C Library Functions - circl (3)
NAME
circl(3f) - [M_calcomp:general] draws an arc or spiral (LICENSE:PD)
CONTENTS
Synopsis
Description
Options
Examples
License
SYNOPSIS
subroutine circl(xpage,ypage,tho,thf,ro,rf,di)
DESCRIPTION
CIRCL(3f) is a FORTRAN subroutine that draws, starting at a given point, an arc which may be extended to form a circle or spiral.
OPTIONS
XPAGE,YPAGE are the coordinates of the starting point of the arc in inches. THO is the radius angle, in degrees counterclockwise from the X-axis, for the start of the arc. THF is the radius angle, in degrees counterclockwise from the X-axis, for the end of the arc. RO is the arc’s starting radius, in inches. RF is the arc’s ending radius, in inches. DI is a code used to specify the type of line desired. If DI = 0.0, a solid arc is drawn; 0.5, a dashed arc is drawn.
COMMENTS
THO and THF may be positive or negative. If THO is less than THF, the arc is drawn in a counterclockwise direction; and if THO is greater than THF, the arc is drawn in a clockwise direction.
EXAMPLES
Sample program:
program demo_circl use M_calcomp, only : plots, plot, newpen, circl implicit none character(len=:),allocatable :: lines(:) integer :: i integer :: ipen real :: xstart, ystart real :: start_angle, finish_angle real :: start_radius, finish_radius real :: dash_code integer,parameter :: MOVE=3, DRAW=2 lines=[character(len=80) :: & ’#--------#--------#--------#--------#--------#--------#--------#’, & ’# xstart ! ystart !strt_ang! end_ang! start_r! end_r !dashcode ’, & ’# BIG CIRCLES ’, & ’!4.50 ! 2.5 !0.0 !360.0 !2.00 !2.00 !0.0 !’, & ’!4.00 ! 2.5 !0.0 !360.0 !1.50 !1.50 !0.0 !’, & ’!3.50 ! 2.5 !0.0 !360.0 !1.00 !1.00 !0.0 !’, & ’# LONG SPIRAL ’, & ’!5.00 !-2.5 !0.0 !1440.0 !2.50 !0.25 !0.0 !’, & ’# SPIRAL WITH DASHED LINE ’, & ’!-1.75 ! 2.5 !0.0 !360.0 !0.75 !0.25 !1.0 !’, & ’# CIRCULAR ARC ’, & ’!-2.50 !-2.5 !0.0 !180.0 !0.85 !0.85 !0.0 !’, & ’!-2.50 !-2.5 !-45.0 !-90.0 !0.85 !0.85 !0.0 !’, & ’#--------#--------#--------#--------#--------#--------#--------#’] call plots(0.0,10.0,0.0,10.0) ! initialize graphics call plot(5.0,5.0,-3) ! set origin ! draw a crosshair at origin point <0,0> call crosshair(0.0,0.0,2.0) ! draw some circles using center and radius call circle(-2.5,-2.5,2.5) call circle( 2.5, 2.5,2.5) call circle( 2.5,-2.5,2.5) call circle(-2.5, 2.5,2.5) ! box around 10x10 area call plot(-5.0,-5.0, MOVE) call plot( 5.0,-5.0, DRAW) call plot( 5.0, 5.0, DRAW) call plot(-5.0, 5.0, DRAW) call plot(-5.0,-5.0, DRAW) ! call the values from the table do i = 1,size(lines) write(*,’(a)’)lines(i) ipen=mod(i,8) ipen=merge(5,ipen,ipen.eq.0) call newpen(ipen) if(index(lines(i),’#’).ne.0)cycle read(lines(i),’(7(1x,f8.3))’) xstart,ystart, & start_angle,finish_angle, & start_radius,finish_radius, & dash_code call circl(xstart,ystart, & start_angle,finish_angle, & start_radius,finish_radius, & dash_code) enddo call plot(0.0,0.0,999) ! end graphics contains subroutine crosshair(x,y,s) real,intent(in) :: x,y real,intent(in) :: s call plot(x+s,y ,MOVE) call plot(x-s,y ,DRAW) call plot(x ,y+s,MOVE) call plot(x ,y-s,DRAW) end subroutine crosshair subroutine circle(x,y,r) real,intent(in) :: x,y ! center real,intent(in) :: r ! radius call crosshair(x,y,0.2) call circl(x+r,y,0.0,360.0,r,r,0.0) end subroutine circle end program demo_circl
LICENSE
Public Domain
| Nemo Release 3.1 | circl (3) | February 23, 2025 |
