[R] Extensively slowing for(i in 1:400) statement
Tuomas.Kallunki at sofi.fi
Mon Jan 13 09:20:03 CET 2003
Here is what I have tried to do:
1. I have 400 time series
2. pull one serie at a time from ODBC
3. calculate some descriptives and regressions (about 50 statistic per
4. store the results in the data frame
The time consumed in each loop seems to grow linearly. I used the date()
function for timing each loop and time spent in loop seems to grow at the
speed of 0.6 * i (seconds), which implies that the last loop takes 245
seconds (first loop: 5 seconds). For the first 40 loop the ODBC down load
took 0-1 seconds, so I don't belive that ODBC connection is the problem. I
am running it in a computer with AMD 800Mhz/512 000 KB which should be
enough capacity. For example simple for(i in 1:100 000) statement runs very
smoothly? I will probably have to do several runs and I don't have the time
to wait half a day per run.
Can anyone tell what is the problem?
Is it hardware related?
Can the for() statement too long?
Do I have use rm() statement after each object becomes useless?
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