fork(2) download
copy 
  1. program TraceExponential                                  
  2. !-----------------------------------------------------------------------
  3. !Christina Urbanczyk             Lab5               February 16, 2010   
  4. ! This algorithm uses a factorial subprogram to calculate the &         
  5. ! approximate value of exp(x) using the infinite series.                
  6. !    Variables used are:                                                
  7. !    count: DO-loop control variable                                    
  8. !    FactorialNum: function subprogram to calculate factorials          
  9. !    X: User determined value to find infinite series of                
  10. !    Numits:Number of iterations                                        
  11. !    Countits: Count iterations                                         
  12. !    Tol:Convergence criteria                                           
  13. !    Esum:Sum of Exp(x)                                                 
  14. !    Number:Subprogram variable                                         
  15. !    FactorialNum:Factorial of integer                                  
  16. !                                                                       
  17. ! Input:X,Tol,Numits                                                    
  18. ! Output:FactorialNum                                                   
  19. !-----------------------------------------------------------------------
  20.  
  21. IMPLICIT NONE
  22. integer,parameter::dp=selected_real_kind(15) !15 significant figures 
  23. integer:: count, Numits,Countits                             
  24. real(dp)::X, Esum, Tol                                               
  25. character (len=1):: Method                                           
  26.  
  27. Esum=1
  28.  
  29. write(*,*) "Please enter a value that you would like to find the infinite series of:"
  30. read(*,*) X
  31.  
  32. write(*,*) "Would you like to define the number of iterations (Y or N)?"
  33.    read (*,*) Method
  34.  IF (Method == "Y" .OR. Method== "y") THEN
  35.    write (*,*) "What is your number of iterations?"
  36.    read (*,*) Numits
  37.  
  38. !Display Trace Table
  39. write (*,'(T1,A7,T20,A9,T43,A8,T58,A5,T73,A6/)') "Count","X^count","Count!","Esum","Exp(X)"
  40.       DO count=1,Numits
  41.           Esum= Esum+(x**count)/(real(FactorialNum(Count)))
  42.        write(*,'(T1,I2,T7,F20.1,T30,F20.1,T51,F15.5,T67,F15.5)') count,X**count,FactorialNum(Count),Esum, exp(X)
  43.       END DO
  44.         write(*,*) "Given",Numits,"iterations, the estimated value is",Esum,"."
  45.         write(*,*) "The estimated value had",abs(exp(X)-Esum)/exp(X)*100.0,"% error from the actual value of",exp(x)
  46.    ELSE IF  (Method == "N" .OR. Method == "n") THEN
  47.         write (*,*) "What is your convergence criteria?"
  48.         read (*,*) Tol
  49.  
  50. !Display Trace Table
  51. write (*,'(T1,A7,T20,A9,T40,A8,T58,A5,T73,A6/)') "Count","X^count","Count!","Esum","Exp(X)"
  52.       DO count=1,Countits
  53.       Esum= Esum+(x**count)/(real(FactorialNum(Count)))
  54.       write(*,'(T1,I2,T7,F20.1,T30,F20.1,T51,F15.5,T67,F15.5)') count,X**count,FactorialNum(Count),Esum, exp(X)
  55.       IF ((abs(exp(X)-Esum))<Tol) EXIT
  56.       Countits=Countits+1
  57.       END DO
  58.         write(*,*) "Given a tolerance of",Tol,"it took",Countits,"iterations."
  59.         write(*,*) "The estimated value had",abs(exp(X)-Esum)/exp(X)*100.0
  60.         write(*,*) "% error from the actual value of",exp(x),"."
  61.    ELSE
  62.         write(*,*) "Please define iterations or convergence criteria."
  63.    END IF
  64.  
  65.  
  66. CONTAINS
  67.  !--FactorialNum--------------------------------------------------------
  68.  ! This program calculates the factorial Number! of Number which is 1 &
  69.  ! if Number=0, 1*2*...*Number if Number>0.
  70.  !
  71.  ! Accepts:Number
  72.  ! Returns:FactorialNum
  73.  !----------------------------------------------------------------------
  74.  FUNCTION FactorialNum (Number)
  75.  Integer, INTENT (IN)::Number
  76.  Integer::count
  77.  real:: FactorialNum
  78.  
  79.  !Calculate FactorialNum
  80.  FactorialNum=1
  81.  DO count=2, Number
  82.     FactorialNum=FactorialNum*count
  83.  END DO
  84.  
  85. END FUNCTION FactorialNum
  86.  
  87.  
  88. END
Success #stdin #stdout 0s 2624KB
comments (?)
stdin
copy 
0.8
-1
/
stdout
copy 
 Please enter a value that you would like to find the infinite series of:
 Would you like to define the number of iterations (Y or N)?
 Please define iterations or convergence criteria.
https://ideone.com/xJNRC
language:
Fortran (gfortran 8.3)
created:
13 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!