def wfdmfile(self):
        if os.path.exists('fdmfile.bak'):
            print('fdmfile.bak exists, good')
        else:
            subprocess.call('cp fdmfile.txt fdmfile.bak', shell=True)
            print('copied fdmfile.txt to fmdfile.bak')
        #
        s = Template('!fdmfile.txt automatically created by ${creator} on ${today} (for convolution)\n\
!--------------------------------------------------------------------!\n\
! Number of calculations\n\
 1\n\
! FOR CONVOLUTION STEP\n\
convfile.txt\n\
!--------------------------------------------------------------------!\n\
')
        outstr = s.substitute(self.opts)
        f = open('fdmfile.txt', 'w')
        f.write(outstr)
        f.close()
write a simple fdmfile.txt to enable the convolution
dataset/ETHPy150Open xraypy/xraylarch/plugins/math/convolution1D.py/FdmnesConv.wfdmfile