Fortran 95!!!!

kathrynag

Does anyone know how to program with Fortan 95? I need some help!

mgb_phys

Something specific to F95 or a general intro to Fortran 90?

http://www.cisl.ucar.edu/tcg/consweb.../tutorial.html

kathrynag

Something specific:
I'm trying to write a program in Fortan 95. I need to find the distance between 2 points (x1,y1) and (x2,y2) on a Cartesian coordinate plane given by the equation:
d=sqrt[(x1-x2)^2+(y1-y2)^2].
I want to use the points (-1,1) and (6,2).

This is the copy of what I am doing:
program distance
!kathryn, Assignment 2-21, calculate distance between two points.
implicit none
real::x1 !This is the x from the first ordered pair.
real::y1 !This is the y from the first ordered pair.
real::x2 !This is the x from the second ordered pair.
real::y2 !This is the y from the second ordered pair.
real:: d !This is the distance we are trying to find.
write(*,*) 'This program calculates the distance between two points
+ on a Cartesian coordinate plane.'
read(*,*) d
d=sqrt((x1-x2)^2+(y1-y2)^2) !Calculation
read(*,*) 'The distance between any two points ,'(x1,y1)', and ,'(x2,y2)', is ,'d
end


My problem is that when I compile, I get errors. Where am I going wrong?

mgb_phys

I don't know f90 but what are the error messages ?

kathrynag

i don't know right off hand, but it's f95.

mgb_phys

Theres no real difference, between Fortran90 and Fortran95,
The compiler error should at least tell you which line the problem is on.

Is ^ a new operator in f95 It used to be '**' in f77 ?

kathrynag

Ok, well I could try it again. I can't run it on my comp. I'll have to try a different one.

Useful nucleus

I think there are two bugs:

(1) The exponentiation operator is (**) in F95, not (^)
(2)The read statement before end program should be write instead

kathrynag

Ok, I'll try those, but I still got errors. Is the last read statement fine other than the write?

Useful nucleus

Hi kathrynag

It looks like that there are some synatax errors and a logical one actually.

(1) In your code you wrote

The continuation operator in Fortran is "&" not "+", so a valid statement is
(2) A logical error in this statement:

You are supposed to ask the user to enter the coordinates x1,x2,y1,y2 , not the distance . After all your code should calculate the distance when the user enters the coordinates. So a valid statement should be


(3) This statment has some syntax erros:
A better one is :
Compare them.

(4) Finally, if you are using fixed format file, make sure that none of the lines is longer than 80 columns. If any is longer, use the continuation operator "&"

Hope that works for you

kathrynag

Ok, I'll try those and let you know what happens.
should I do read(*,*) x1,x2,y1,y2 or seperate lines for each variable?

Useful nucleus

It is fine as you wrote it.

kathrynag

I got it all figured out except for the extension of a line. It works fine if I don't extend a line.