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Hi Andrea,

We have added Python support in the model preparation stage in jEPlus. Ivan has also made an example script using Eppy to apply WWR to each and every window in the external walls. Below is the script.

You can find further details on how to use Python pre-processing in jEPlus, and download the new version, here: http://www.jeplus.org/wiki/doku.php?id=misc:python_preproc

# python script for pre-processing: This script takes WWR value from the argument list and modifies all the windows in the IDF model
# This script is designed to work with jEPlus v1.6.4 and later, with the @python? syntax
# @author: Dr Ivan Korolija [ivan.korolija@gmail.com]
# Arguments:
#   sys.argv[1]  -  project's base folder where the project files are located
#   sys.argv[2]  -  folder of the current case where in.idf is located
#   sys.argv[3]  -  Other arguments specified in the parameter definition. They are passed in as a ',' delimited string
#   sys.argv[4]  -  folder of the binary files of the simulation program, e.g. the location of Energy+.idd

import os
from eppy.modeleditor import IDF
import sys
import math

# function for calculating wall width and height
def wall_width_height(coordinates):
    ulc = coordinates[0]  # upper left corner coordinates
    blc = coordinates[1]  # bottom left corner coordinates
    brc = coordinates[2]  # bottom right corner coordinates

    # calculate wall width and height by using the Euclidean distance
    w = math.sqrt(math.pow(
        (brc[0] - blc[0]), 2) + math.pow((brc[1] - blc[1]), 2) +
        math.pow((brc[2] - blc[2]), 2))
    h = math.sqrt(math.pow(
        (ulc[0] - blc[0]), 2) + math.pow((ulc[1] - blc[1]), 2) +
        math.pow((ulc[2] - blc[2]), 2))
    return w, h  # return wall width and height
# End 


# path to E+ idd file (required by eppy)
iddfile = os.path.join(sys.argv[4], 'Energy+.idd')
IDF.setiddname(iddfile)

# path to energyplus input file within each simulated folder
idf = os.path.join(sys.argv[2], 'in.idf')

# glazing ratio convert to integer
gr = int(sys.argv[3])

idf = IDF(idf)  # read idf file to eppy
# extract window and wall objects
window_objects = idf.idfobjects['Window'.upper()]
wall_object = idf.idfobjects['BuildingSurface:Detailed'.upper()]

# loop through window objects
for window in window_objects:
    # find the base surface for the window
    win_base_surface = window.Building_Surface_Name

    # loop through the wall objects
    for wall in wall_object:
        # when wall name equals to the window base surface name extract coords
        if wall.Name == win_base_surface:
            coord = wall.coords
            # calculate wall width and height
            w, h = wall_width_height(coord)
            # calculate wall length and height as a function of glazing ratio
            wl = w * math.sqrt(gr / 100)  # window length
            wh = h * math.sqrt(gr / 100)  # window height
            # starting X/Z coordinates relative to the wall bottom left corner
            x = (w - wl) / 2
            z = (h - wh) / 2

    # coords and window H/L converted into strings and applied to window object
    window.Starting_X_Coordinate = '%.2f' % x
    window.Starting_Z_Coordinate = '%.2f' % z
    window.Length = '%.2f' % wl
    window.Height = '%.2f' % wh

# save the updated idf file
idf.saveas('in.idf')

# Done