Matlab for Beginners

urnash · Post by **urnash** » Wed Jun 16, 2010 8:57 am

I know it's a small threadjack but: earlier in this thread we discussed the speed of R vs Matlab. I've just found http://www.cybaea.net/Blogs/Data/Faster-R-through-better-BLAS.html which describes different ways of speeding up R. Hope this helps someone...

Maggette · Post by **Maggette** » Tue Jul 06, 2010 4:05 pm

Actually I don't really need it right now, but thanks for the link. This sounds interesting and is good to know it exists. Thanks

Praetorian · Post by **Praetorian** » Wed Jul 07, 2010 10:04 am

Another note on R Performance: For Intel Machines the fastest solution is to link against Intel MKL. Revolution R gives you optimized Builds out of the box under windows. For Linux Users a Revolution version is available for Ubuntu (but only R2.9.2). A general installation tutorial for Linux can be found at: http://psyccomputing.blogspot.com/2010/04/compiling-64-bit-r-2101-with-mkl-in.html - i used that to speed up my Amazon Cloud Environment.

taa · Post by **taa** » Wed Sep 26, 2012 9:19 pm

Hi all

I need a (1xN) vector of dates in the following format "yyyymmdd" (i.e. 19960101) for a for-loop.

start_date = datenum('01-Jan-1996');

end_date = datenum('31-Dec-2012');

date = datevec(start_date:1:end_date);

How should I proceed?

Thx for your help!!

djfostner · Post by **djfostner** » Wed Sep 26, 2012 9:53 pm

If you're looking to get the data into a vector of formatted strings you could use the built-in datestr command.

dateString = datestr(date,'yyyymmdd');

Hope that helps.

taa · Post by **taa** » Wed Sep 26, 2012 10:00 pm

Thx for that, djfostner.

Unfortunately, I had this before and I dont know how to access/use the first, second etc. value in dateString.

Afterwards I would like to use sprintf in a for-loop to combine a hyperlink with the date in the above mentioned vector.

Thx again

silverside · Post by **silverside** » Wed Sep 26, 2012 10:10 pm

in approximate order of complexity (and reverse order of speed):

use a for loop with datestr()

or

use cellfun()

or

use a custom-written loop using preallocated strings for numbers from 1 to 12, 1 to 31, and 0 to 99. date-related functions in matlab are notoriously slow.

tabris · Post by **tabris** » Fri Dec 14, 2012 5:22 pm

Ok this might be a real basic question but I am unsure of how to do this.

I would like to set my machine timezone from matlab to another timezone whilst running a script in matlab and then convert it back. How would I do this actually or is this possible?

tristanreid · Post by **tristanreid** » Fri Dec 14, 2012 6:49 pm

I can give you a script that will do this, but may I ask: is this for string formatting purposes? There may be better alternatives. If for no other reason, you're going to mess up your calendar if you keep switching back and forth - any invite that gets received during this time has high probability of getting jacked.

Here's a Matlab example of converting local to UTC, although you're going to need Java installed for this to run (and CLASSPATH set in Matlab)

http://www.mathworks.com/matlabcentral/fileexchange/22295-localtimetoutc/content/local_time_to_utc.m

tabris · Post by **tabris** » Sat Dec 15, 2012 4:10 am

Thanks! And no it is not for date formating, I actually have to call an executable file that requires my timezone as an input and I cannot recompile this file since I do not have the source code.

Don't worry I do not have many invites so this patch work will do!