added script to calculate numerical derivative of ASCIItable data

This commit is contained in:
Philip Eisenlohr 2017-11-28 10:59:53 -05:00
parent e4700cda25
commit 3b96fac8bd
1 changed files with 121 additions and 0 deletions

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processing/post/addDerivative.py Executable file
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#!/usr/bin/env python2.7
# -*- coding: UTF-8 no BOM -*-
import os,sys,math
import numpy as np
from optparse import OptionParser
import damask
scriptName = os.path.splitext(os.path.basename(__file__))[0]
scriptID = ' '.join([scriptName,damask.version])
def derivative(coordinates,what):
result = np.empty_like(what)
# use differentiation by interpolation
# as described in http://www2.math.umd.edu/~dlevy/classes/amsc466/lecture-notes/differentiation-chap.pdf
result[1:-1,:] = + what[1:-1,:] * (2.*coordinates[1:-1]-coordinates[:-2]-coordinates[2:]) / \
((coordinates[1:-1]-coordinates[:-2])*(coordinates[1:-1]-coordinates[2:])) \
+ what[2:,:] * (coordinates[1:-1]-coordinates[:-2]) / \
((coordinates[2:]-coordinates[1:-1])*(coordinates[2:]-coordinates[:-2])) \
+ what[:-2,:] * (coordinates[1:-1]-coordinates[2:]) / \
((coordinates[:-2]-coordinates[1:-1])*(coordinates[:-2]-coordinates[2:])) \
result[0,:] = (what[0,:] - what[1,:]) / \
(coordinates[0] - coordinates[1])
result[-1,:] = (what[-1,:] - what[-2,:]) / \
(coordinates[-1] - coordinates[-2])
return result
# --------------------------------------------------------------------
# MAIN
# --------------------------------------------------------------------
parser = OptionParser(option_class=damask.extendableOption, usage='%prog options [file[s]]', description = """
Add column(s) containing numerical derivative of requested column(s) with respect to given coordinates.
""", version = scriptID)
parser.add_option('-c','--coordinates',
dest = 'coordinates',
type = 'string', metavar='string',
help = 'heading of coordinate column')
parser.add_option('-l','--label',
dest = 'label',
action = 'extend', metavar = '<string LIST>',
help = 'heading of column(s) to differentiate')
(options,filenames) = parser.parse_args()
if options.coordinates is None:
parser.error('no coordinate column specified.')
if options.label is None:
parser.error('no data column specified.')
# --- loop over input files -------------------------------------------------------------------------
if filenames == []: filenames = [None]
for name in filenames:
try: table = damask.ASCIItable(name = name,
buffered = False)
except: continue
damask.util.report(scriptName,name)
# ------------------------------------------ read header ------------------------------------------
table.head_read()
# ------------------------------------------ sanity checks ----------------------------------------
errors = []
remarks = []
columns = []
dims = []
if table.label_dimension(options.coordinates) != 1:
errors.append('coordinate column {} is not scalar.'.format(options.coordinates))
for what in options.label:
dim = table.label_dimension(what)
if dim < 0: remarks.append('column {} not found...'.format(what))
else:
dims.append(dim)
columns.append(table.label_index(what))
table.labels_append('d({})/d({})'.format(what,options.coordinates) if dim == 1 else
['{}_d({})/d({})'.format(i+1,what,options.coordinates) for i in range(dim)] ) # extend ASCII heade table.labels_append('norm{}({})'.format(options.norm.capitalize(),what)) # extend ASCII header with new labels
if remarks != []: damask.util.croak(remarks)
if errors != []:
damask.util.croak(errors)
table.close(dismiss = True)
continue
# ------------------------------------------ assemble header --------------------------------------
table.info_append(scriptID + '\t' + ' '.join(sys.argv[1:]))
table.head_write()
# ------------------------------------------ process data ------------------------------------------
table.data_readArray()
mask = []
for col,dim in zip(columns,dims): mask += range(col,col+dim) # isolate data columns to differentiate
differentiated = derivative(table.data[:,table.label_index(options.coordinates)].reshape((len(table.data),1)),
table.data[:,mask]) # calculate numerical derivative
table.data = np.hstack((table.data,differentiated))
# ------------------------------------------ output result -----------------------------------------
table.data_writeArray()
# ------------------------------------------ output finalization -----------------------------------
table.close() # close ASCII tables