CSCE150 Fortran Lab 7

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CSCE150 Fortran Lab 7
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outline

• Basic I/O
• formatted output-WRITE
• formatted input-READ
• file processing
• exercise 1
• exercise 2 optional
• exercise 3

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Basic I/O

• Formatted output
• WRITE statement

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Formatted output - WRITE

• Example 2
• INTEGERnum17, num25
• WRITE(,200) num1,num2
• 200 FORMAT(2I5)

• Example 1
• INTEGERnum7
• WRITE(,100) num
• 100 FORMAT (I5)

repeat count
integer descriptor
width
FORMAT statement holds the formatting info

• Example 3
• INTEGERnum17 REALnum25.31
• WRITE(,300) num1,num2
• 300 FORMAT(num1, I5, num2,F5.2)

real descriptor
of digits after the point
5
format descriptors

• integer output I
• real output F or E (exponential notation)
• true scientific notation ES
• logical output L
• character output A
• horizontal positioning X and T
• page 193-new textbook
• page 182-old textbook

5X insert 5 spaces
T6 go to column 5
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Basic I/O

• Formatted input
• READ statement

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Formatted input - READ

• Example 2
• INTEGERnum1, num2
• READ(,200) num1,num2
• 200 FORMAT(2I5)

• Example 1
• INTEGERnum
• READ(,100) num
• 100 FORMAT (3X,I3)

repeat count
width
skip the first 3
integer descriptor
FORMAT statement holds the formatting info

• Example 3
• INTEGERnum1 REALnum2
• READ(,(I5, F5.2)) num1,num2

real descriptor
of digits after the decimal point
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format descriptors
repeat count
field width

• integer input I rIw
• real input F rFw.d
• logical input L rLw (T or F)
• character input A rA rAw
• horizontal positioning X and T
• page 212-new textbook
• page 200-old textbook

of digits after the decimal point
5X skip 5 columns
read the same data twice in two different
formats CHARACTER(len6)string INTEGERinput R
EAD(,(I6,T1,A6)) input, string
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File processing

• three steps of file processing
• open associates a file with an i/o unit number
• read or write
• close closes a file and releases the i/o unit
  number

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• OPEN statement
• open a file for input
• OPEN(UNITunit_num, FILEfilename,
  STATUS'OLD',
• ACTION'READ', IOSTATierror)
• open a file for output
• Open (UNITunit_num, FILEfilename, STATUS'NEW
  ',
• ACTION'WRITE', IOSTATierror)
• Open (UNITunix_num, FILEfilename,
  STATUS'REPLACE',
• ACTION'WRITE', IOSTATierror)
• unit_num an integer used to identify the file
• STATUS
• OLD file exists before opening (file reading)
• NEW create a new file (file doesnt exist before
  opening)
• REPLACE create a new file (if the file with the
  same name exist, then overwrite it)
• ierror an integer error code
• 0 success non-zero error

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• READ and WRITE to disk files
• READ
• OPEN(UNIT8, FILEinput.dat, STATUSOLD,
  IOSTATierror)
• READ(8,) x,y,z
• WRITE
• OPEN(UNIT7, FILEoutput.dat, STATUSREPLACE,
  
• IOSTATierror)
• WRITE(7,100) x,y,z
• 100 FORMAT(X,F10.2,Y,F10.2,Z,F10.2)
• CLOSE
• CLOSE(UNITunit_num)

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exercise 1

• PROGRAM table
• IMPLICIT NONE
• INTEGERi, square
• WRITE(,100)
• 100 FORMAT(Table of square)
• WRITE(,200)
• 200 FORMAT(number, 9X, square)
• WRITE(,300)
• 300 FORMAT(, 9X, )
• DO i1,10
• squareii
• WRITE(,400) i, square
• END DO
• 400 FORMAT(I4, 12X, I4)

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• Rewrite the above program to add two new columns
  which are square_root and cube.

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exercise 2-optional

• Write a program to get two 3-digit integers from
  the user, print the sum and difference in a
  pretty way.

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exercise 3

• get 5 integer values from the user
• calculate the cube of each value
• write the cube values to a file (output.txt)