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A = A + B

in lieu of:

DO J=1,M DO I=1,NA(I,J) = A(I,J) + B(I,J) END DOEND DO

Naturally, when you want to combine two arrays in an operation, their shapes have to be compatible. Adding a seven-element vector to an eight-element vector doesn't make sense. Neither would multiplying a 2×4 array by a 3×4 array. When the two arrays have compatible shapes, relative to the operation being performed upon them, we say they are in shape conformance , as in the following code:

DOUBLE PRECISION A(8), B(8) ...A = A + B

Scalars are always considered to be in shape conformance with arrays (and other scalars). In a binary operation with an array, a scalar is treated as an array of the same size with a single element duplicated throughout.

Still, we are limited. When you reference a particular array, A, for example, you reference the whole thing, from the first element to the last. You can imagine cases where you might be interested in specifying a subset of an array. This could be either a group of consecutive elements or something like "every eighth element" (i.e., a non-unit stride through the array). Parts of arrays, possibly noncontiguous, are called array sections .

FORTRAN 90 array sections can be specified by replacing traditional subscripts with triplets of the form a:b:c , meaning "elements a through b , taken with an increment of c ." You can omit parts of the triplet, provided the meaning remains clear. For example, a:b means "elements a through b ;" a: means "elements from a to the upper bound with an increment of 1." Remember that a triplet replaces a single subscript, so an n -dimension array can have n triplets.

You can use triplets in expressions, again making sure that the parts of the expression are in conformance. Consider these statements:

REAL X(10,10), Y(100) ...X(10,1:10) = Y(91:100) X(10,:) = Y(91:100)

The first statement above assigns the last 10 elements of Y to the 10th row of X . The second statement expresses the same thing slightly differently. The lone " : " tells the compiler that the whole range (1 through 10) is implied.

Fortran 90 intrinsics

FORTRAN 90 extends the functionality of FORTRAN 77 intrinsics, and adds many new ones as well, including some intrinsic subroutines. Most can be array-valued : they can return arrays sections or scalars, depending on how they are invoked. For example, here's a new, array-valued use of the SIN intrinsic:

REAL A(100,10,2) ...A = SIN(A)

Each element of array A is replaced with its sine. FORTRAN 90 intrinsics work with array sections too, as long as the variable receiving the result is in shape conformance with the one passed:

REAL A(100,10,2) REAL B(10,10,100)... B(:,:,1) = COS(A(1:100:10,:,1))

Other intrinsics, such as SQRT , LOG , etc., have been extended as well. Among the new intrinsics are:

  • FORTRAN 90 has vector reductions such as MAXVAL , MINVAL , and SUM . For higher-order arrays (anything more than a vector) these functions can perform a reduction along a particular dimension. Additionally, there is a DOT_PRODUCT function for the vectors.
  • Intrinsics MATMUL and TRANSPOSE can manipulate whole matrices.
  • RESHAPE allows you to create a new array from elements of an old one with a different shape. SPREAD replicates an array along a new dimension. MERGE copies portions of one array into another under control of a mask. CSHIFT allows an array to be shifted in one or more dimensions.
  • SHAPE , SIZE , LBOUND , and UBOUND let you ask questions about how an array is constructed.
  • Two other new reduction intrinsics, ANY and ALL , are for testing many array elements in parallel.

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..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
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.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
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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