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La versión previa del estandar de FORTRAN liberada por ANSI (el American National Standard Institute), FORTRAN 77 (X3.9-1978) se escribió para promover la portabilidad de los programas FORTRAN entre plataformas distintas. No se inventaron nuevos componentes del lenguaje, más bien se incorporaron buenas características que ya estaban disponibles en compiladores en ambientes de producción. Al contrario que FORTRAN 77, el FORTRAN 90 (ANSI X3.198-1992) añade nuevas extensiones y características al lenguaje. Algunas de ellas sólo ponen al día a FORTRAN respecto a lenguajes como C (asignación dinámica de memoria, reglas de alcance) y C++ (interfaces de funciones con genericidad). Pero algunas de estas nuevas características son únicas de FORTRAN (operaciones sobre arreglos). Es interesante notar que mientras se desarrollaba la especificación de FORTRAN 90, las arquitecturas de cómputo de alto rendimiento dominantes eran los sistemas SIMD escalables como la Connection Machine, así como los sistemas de procesadores vectoriales paralelos de compañías como Cray Research.

FORTRAN 90 hace un trabajo sorprendentemente bueno en cubrir las necesidades de estas arquitecturas tan diferentes. Sus características también se adaptan razonablemente bien a los nuevos multiprocesadores con memoria compartida uniforme. Sin embargo, como veremos después, FORTRAN 90 por sí solo todavía no es suficiente para cumplir las necesidades de los sistemas distribuidos escalables con acceso a memoria no uniforme, que se están volviendo dominantes en la computación de extremo superior.

Las extensiones de FORTRAN 90 a FORTRAN 77 incluyen:

  • Constructos para arreglos
  • Asignación dinámica de memoria y variables automáticas
  • Apuntadores
  • Nuevos tipos de datos, estructuras
  • Nuevas funciones intrínsecas, incluyendo muchas que operan sobre vectores y matrices
  • Nuevas estructuras de control, tales como la sentencia WHERE
  • Interfaces de procedimientos mejoradas

Constructos para arreglos en fortran 90

Con los constructos para arreglos de FORTRAN 90, puede usted especificar arreglos completos o secciones de los mismos como participantes en operaciones unarias y binarias. Tales constructos son una característica clave para "deserializar" las aplicaciones, de forma que puedan adaptarse mejor a computadoras vectoriales o procesadores paralelos. Por ejemplo, digamos que desea usted sumar dos vectores A y B. En FORTRAN 90, puede expresarlo como una simple operación de suma, en vez de usando el bucle tradicional. Esto es, puede usted escribir:


A = A + B

en vez del tradicional bucle en FORTRAN 77:


DO I=1,N A(I) = A(I) + B(I)ENDDO

Puede que el código generado por el compilador en su estación de trabajo no se vea muy diferente, pero en algunas máquinas de arquitectura paralela o en algunas estaciones de trabajo a la vuelta de la esquina, la diferencia es significativa. La versión FORTRAN 90 declara explícitamente que los cálculos pueden realizarse en cualquier orden, incluyendo todos en paralelo simultáneamente.

Questions & Answers

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Cómputo de alto rendimiento. OpenStax CNX. Sep 02, 2011 Download for free at http://cnx.org/content/col11356/1.2
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