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Two-dimensional distributions

This figure shows two grids of numbered boxes. Both are titled with two lines of code. The grid on the left, with code (Block, Block), has sixteen boxes, four boxes each numbered 1, 2, 3, and 4, and the numbers are organized in quadrants. The grid on the right, with code (*, block), has sixteen boxes, four boxes each numbered 1, 2, 3, and 4, and the numbers are organized in columns.

When dealing with more than one data structure to perform a computation, you can either separately distribute them or use the ALIGN directive to ensure that corresponding elements of the two data structures are to be allocated together. In the following example, we have a plate array and a scaling factor that must be applied to each column of the plate during the computation:


DIMENSION PLATE(200,200),SCALE(200) !HPF$ DISTRIBUTE PLATE(*,BLOCK)!HPF$ ALIGN SCALE(I) WITH PLATE(J,I)

Or:


DIMENSION PLATE(200,200),SCALE(200) !HPF$ DISTRIBUTE PLATE(*,BLOCK)!HPF$ ALIGN SCALE(:) WITH PLATE(*,:)

In both examples, the PLATE and the SCALE variables are allocated to the same processors as the corresponding columns of PLATE . The * and : syntax communicate the same information. When * is used, that dimension is collapsed, and it doesn't participate in the distribution. When the : is used, it means that dimension follows the corresponding dimension in the variable that has already been distributed.

You could also specify the layout of the SCALE variable and have the PLATE variable "follow" the layout of the SCALE variable:


DIMENSION PLATE(200,200),SCALE(200) !HPF$ DISTRIBUTE SCALE(BLOCK)!HPF$ ALIGN PLATE(J,I) WITH SCALE(I)

You can put simple arithmetic expressions into the ALIGN directive subject to some limitations. Other directives include:

  • PROCESSORS Allows you to create a shape of the processor configuration that can be used to align other data structures.
  • REDISTRIBUTE and REALIGN Allow you to dynamically reshape data structures at runtime as the communication patterns change during the course of the run.
  • TEMPLATE Allows you to create an array that uses no space. Instead of distributing one data structure and aligning all the other data structures, some users will create and distribute a template and then align all of the real data structures to that template.

The use of directives can range from very simple to very complex. In some situations, you distribute the one large shared structure, align a few related structures and you are done. In other situations, programmers attempt to optimize communications based on the topology of the interconnection network (hypercube, multi-stage interconnection network, mesh, or toroid) using very detailed directives. They also might carefully redistribute the data at the various phases of the computation.

Hopefully your application will yield good performance without too much effort.

Hpf control structures

While the HPF designers were in the midst of defining a new language, they set about improving on what they saw as limitations in FORTRAN 90. Interestingly, these modifications are what is being considered as part of the new FORTRAN 95 standard.

The FORALL statement allows the user to express simple iterative operations that apply to the entire array without resorting to a do-loop (remember, do-loops force order). For example:


FORALL (I=1:100, J=1:100) A(I,J) = I + J

This can be expressed in native FORTRAN 90 but it is rather ugly, counterintuitive, and prone to error.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, High performance computing. OpenStax CNX. Aug 25, 2010 Download for free at http://cnx.org/content/col11136/1.5
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