streamplot_demo.f90 Source File

program streamplot_demo
    use fortplot
    use, intrinsic :: iso_fortran_env, only: real64
    implicit none
    
    integer, parameter :: nx = 20, ny = 20
    real(real64), dimension(nx) :: x
    real(real64), dimension(ny) :: y
    real(real64), dimension(nx, ny) :: u, v
    integer :: i, j
    type(figure_t) :: fig
    
    ! Create grid
    do i = 1, nx
        x(i) = -2.0_real64 + 4.0_real64 * real(i-1, real64) / real(nx-1, real64)
    end do
    
    do j = 1, ny
        y(j) = -2.0_real64 + 4.0_real64 * real(j-1, real64) / real(ny-1, real64)
    end do
    
    ! Create circular flow field
    do j = 1, ny
        do i = 1, nx
            u(i,j) = -y(j)
            v(i,j) = x(i)
        end do
    end do
    
    ! Create figure and add streamplot
    call figure(figsize=[8.0_wp, 6.0_wp])
    ! Try with broken_streamlines=False to allow circles to complete
    ! (This parameter doesn't exist yet in our API, so let's just use default for now)
    call streamplot(x, y, u, v, density=1.0_real64)
    call xlabel('X')
    call ylabel('Y')
    call title('Streamline Plot Demo - Circular Flow')
    
    ! Save figure
    call savefig('output/example/fortran/streamplot_demo/streamplot_demo.png')
    call savefig('output/example/fortran/streamplot_demo/streamplot_demo.pdf')
    call savefig('output/example/fortran/streamplot_demo/streamplot_demo.txt')
    
    print *, 'Streamplot demo completed!'
    
end program streamplot_demo