Recent content by natski

As stated in my subject line, I know that P(A|B) = P(A) and P(B|A) = P(B), i.e. A and B are separable as P(A,B) = P(A) P(B). I strongly suspect that this holds with a conditional added, but I can't find a way to formally prove it... can anyone prove this in a couple of lines via Bayes' rules...

By looping the inner code and re-running I notice in Activity Monitor that four parallel versions of the code are in fact running. So this seems simply something wrong with the rank being returned by MPI_COMM_RANK - is this a normal issue for Macs?

Hi all, I have been running mpi fortran code on Linux based systems without any trouble for some time but making the same code run on a Mac is causing me some headaches. I installed mpi using the guide at: http://www.macresearch.org/compiling-mpi-f90-support-snow-leopard I am trying to run...

Hi all, I bought my first server recently preinstalled with Ubuntu 11.04 Server. To my surprise, there was no GUI so I installed a GUI using sudo apt-get install ubuntu-desktop After startup, I get a login screen with options 'default user', 'other user' and 'guest'. When I click default user...

Hi all, Given... a + b > p b > q Is there no way to place any limits on a in terms of p and q only? I know that one is allowed to add inequalities together but not subtract, but is there any other tricks one can play to solve this? Thanks, Natski

Hi all, I have never had a server OS before but just got myself a new mac mini server with Lion server installed. The point of this was so I could ssh my machine from work and access my files from wherever I am. Sadly, I seem to be only able to ssh my machine when I am on the same wireless...

Great, thanks for the help is visualizing that!

Hi all, I have more or less convinced myself through trial and error that the following three-dimensional non-linear simultaneous equation cannot be solved. However, it would be great if someone could provide me with a proper mathematical reason as to why this is not solvable, rather than me...

I don't see how you can do this without using arrays. So you have... atable=Table[1+(i-1)*0.5,{i,1,3}]; ytable=Table[Extract[atable,i]^2-5,{i,1,Length[atable]}];

I know it is not optimal but I would suggest writing a shell script to split the data up into unique files and import each file separately.

Hi all, I am having difficulty compiling the following code in g95, which is supposed to handle coarrays... The code is: ! PROGRAM test implicit none INTEGER :: a INTEGER :: m, i IF ( THIS_IMAGE() == 1 ) THEN READ(*,*) m DO i = 1,NUM_IMAGES() a[i] = m END DO END...

Anyone aware of a multi-socket motherboard based upon the LGA-1155 socket, i.e. the new Sandy Bridge processors? I cannot find anything! Natski

What is TBB? I am guessing then coarray implementations of Fortran would run even faster than MPI on a cluster?

I see your point about the RAM constraints but if each task requires ~1Gb then actually it shouldn't be an issue for a moderately upgraded mini. Also, from an economic point of view, the mini case is quite strong... let us say our requirement is 12 cores, for the mac mini cluster... 6 x Mac...

Thank-you for everyone's help. The GPU idea sounds interesting but I need some decent clock speeds (say > 2 Ghz at least) along with multi-cores. Can GPUs really deliver high clock speeds in practice? The tasks I will be running are typically a few dozen independent number crunching tasks...