- stack(f)
x <- sum(s)

Related

Error in validityMethod(as(object, superClass)) : object 'Matrix_validate' not found

I just try to use :
scRNA <- FindNeighbors(scRNA, dims = pc.num)
and
scRNA.counts <- Read10X(data.dir = "filtered_feature_bc_matrix")
and both of them gives error like :
Error in validityMethod(as(object, superClass)) : object 'Matrix_validate' not found
I guess these code totally run well in other's computer
so I wonder what's wrong with my code and how to fix it ?
Indeed, to solve the problem for you, it should be sufficient to do what #Mikael Jagan says:
update.packages("Matrix")
2nd thought: The above may not solve the problem entirely:
As there are other packages involved, some of these may have to be re-installed (after the updating of Matrix).
Can you post the output (or good summary of that if it's too long) of
traceback()
immediately after producing the error you are seeing?

Error: object 'skim_without_charts' not found [duplicate]

I got the error message:
Error: object 'x' not found
Or a more complex version like
Error in mean(x) :
error in evaluating the argument 'x' in selecting a method for function 'mean': Error: object 'x' not found
What does this mean?
The error means that R could not find the variable mentioned in the error message.
The easiest way to reproduce the error is to type the name of a variable that doesn't exist. (If you've defined x already, use a different variable name.)
x
## Error: object 'x' not found
The more complex version of the error has the same cause: calling a function when x does not exist.
mean(x)
## Error in mean(x) :
## error in evaluating the argument 'x' in selecting a method for function 'mean': Error: object 'x' not found
Once the variable has been defined, the error will not occur.
x <- 1:5
x
## [1] 1 2 3 4 5
mean(x)
## [1] 3
You can check to see if a variable exists using ls or exists.
ls() # lists all the variables that have been defined
exists("x") # returns TRUE or FALSE, depending upon whether x has been defined.
Errors like this can occur when you are using non-standard evaluation. For example, when using subset, the error will occur if a column name is not present in the data frame to subset.
d <- data.frame(a = rnorm(5))
subset(d, b > 0)
## Error in eval(expr, envir, enclos) : object 'b' not found
The error can also occur if you use custom evaluation.
get("var", "package:stats") #returns the var function
get("var", "package:utils")
## Error in get("var", "package:utils") : object 'var' not found
In the second case, the var function cannot be found when R looks in the utils package's environment because utils is further down the search list than stats.
In more advanced use cases, you may wish to read:
The Scope section of the CRAN manual Intro to R and demo(scoping)
The Non-standard evaluation chapter of Advanced R
While executing multiple lines of code in R, you need to first select all the lines of code and then click on "Run".
This error usually comes up when we don't select our statements and click on "Run".
Let's discuss why an "object not found" error can be thrown in R in addition to explaining what it means. What it means (to many) is obvious: the variable in question, at least according to the R interpreter, has not yet been defined, but if you see your object in your code there can be multiple reasons for why this is happening:
check syntax of your declarations. If you mis-typed even one letter or used upper case instead of lower case in a later calling statement, then it won't match your original declaration and this error will occur.
Are you getting this error in a notebook or markdown document? You may simply need to re-run an earlier cell that has your declarations before running the current cell where you are calling the variable.
Are you trying to knit your R document and the variable works find when you run the cells but not when you knit the cells? If so - then you want to examine the snippet I am providing below for a possible side effect that triggers this error:
{r sourceDataProb1, echo=F, eval=F}
# some code here
The above snippet is from the beginning of an R markdown cell. If eval and echo are both set to False this can trigger an error when you try to knit the document. To clarify. I had a use case where I had left these flags as False because I thought i did not want my code echoed or its results to show in the markdown HTML I was generating. But since the variable was then used in later cells, this caused an error during knitting. Simple trial and error with T/F TRUE/FALSE flags can establish if this is the source of your error when it occurs in knitting an R markdown document from RStudio.
Lastly: did you remove the variable or clear it from memory after declaring it?
rm() removes the variable
hitting the broom icon in the evironment window of RStudio clearls everything in the current working environment
ls() can help you see what is active right now to look for a missing declaration.
exists("x") - as mentioned by another poster, can help you test a specific value in an environment with a very lengthy list of active variables
I had a similar problem with R-studio. When I tried to do my plots, this message was showing up.
Eventually I realised that the reason behind this was that my "window" for the plots was too small, and I had to make it bigger to "fit" all the plots inside!
Hope to help
I'm going to add this on here even though it's not a new question as it comes quite highly in the search results for the error:
As mentioned above, re checking syntax, if you're using dplyr, make sure you have all the %>% pipes at the end of the lines above the error, otherwise the contents of anything like a select statement won't pass down into the next part of the code block.

Is it possible to not printing error messages when knitting an RMarkdown messages? [duplicate]

I am running a simulation study in R. Occassionally, my simulation study produces an error message. As I implemented my simulation study in a function, the simulation stops when this error message occurs. I know that it is bad practice to suppress errors, but at this moment to me there is no other option than to suppress the error and then go on with the next simulation until the total number of simulations I like to run. To do this, I have to suppress the error message R produces.
To do this, I tried different things:
library(base64)
suppressWarnings
suppressMessages
options(error = expression(NULL))
In the first two options, only warnings and message are suprressed, so that's no help. If I understand it correctly, in the last case, all error messages should be avoided. However, that does not help, the function still stops with an error message.
Has someone any idea why this does not work the way I expect it to work? I searched the internet for solutions, but could only find the above mentioned ways.
In the function I am running my simulation, a part of the code is analysed by the external program JAGS (Gibbs sampler) and the error message is produced by this analysis. Might this be where it goes wrong?
Note that I do not have to supress a certain/specific error message, as there are no other error messages produced, it is 'good enough' to have an option that supresses just all error messages.
Thanks for your time and help!
As suggested by the previous solution, you can use try or tryCatch functions, which will encapsulate the error (more info in Advanced R). However, they will not suppress the error reporting message to stderr by default.
This can be achieved by setting their parameters. For try, set silent=TRUE. For tryCatch set error=function(e){}.
Examples:
o <- try(1 + "a")
> Error in 1 + "a" : non-numeric argument to binary operator
o <- try(1 + "a", silent=TRUE) # no error printed
o <- tryCatch(1 + "a")
> Error in 1 + "a" : non-numeric argument to binary operator
o <- tryCatch(1 + "a", error=function(e){})
There is a big difference between suppressing a message and suppressing the response to an error. If a function cannot complete its task, it will of necessity return an error (although some functions have a command-line argument to take some other action in case of error). What you need, as Zoonekynd suggested, is to use try or trycatch to "encapsulate" the error so that your main program flow can continue even when the function fails.

What causes this? rdplot Error in R: Error in seq.default(x_min, c, jump_l) : invalid '(to - from)/by'

I am trying to use some very simple data in rdplot but I keep getting the error: Error in seq.default(x_min, c, jump_l) : invalid '(to - from)/by' I found this response from a diffrent post on Stack Overflow but can seem to apply the fix to the rdplot function. does anyone know how can this be fixed?
The actual code I am using is:
library(rdrobust)
rdplot(y = dt$treated, x = dt$score)
Reproducibility:
Here is a sample of my data, as I've said it is fairly common data. So far I have found a couple of things:
There are multiple subsets of the observations that seem to cause problems
Changing the nbins or binselect arguments from their default will fix the problem
The first time you get an error is on the set 1:1463, however using only observations 2:1464 is OK.
The recent rdrobust version 1.0.1 should take care of this error.

Problems building an R package (NAs introduced by coercion)

I have written the Boggler package which includes a Play.Boggle() function that calls, on line 87, a progress bar script using shell:
shell(cmd = sprintf('Rscript.exe R/progress_bar.R "%i"', time.limit + 1), wait=FALSE)
Everything works fine when sourcing the files individually and then calling the main Play.Boggle() function, but when I try to check/build the package (under Win7-64 using RStudio), I get a failure message -- here's what the 00install.out reports:
** preparing package for lazy loading
Warning in eval(expr, envir, enclos) : NAs introduced by coercion
Error in time.limit:0 : NA/NaN argument
To make sure the argument "%i" (time.limit + 1) was correctly passed to the progress_bar.R, I added a cat(time.limit) to the script (commenting the rest out to make sure the package would build without any errors) and directed its output to a log file like this:
'Rscript.exe R/progress_bar.R "%i" > out.log'
Conclusion: the time limit is indeed passed along as expected. So I can't figure out why I get this "NA/NaN argument" error message. It must have something to do with lazy loading, concept that I haven't fully got my head around yet.
So my question is: what can I do to successfully check/build this package with full functionality (including progress_bar.R)?
Note: On github, the progress_bar.R script is there but all its content is commented out so that the package can successfully be installed. The shell(...) function call is still active, doing nothing but executing an empty script.
So the problem arises when trying to build or check, in which case all R scripts are executed, as pointed out by Roland. A simple workaround allows the package to check/build without any problems. The fix is just to add to the progress_bar.R the following lines after it tries to recuperate the commandargs (lines 10-11):
if(time.limit %in% c(NA, NaN))
time.limit <- 10 # or any minimal number
There's surely other ways to go about this. But this being a game programmed for fun, I'll happily go with that patch. Hopefully this can be of help to someone down the road and I won't have wasted 50 precious rep points in vain for that bounty! :D

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