Create A Histogram Of Random Numbers Chosen With Normal Distribution Using fortran 95 Assignment Solution.

PROGRAM Program1

IMPLICIT NONE

    REAL, PARAMETER :: PI=3.14159265358979323846

    INTEGER, PARAMETER :: NGEN1 = 13000

    REAL, PARAMETER :: AVG1 = 22.0

    REAL, PARAMETER :: STDDEV1 = 2.5

    INTEGER, PARAMETER :: NGEN2 = 7000

    REAL, PARAMETER :: AVG2 = 15.5

    REAL, PARAMETER :: STDDEV2 = 1.0

    INTEGER :: i

    REAL :: n1, n2, ngauss

    INTEGER :: new_seed;

    ! Read seed

    print*, "Seed?"

    read*, new_seed

    ! set seed for random generator

    call srand(new_seed)

    open(11,FILE="Bumps.txt", STATUS='REPLACE', ACCESS='SEQUENTIAL',ACTION='WRITE')

    ! Generate 13000 numbers with gaussian distribution

    ! with average= 22.0 and stddev = 2.5

    do i = 1, NGEN1

        ! generate two numbers

        n1 = rand()

        n2 = rand()

        ! generate normally distributed number

        ngauss = boxMuller(n1, n2, AVG1, STDDEV1)

        write(11, *) ngauss

    end do

    ! Generate 7000 numbers with gaussian distribution

    ! with average= 15.5 and stddev = 1.0

    do i = 1, NGEN2

        ! generate two numbers

        n1 = rand()

        n2 = rand()

        ! generate normally distributed number

        ngauss = boxMuller(n1, n2, AVG2, STDDEV2)

        write(11, *) ngauss

    end do

    close(11)

CONTAINS

! generate a random number with gaussian distribution

! and given average m and standard deviation s, using

! the Box-Muller algorithm based on the uniformly

! distributed numbers n1 and n2

REAL FUNCTION boxMuller(n1, n2, m, s)

REAL, INTENT(IN) :: n1, n2, m, s

REAL :: r, z1

    r = sqrt(-2.0 * log(n1))

    z1 = r*cos(2.0 * PI * n2)

    ! transform to given median and deviation

    boxMuller = m + s*z1

END FUNCTION boxMuller

END PROGRAM Program1

PROGRAM Program2

IMPLICIT NONE

    INTEGER, PARAMETER :: NNUMBERS = 20000

    REAL, PARAMETER :: HIST_MIN = 10

    REAL, PARAMETER :: HIST_MAX = 30

    INTEGER, PARAMETER :: HIST_NBOXES = 100

    INTEGER :: i, box

    REAL :: n, boxwid, start

    INTEGER :: histogram(100)

    ! initialize histogram to zero

    do i = 1, HIST_NBOXES

        histogram(i) = 0

    end do

    ! box size

    boxwid = (HIST_MAX - HIST_MIN) / HIST_NBOXES

    ! Read the 20000 numbers from the file and

    ! build histogram with the data

    open(11,FILE="Bumps.txt")

    do i = 1, NNUMBERS

        read(11, *) n

        if (n >= HIST_MIN .and. n <= HIST_MAX) then

            box = (n - HIST_MIN)/boxwid + 1

            histogram(box) = histogram(box) + 1

        end if

    end do

    close(11)

    ! write histogram to a file

    open(12,FILE="BumpsHist.txt", STATUS='REPLACE', ACCESS='SEQUENTIAL',ACTION='WRITE')

    do i = 1, HIST_NBOXES

        start = (i - 1)*boxwid + HIST_MIN

        write(12, *) start, histogram(i)

    end do

    close(12)

END PROGRAM Program2