You may go to use a data file in Stata and get the error…
no room to add more observations r(901);
Stata is probably telling you that Stata has not allocated enough memory to read the data file. You can check to see how much memory is allocated to hold your data using the memory command. I am running Stata under Windows, and this is what the memory command told me.
memory
Total memory 1,024,000 bytes 100.00%
overhead (pointers) 0 0.00%
data 0 0.00%
------------
data + overhead 0 0.00%
programs, saved results, etc. 368 0.04%
------------
Total 368 0.04%
Free 1,023,632 99.96%
This tells me that I have a little bit under 1 megabyte free for reading in a data file. I have a data file called bigfile.dta that I want to read that is about 1.7 megabytes, so that is why I was getting the no room to add more observations error. I will allocate 5 megabytes of memory with the set memory command below, and then try using my file.
set memory 5m (5120k) use bigfile
Now that I have allocated enough memory, I am able to read the file. If you want to allocate 5m (five megabytes) every time I start Stata, you can type
set memory 5m, permanently
And then Stata will allocate this amount of memory every time you start Stata.
If you routinely use very large datasets then you might want to consider setting the memory allocated to Stata to be a much larger value, say…
set memory 100m, permanently
You can permanently set the memory to any value that you require and that your computer can manage. It is also possible to set the permanent memory size from the Stata preferences page for your system.