# $Id$
##
##  This file is part of pyFormex 0.8.9  (Fri Nov  9 10:49:51 CET 2012)
##  pyFormex is a tool for generating, manipulating and transforming 3D
##  geometrical models by sequences of mathematical operations.
##  Home page: http://pyformex.org
##  Project page:  http://savannah.nongnu.org/projects/pyformex/
##  Copyright 2004-2012 (C) Benedict Verhegghe (benedict.verhegghe@ugent.be)
##  Distributed under the GNU General Public License version 3 or later.
##
##
##  This program is free software: you can redistribute it and/or modify
##  it under the terms of the GNU General Public License as published by
##  the Free Software Foundation, either version 3 of the License, or
##  (at your option) any later version.
##
##  This program is distributed in the hope that it will be useful,
##  but WITHOUT ANY WARRANTY; without even the implied warranty of
##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##  GNU General Public License for more details.
##
##  You should have received a copy of the GNU General Public License
##  along with this program.  If not, see http://www.gnu.org/licenses/.
##

"""BeamFreq

This example shows the first natural vibration modes of an elastic beam.
It requires an external program, calix, which can be downloaded from
ftp://bumps.ugent.be/pub/calix/
Make sure you have version 1.5-a8 or higher.

"""
from __future__ import print_function
_status = 'checked'
_level = 'normal'
_topics = ['FEA','curve','drawing']
_techniques = ['external','viewport']

from gui.draw import *
from plugins.curve import *
import simple

def check_calix(version='1.5-a8'):
    """Check that we have the required calix version"""
    ok = utils.checkVersion('calix',version,True) >= 0
    if not ok:
        showText("""..

Error
-----
An error occurred when I tried to find the program 'calix'.
This probably means that calix is not installed on your system,
or that the installed version is not one I can use for this example.

Calix is a free program and you can install it as follows:

- download calix (%s or higher) from ftp://bumps.ugent.be/pub/calix/
- unpack, compile and install (as root)::

   tar xvzf calix-%s.tar.gz
   cd calix-1.5
   make
   (sudo) make install
""" % (version,version))
    return ok


def geometry():
    global M
    n = 16
    nshow = 4
    bcons = ['cantilever','simply supported']
    keep = False
    verbose = False

    res = askItems([
        _I('n',n,text='number of elements along beam'),
        _I('nshow',nshow,text='number of natural modes to show'),
        _I('bcon',bcons[0],text='beam boundary conditions',choices=bcons),
        _I('keep',keep,text='keep data and result files'),
        _I('verbose',verbose,text='show intermediate information'),
        ])
    if not res:
        return

    globals().update(res)
    F = simple.line([0.,0.,0.],[0.,1.,0.],n)
    M = F.toMesh()
    return M


def compute():
    global nshow,a,freq
    nnod = M.ncoords()
    nel = M.nelems()
    nmat = 1
    iout = 1

    # init
    s=""";calix script written by pyFormex (example BeamFreq)
start
use program 'frame.cal'
endtext
"""

    # params
    s += " %s %s %s %s\n" % (nnod+1,nel,nmat,iout)
    # nodes
    for i,x in enumerate(M.coords):
        s += "%5d%10.3e%10.3e%10.3e\n" %  ((i+1,)+tuple(x))
    # orientation node
    s += "%5d%10.3e%10.3e%10.3e\n\n" %  (nnod+1,0.0,0.0,1.0)

    # boundary conditions
    s += "%5s    0    1    1    1    1    0%5s    1\n" %  (2,nnod-2)
    s += "%5s    1    1    1    1    1    1\n" % (nnod+1)
    if bcon == 'cantilever':
        # boundary conditions for cantilever
        s += "%5s    1    1    1    1    1    1\n" % (1)
        s += "%5s    0    1    1    1    1    0\n" % (nnod)
    else:
        # boundary conditions for simply supported
        s += "%5s    1    1    1    1    1    0\n" % (1)
        s += "%5s    1    1    1    1    1    0\n" % (nnod)
    s += '\n'
    # material
    s += "      3.d6     1.2d6      1.00     3000.      1.00     70.d4    110.d4\n"
    # elems
    fmt = "%5s"*(M.nplex()+3) + '\n'
    for i,e in enumerate(M.elems+1):
        s += fmt % ((i+1,1)+tuple(e)+(nnod+1,))

    # action and output in a format we can easily read back
    s += """
exec frame_ev
endtext
intvar name nnod 1
intvar name ndof 7
file open 'test.out' write seq 17
user printf '(i5)' nnod $17
user printf '(i5)' ndof $17
user printf '(5g13.4)' EIG $17
user printf '(5g13.4)' DISPL $17
file close $17
stop
"""
    import os
    savedir = os.getcwd()
    #    tmpdir = None
    #    if not checkWorkdir():
    tmpdir = utils.tempDir()
    chdir(tmpdir)
    print("Using a temporary directory: %s" % tmpdir)

    fil = open('temp.dta','w')
    fil.write(s)
    fil.close()

    if verbose:
        # show calix input data
        showFile('temp.dta')

    # run calix
    cmd = "calix temp.dta temp.res"
    if os.path.exists('test.out'):
        os.remove('test.out')

    sta,out = utils.runCommand(cmd)

    if verbose:
        # show calix output
        showText(out)
        showFile('temp.res')
        showFile('test.out')

    # read results from eigenvalue analysis
    fil = open('test.out','r')
    nnod,ndof = fromfile(fil,sep=' ',count=2,dtype=int)
    eig = fromfile(fil,sep=' ',count=4*ndof).reshape(ndof,4)

    nshow = min(nshow,ndof)
    freq = eig[:nshow,2]
    basefreq = freq[0]
    print("Frequencies: %s" % freq)
    print("Multipliers: %s" % (freq/freq[0]))

    a = fromfile(fil,sep=' ',).reshape(-1,nnod,6)
    # print a.shape
    # remove the extra node
    a = a[:,:-1,:]

    chdir(savedir)
    if not keep:
        print("Removing temporary directory: %s" % tmpdir)
        utils.removeTree(tmpdir)


def drawDeformed(M,u,r):
    xd = M.coords.copy()
    xd[:,0] += u
    c = NaturalSpline(xd)
    draw(c,color=red)
    draw(c.pointsOn())


def showResults(hscale):
    for i in range(nshow):
        viewport(i)
        clear()
        transparent(False)
        lights(False)
        linewidth(2)
        draw(M)
        ai = a[i]
        u = ai[:,0]
        imax = argmax(abs(u))
        r = ai[:,5]
        sc = hscale / u[imax]
        u *= sc
        r *= sc
        # print u,r
        drawDeformed(M,u,r)
        fi = freq[i]
        mi = fi/freq[0]
        drawText('%s Hz = %.2f f0' % (fi,mi),20,20,size=20)


def run():
    resetAll()
    clear()
    if not check_calix():
        return

    M = geometry()
    if M:
        compute()
        layout(nshow,ncols=4)
        showResults(hscale = 0.5)

if __name__ == 'draw':
    run()
# End
