Can anyone tell me, whether we can convert data frame to list in SparkR. I am aware that collect() function helps you do that. However, it is not advisable when we use large amount of data. In python/Scala, there is a function called local Iterator() which will convert the data frame to list. Am struggling with that in SparkR. Can anybody help!
Unfortunatelly collect() is the best method to do this. You can also try: saveAsTextFile but in that case you probably will not obtain whole data.
Related
My data is massive and I was wondering if there is a way I could tell R to convert each column to data types which are less memory demanding without any loss of information.
In Stata, there is a function called compress that does that. I was wondering if there is something similar in R.
I would also be grateful if you have other simple advice of how to handle large datasets in R (in addition to using data.table instead of dplyr).
I was wondering if someone knows if there's an easy and smart way to revert a matrix (that was generated by calling "model.matrix" on a data frame) back into a data.frame? The reason being that I am using the matrix in a function where the original data frame is not in the scope and I want to try something with the data frame without modifying the whole code (before I know if what I'm trying is even useful 🙂).
Thanks in advance!
Cannot run an ICC analysis in R
I have loaded my data from excel spreadsheet and have tried the following:
ICC(CMI)
I have removed my row names. I am not sure if I need to convert my columns or use a difference approach. I have loaded the Psych package.
This is my code: ICC(Test)
This is what comes back:
Error in stack.data.frame(x) : no vector columns were selected
Not sure of what this means or how to fix this? Thanks in advance for any help. I really appreciate it.
I had the same problem with a dataset. I suggest you try:
ICC(as.matrix(Test))
. This worked for me. Otherwise, type help(ICC) and check the example and compare the procedure used there compared to your data.
Good luck!
I am a beginner in R. I tried to apply aggregate function to state.x77 dataset.
aggregate(state.x77,list(Region=state.region),mean)
aggregate(state.x77,list(Region=state.region,Cold=state.x77[,"Frost"]>130),mean)
I fail to see what the function does to the dataset since I don't know much information about the dataset. I have applied str() and summary() functions but to no avail. Please do someone shed light on it.
To get information about state.x77 tpye ?state.x77 into your console.
I am trying to learn a package in R, and one example required me to use the reshape function. I know the "varying" parameter in reshape is the vector/list of variable names. But the example shows reshape(...varying=list(2)) - what does this exactly do? list(2) doesn't really give any info?