with: Erik Oosterwal

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Area of an Opening

This collection of routines will return the area of regular and semi-regular shaped holes or openings. I first wrote the routines when I was doing analysis of competitors' appliances and one of the factors being looked at was the size of the openings to various household appliances, such as washers, dryers, and dishwashers.

The formulas are not rocket science, but I got tired of hauling out my cheat sheet of seldom used mathematical expressions and decided to just code them all up in a nifty FORTRAN program to make life a bit easier on me. Besides, by using a standard program for all my calculations I could quickly verify that my calculations were accurate over a long period of time.

The program was originally written in FORTRAN to run on a VAX 11/780, a horrible beast of a machine that you couldn't help but love. I recently found a printout of the routines and decided to share the meaty part of the routines. Rather than bore everyone with all the nifty calls to the various display libraries and VT220 terminal settings, consider the enclosed routines as the guts of the program and put your own display statements in as necessary.

Circular Opening

C 3456789+123456789+123456789+123456789+
      SUBROUTINE CIRC0()
C
      INTEGER TERM
      REAL*16 AREA, DIAM1, PI
      CHARACTER RESP*11, ERRMSG*70
      PI = 3.14159265359
C
   10 WRITE('ENTER DIAMETER 1')
      READ(RESP, '(F8.5)') DIAM1
      IF (DIAM1 .EQ. 0) GOTO 40
C
   20 AREA = (DIAM1/2.0)**2*PI
      WRITE('TOTAL AREA = ', AREA)
      GOTO 10
C
   40 RETURN
      END

Circular Opening with One Cut-out

C 3456789+123456789
      SUBROUTINE CIRC1()
C
      INTEGER TERM
      REAL*16 AREA, DIAM1, DIAM2, TPAREA, RADIUS, THETA
      REAL*16 PIE, TRANGL, PI
      CHARACTER RESP*11, ERRMSG*70
      PI=3.14159265359
C
   10 WRITE ('ENTER DIAMETER 1')
      READ (RESP, '(F8.5)') DIAM1
      IF(DIAM1.EQ.0) GOTO 40
C
   20 WRITE ('ENTER DIAMETER 2')
      READ (RESP, '(F8.5)') DIAM2
      IF (DIAM2.EQ.0) GOTO 40
C
   30 IF(DIAM2.GT.DIAM1)THEN
         ERRMSG='THE DIAMETER (A) MUST BE GREATER THEN ' //
                'THE DEPTH (B) - PLEASE RE-ENTER'
         CALL FDV$PUTL(ERRMSG)                                <- THIS IS VAX 11/780 SPECIFIC
         GOTO 10
         ENDIF
C
      RADIUS = DIAM1/2.0
      D = DIAM2-RADIUS
      THETA = 2.0*(ACOS(D/RADIUS))
      AREA = PI*RADIUS**2
      PIE = PI*RADIUS**2*(THETA/(2.0*PI))
      TRANGL = RADIUS*(SIN(THETA/2.0))*D
      TPAREA = AREA-PIE+TRANGL
C
      WRITE('TOTAL AREA = ', TPAREA)
      GOTO 10
C
   40 RETURN
      END

Circular Opening with Two Cut-outs

Eliptical Opening

Rectangular Opening with Tight or Square Corners

Rectangular Opening with Rounded Corners

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