pyfai 0.10.2-1 / usr / lib / python2.7 / dist-packages / pyFAI / spline.py

# !/usr/bin/env python
# -*- coding: utf-8 -*-
# ##########################################################################
# Written 2009-12-22 by Jérôme Kieffer
# Copyright (C) 2009 European Synchrotron Radiation Facility
#                       Grenoble, France
#
#    Principal authors: Jérôme Kieffer  (jerome.kieffer@esrf.fr)
#
#    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/>.
# #######################################################################################

"""
This is piece of software aims at manipulating spline files
describing for geometric corrections of the 2D detectors using cubic-spline.

Mainly used at ESRF with FReLoN CCD camera.
"""

__author__ = "Jérôme Kieffer"
__contact__ = "Jerome.Kieffer@esrf.eu"
__license__ = "GPLv3+"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"

import os
import time
import sys
import numpy
import scipy
import logging
import scipy.optimize
import scipy.interpolate
from scipy.interpolate import fitpack
import traceback
logger = logging.getLogger("pyFAI.spline")


class Spline(object):
    """
    This class is a python representation of the spline file

    Those file represent cubic splines for 2D detector distortions and
    makes heavy use of fitpack (dierckx in netlib) --- A Python-C
    wrapper to FITPACK (by P. Dierckx). FITPACK is a collection of
    FORTRAN programs for curve and surface fitting with splines and
    tensor product splines.  See
    _http://www.cs.kuleuven.ac.be/cwis/research/nalag/research/topics/fitpack.html
    or _http://www.netlib.org/dierckx/index.html
    """

    def __init__(self, filename=None):
        """
        This is the constructor of the Spline class.

        @param filename: name of the ascii file containing the spline
        @type filename: str
        """
        self.splineOrder = 3  # This is the default, so cubic splines
        self.lenStrFloat = 14  # by default one float is 14 char in ascii
        self.xmin = None
        self.ymin = None
        self.xmax = None
        self.ymax = None
        self.xDispArray = None
        self.yDispArray = None
        self.xSplineKnotsX = []
        self.xSplineKnotsY = []
        self.xSplineCoeff = []
        self.ySplineKnotsX = []
        self.ySplineKnotsY = []
        self.ySplineCoeff = []
        self.pixelSize = None
        self.grid = None
        self.filename = None
        if filename is not None:
            self.read(filename)

    def __repr__(self):
        lst = ["Array size: x= %s - %s\ty= %s - %s" % \
            (self.xmin, self.xmax, self.ymin, self.ymax)]
        lst.append("Pixel size = %s microns, Grid spacing = %s" % \
            (self.pixelSize, self.grid))
        lst.append("X-Displacement spline %i X_knots, %i Y_knots and %i coef: \
                should be (X_knot-1-X_order)*(Y_knot-1-Y_order)" % (len(self.xSplineKnotsX),
                                                                  len(self.xSplineKnotsY),
                                                                  len(self.xSplineCoeff)))
        lst.append("Y-Displacement spline %i X_knots, %i Y_knots and %i coef: "
                "should be (X_knot-1-X_order)*(Y_knot-1-Y_order)" % (len(self.ySplineKnotsX),
                                                                     len(self.ySplineKnotsY),
                                                                     len(self.ySplineCoeff)))
        return os.linesep.join(lst)

    def zeros(self, xmin=0.0, ymin=0.0, xmax=2048.0, ymax=2048.0,
              pixSize=None):
        """
        Defines a spline file with no ( zero ) displacement.

        @param xmin: minimum coordinate in x, usually zero
        @type xmin: float
        @param xmax: maximum coordinate in x (+1) usually 2048
        @type xmax: float
        @param ymin: minimum coordinate in y, usually zero
        @type ymin: float
        @param ymax: maximum coordinate y (+1) usually 2048
        @type ymax: float
        @param pixSize: size of the pixel
        @type pixSize: float
        """
        self.xmin = xmin
        self.ymin = ymin
        self.xmax = xmax
        self.ymax = ymax
        self.xDispArray = numpy.zeros((int(xmax - xmin + 1),
                                       int(ymax - ymin + 1)))
        self.yDispArray = numpy.zeros((int(xmax - xmin + 1),
                                       int(ymax - ymin + 1)))
        if pixSize:
            self.pixelSize = pixSize

    def zeros_like(self, other):
        """
        Defines a spline file with no ( zero ) displacement with the
        same shape as the other one given.

        @param other: another Spline instance
        @type other: Spline instance
        """
        self.zeros(self, other.xmin, other.ymin, other.xmax, other.ymax)

    def read(self, filename):
        """
        read an ascii spline file from file

        @param filename: file containing the cubic spline distortion file
        @type filename: str
        """
        if not os.path.isfile(filename):
            raise IOError("Spline File does not exist %s" % filename)
        self.filename = filename
        stringSpline = [i.rstrip() for i in open(filename)]
        try:
            indexLine = 0
            for oneLine in stringSpline:
                stripedLine = oneLine.strip().upper()
                if stripedLine == "VALID REGION":
                    data = stringSpline[indexLine + 1]
                    self.xmin = float(data[self.lenStrFloat * 0:self.lenStrFloat * 1])
                    self.ymin = float(data[self.lenStrFloat * 1:self.lenStrFloat * 2])
                    self.xmax = float(data[self.lenStrFloat * 2:self.lenStrFloat * 3])
                    self.ymax = float(data[self.lenStrFloat * 3:self.lenStrFloat * 4])
                elif stripedLine == "GRID SPACING, X-PIXEL SIZE, Y-PIXEL SIZE":
                    data = stringSpline[indexLine + 1]
                    self.grid = float(data[:self.lenStrFloat])
                    self.pixelSize = \
                        (float(data[self.lenStrFloat:self.lenStrFloat * 2]),
                         float(data[self.lenStrFloat * 2:self.lenStrFloat * 3]))
                elif stripedLine == "X-DISTORTION":
                    data = stringSpline[indexLine + 1]
                    [splineKnotsXLen, splineKnotsYLen] = \
                        [int(i) for i in data.split()]
                    databloc = []
                    for line in stringSpline[indexLine + 2:]:
                        if len(line) > 0:
                            for i in range(len(line) / self.lenStrFloat):
                                databloc.append(float(line[i * self.lenStrFloat: (i + 1) * self.lenStrFloat]))
                        else:
                            break
                    self.xSplineKnotsX = numpy.array(databloc[:splineKnotsXLen], dtype=numpy.float32)
                    self.xSplineKnotsY = numpy.array(databloc[splineKnotsXLen:splineKnotsXLen + splineKnotsYLen], dtype=numpy.float32)
                    self.xSplineCoeff = numpy.array(databloc[splineKnotsXLen + splineKnotsYLen:], dtype=numpy.float32)
                elif stripedLine == "Y-DISTORTION":
                    data = stringSpline[indexLine + 1]
                    [splineKnotsXLen, splineKnotsYLen] = [int(i) for i in data.split()]
                    databloc = []
                    for line in stringSpline[indexLine + 2:]:
                        if len(line) > 0:
                            for i in range(len(line) / self.lenStrFloat):
                                databloc.append(float(line[i * self.lenStrFloat:(i + 1) * self.lenStrFloat]))
                        else:
                            break
                    self.ySplineKnotsX = numpy.array(databloc[:splineKnotsXLen], dtype=numpy.float32)
                    self.ySplineKnotsY = numpy.array(databloc[splineKnotsXLen:splineKnotsXLen + splineKnotsYLen], dtype=numpy.float32)
                    self.ySplineCoeff = numpy.array(databloc[ splineKnotsXLen + splineKnotsYLen:], dtype=numpy.float32)
    # Keep this at the end
                indexLine += 1
        except:
            traceback.print_exc()
            raise IOError("Spline File parsing error: %s" % (filename))

    def comparison(self, ref, verbose=False):
        """
        Compares the current spline distortion with a reference

        @param ref: another spline file
        @type ref: Spline instance
        @param verbose: print or not pylab plots
        @type verbose: bool

        @return: True or False depending if the splines are the same or not
        @rtype: bool
        """
        self.spline2array()
        ref.spline2array()
        deltax = (self.xDispArray - ref.xDispArray)
        deltay = (self.yDispArray - ref.yDispArray)
        histX = numpy.histogram(deltax.reshape(deltax.size), bins=100)
        histY = numpy.histogram(deltay.reshape(deltay.size), bins=100)
        histXdr = (histX[1][1:] + histX[1][:-1]) / 2.0
        histYdr = (histY[1][1:] + histY[1][:-1]) / 2.0
        histXmax = histXdr[histX[0].argmax()]
        histYmax = histYdr[histY[0].argmax()]
        maxErrX = abs(deltax).max()
        maxErrY = abs(deltay).max()
        curvX = scipy.interpolate.interp1d(histXdr, histX[0] - histX[0].max() / 2.0)
        curvY = scipy.interpolate.interp1d(histYdr, histY[0] - histY[0].max() / 2.0)
        fFWHM_X = scipy.optimize.bisect(curvX , histXmax, histXdr[-1]) - scipy.optimize.bisect(curvX , histXdr[0], histXmax)
        fFWHM_Y = scipy.optimize.bisect(curvY , histYmax, histYdr[-1]) - scipy.optimize.bisect(curvY , histYdr[0], histYmax)
        logger.info("Analysis of the difference between two splines")
        logger.info("Maximum error in X= %.3f pixels,\t in Y= %.3f pixels." % (maxErrX, maxErrY))
        logger.info("Maximum of histogram in X= %.3f pixels,\t in Y= %.3f pixels." % (histXmax, histYmax))
        logger.info("Mean of histogram in X= %.3f pixels,\t in Y= %.3f pixels." % (deltax.mean(), deltay.mean()))
        logger.info("FWHM in X= %.3f pixels,\t in Y= %.3f pixels." % (fFWHM_X, fFWHM_Y))

        if verbose:
            import pylab
            pylab.plot(histXdr, histX[0], label="error in X")
            pylab.plot(histYdr, histY[0], label="error in Y")
            pylab.legend()
            pylab.show()
        return (fFWHM_X < 0.05) and (fFWHM_Y < 0.05) and (maxErrX < 0.5) and (maxErrY < 0.5) \
                and (deltax.mean() < 0.01) and(deltay.mean() < 0.01) and (histXmax < 0.01) and (histYmax < 0.01)

    def spline2array(self, timing=False):
        """
        Calculates the displacement matrix using fitpack
        bisplev(x, y, tck, dx = 0, dy = 0)

        @param timing: profile the calculation or not
        @type timing: bool

        @return: Nothing !
        @rtype: float or ndarray

        Evaluate a bivariate B-spline and its derivatives. Return a
        rank-2 array of spline function values (or spline derivative
        values) at points given by the cross-product of the rank-1
        arrays x and y. In special cases, return an array or just a
        float if either x or y or both are floats.
        """
        if self.xDispArray is None:
            x_1d_array = numpy.arange(self.xmin, self.xmax + 1)
            y_1d_array = numpy.arange(self.ymin, self.ymax + 1)
            startTime = time.time()
            self.xDispArray = fitpack.bisplev(
                x_1d_array, y_1d_array, [self.xSplineKnotsX,
                                         self.xSplineKnotsY,
                                         self.xSplineCoeff,
                                         self.splineOrder,
                                         self.splineOrder],
                dx=0, dy=0).transpose()
            intermediateTime = time.time()
            self.yDispArray = fitpack.bisplev(
                x_1d_array, y_1d_array, [self.ySplineKnotsX,
                                         self.ySplineKnotsY,
                                         self.ySplineCoeff,
                                         self.splineOrder,
                                         self.splineOrder],
                dx=0, dy=0).transpose()
            if timing:
                logger.info("Timing for: X-Displacement spline evaluation: %.3f sec,"
                      " Y-Displacement Spline evaluation:  %.3f sec." %
                      ((intermediateTime - startTime),
                       (time.time() - intermediateTime)))

    def splineFuncX(self, x, y):
        """
        Calculates the displacement matrix using fitpack for the X
        direction on the given grid.

        @param x: points of the grid in the x direction
        @type x: ndarray
        @param y: points of the grid  in the y direction
        @type y: ndarray

        @return: displacement matrix for the X direction
        @rtype: ndarray
        """
        if x.ndim == 2:
            if abs(x[1:, :] - x[:-1, :] - numpy.zeros((x.shape[0] - 1, x.shape[1]))).max() < 1e-6:
                x = x[0]
                y = y[:, 0]
            elif abs(x[:, 1:] - x[:, :-1] - numpy.zeros((x.shape[0], x.shape[1] - 1))).max() < 1e-6:
                x = x[:, 0]
                y = y[0]

        xDispArray = fitpack.bisplev(
            x, y, [self.xSplineKnotsX,
                   self.xSplineKnotsY,
                   self.xSplineCoeff,
                   self.splineOrder,
                   self.splineOrder ],
            dx=0, dy=0).transpose()

        return xDispArray

    def splineFuncY(self, x, y):
        """
        calculates the displacement matrix using fitpack for the Y
        direction

        @param x: points in the x direction
        @type x: ndarray
        @param y: points in the y direction
        @type y: ndarray

        @return: displacement matrix for the Y direction
        @rtype: ndarray
        """
        if x.ndim == 2:
            if abs(x[1:, :] - x[:-1, :] - numpy.zeros((x.shape[0] - 1, x.shape[1]))).max() < 1e-6:
                x = x[0]
                y = y[:, 0]
            elif abs(x[:, 1:] - x[:, :-1] - numpy.zeros((x.shape[0], x.shape[1] - 1))).max() < 1e-6:
                x = x[:, 0]
                y = y[0]

        yDispArray = fitpack.bisplev(
            x, y, [self.ySplineKnotsX,
                   self.ySplineKnotsY,
                   self.ySplineCoeff,
                   self.splineOrder,
                   self.splineOrder ],
            dx=0, dy=0).transpose()

        return yDispArray

    def array2spline(self, smoothing=1000, timing=False):
        """
        Calculates the spline coefficients from the displacements
        matrix using fitpack.

        @param smoothing: the greater the smoothing, the fewer the number of knots remaining
        @type smoothing: float
        @param timing: print the profiling of the calculation
        @type timing: bool
        """
        self.xmin = 0.0
        self.ymin = 0.0
        self.xmax = float(self.xDispArray.shape[0] - 1)
        self.ymax = float(self.yDispArray.shape[1] - 1)

        if timing:
            startTime = time.time()

        xRectBivariateSpline = scipy.interpolate.fitpack2.RectBivariateSpline(
            numpy.arange(self.xmax + 1.0),
            numpy.arange(self.ymax + 1),
            self.xDispArray.transpose(),
            s=smoothing)

        if timing:
            intermediateTime = time.time()

        yRectBivariateSpline = scipy.interpolate.fitpack2.RectBivariateSpline(
            numpy.arange(self.xmax + 1.0),
            numpy.arange(self.ymax + 1),
            self.yDispArray.transpose(),
            s=smoothing)

        if timing:
            logger.info("X-Displ evaluation= %.3f sec, Y-Displ evaluation=  %.3f sec."
                  % (intermediateTime - startTime, time.time() - intermediateTime))

        logger.info(len(xRectBivariateSpline.get_coeffs()),
              "x-coefs", xRectBivariateSpline.get_coeffs())
        logger.info(len(yRectBivariateSpline.get_coeffs()),
              "y-coefs", yRectBivariateSpline.get_coeffs())
        logger.info(len(xRectBivariateSpline.get_knots()[0]),
              len(xRectBivariateSpline.get_knots()[1]),
              "x-knots", xRectBivariateSpline.get_knots())
        logger.info(len(yRectBivariateSpline.get_knots()[0]),
              len(yRectBivariateSpline.get_knots()[1]),
              "y-knots", yRectBivariateSpline.get_knots())
        logger.info("Residual x,y", xRectBivariateSpline.get_residual(),
              yRectBivariateSpline.get_residual())
        self.xSplineKnotsX = xRectBivariateSpline.get_knots()[0]
        self.xSplineKnotsY = xRectBivariateSpline.get_knots()[1]
        self.xSplineCoeff = xRectBivariateSpline.get_coeffs()
        self.ySplineKnotsX = yRectBivariateSpline.get_knots()[0]
        self.ySplineKnotsY = yRectBivariateSpline.get_knots()[1]
        self.ySplineCoeff = yRectBivariateSpline.get_coeffs()

    def writeEDF(self, basename):
        """
        save the distortion matrices into a couple of files called
        basename-x.edf and basename-y.edf

        @param basename: base of the name used to save the data
        @type basename: str
        """
        try:
            from fabio.edfimage import edfimage
        except ImportError:
            logger.error("You will need the Fabio library available"
                  " from the Fable sourceforge")
            return
        self.spline2array()

        edfDispX = edfimage(data=self.xDispArray.astype("float32"), header={})
        edfDispY = edfimage(data=self.yDispArray.astype("float32"), header={})
        edfDispX.write(basename + "-x.edf", force_type="float32")
        edfDispY.write(basename + "-y.edf", force_type="float32")

    def write(self, filename):
        """
        save the cubic spline in an ascii file usable with Fit2D or
        SPD

        @param filename: name of the file containing the cubic spline distortion file
        @type filename: str
        """

        lst = ["SPATIAL DISTORTION SPLINE INTERPOLATION COEFFICIENTS",
               "",
               "  VALID REGION",
               "%14.7E%14.7E%14.7E%14.7E" % (self.xmin, self.ymin, self.xmax, self.ymax),
               "",
               "  GRID SPACING, X-PIXEL SIZE, Y-PIXEL SIZE",
               "%14.7E%14.7E%14.7E" % (self.grid, self.pixelSize[0], self.pixelSize[1]),
               "",
               "  X-DISTORTION",
               "%6i%6i" % (len(self.xSplineKnotsX), len(self.xSplineKnotsY))]
        txt = ""
        for i, val in enumerate(self.xSplineKnotsX):
            txt += "%14.7E" % val
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        for i, val in enumerate(self.xSplineKnotsY):
            txt += "%14.7E" % val
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        for i, val in enumerate(self.xSplineCoeff):
            txt += "%14.7E" % self.xSplineCoeff[i]
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        lst.append("")
        lst.append("  Y-DISTORTION\n%6i%6i" % (len(self.ySplineKnotsX),
                                               len(self.ySplineKnotsY)))
        for i, val in enumerate(self.ySplineKnotsX):
            txt += "%14.7E" % val
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        for i, val in enumerate(self.ySplineKnotsY):
            txt += "%14.7E" % val
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        for i, val in enumerate(self.ySplineCoeff):
            txt += "%14.7E" % val
            if i % 5 == 4:
                lst.append(txt)
                txt = ""
        if txt:
            lst.append(txt)
            txt = ""
        lst.append("")
        with open(filename, "w") as fil:
            fil.write("\n".join(lst))

    def tilt(self, center=(0.0, 0.0), tiltAngle=0.0, tiltPlanRot=0.0,
             distanceSampleDetector=1.0, timing=False):
        """
        The tilt method apply a virtual tilt on the detector, the
        point of tilt is given by the center

        @param center: position of the point of tilt, this point will not be moved.
        @type center: 2-tuple of floats
        @param tiltAngle: the value of the tilt in degrees
        @type tiltAngle: float in the range [-90:+90] degrees
        @param tiltPlanRot: the rotation of the tilt plan with the Ox axis (0 deg for y axis invariant, 90 deg for x axis invariant)
        @type tiltPlanRot: Float in the range [-180:180]
        @param distanceSampleDetector: the distance from sample to detector in meter (along the beam, so distance from sample to center)
        @type distanceSampleDetector: float

        @return: tilted Spline instance
        @rtype: Spline
        """
        if self.xDispArray is None:
            if self.filename is None:
                self.zeros()
            else:
                self.read(self.filename)
        logger.info("center=%s, tilt=%s, tiltPlanRot=%s, distanceSampleDetector=%sm, pixelSize=%sµm" % (center, tiltAngle, tiltPlanRot, distanceSampleDetector, self.pixelSize))
        if timing:
            startTime = time.time()
        distance = 1.0e6 * distanceSampleDetector  # from meters to microns
        cosb = numpy.cos(numpy.radians(tiltPlanRot))
        sinb = numpy.sin(numpy.radians(tiltPlanRot))
        cosf = numpy.cos(numpy.radians(tiltAngle))
        sinf = numpy.sin(numpy.radians(tiltAngle))

        # x and y are tilted in C/Fortran representation
        x = lambda i, j: j - center[0] - 0.5
        y = lambda i, j: i - center[1] - 0.5

        iPos = numpy.fromfunction(x,
                                  (int(self.ymax - self.ymin + 1),
                                   int(self.xmax - self.xmin + 1)))
        jPos = numpy.fromfunction(y,
                                  (int(self.ymax - self.ymin + 1),
                                   int(self.xmax - self.xmin + 1)))

        xPos = (iPos + self.xDispArray) * self.pixelSize[0]
        yPos = (jPos + self.yDispArray) * self.pixelSize[1]

        tiltArrayX = distance * (xPos * (cosf * cosb * cosb + sinb * sinb) + yPos * (cosf * cosb * sinb - cosb * sinb)) / \
            (distance + xPos * sinf * cosb + yPos * sinf * sinb) / self.pixelSize[0] - iPos
        tiltArrayY = distance * (xPos * (cosf * sinb * cosb - cosb * sinb) + yPos * (cosf * sinb * sinb + cosb * cosb)) / \
            (distance + xPos * sinf * cosb + yPos * sinf * sinb) / self.pixelSize[1] - jPos
        tiltedSpline = Spline()
        tiltedSpline.pixelSize = self.pixelSize
        tiltedSpline.grid = self.grid
        tiltedSpline.xDispArray = tiltArrayX
        tiltedSpline.yDispArray = tiltArrayY
        # tiltedSpline.array2spline(smoothing=1e-6, timing=True)
        if timing:
            logger.info("Time for the generation of the distorted spline: %.3f sec" % (time.time() - startTime))
        return tiltedSpline

    def setPixelSize(self, pixelSize):
        """
        Sets the size of the pixel from a 2-tuple of floats expressed
        in meters.

        @param: pixel size in meter
        @type pixelSize: 2-tuple of float
        """
        if len(pixelSize) == 2:
            self.pixelSize = (pixelSize[0] * 1.0e6, pixelSize[1] * 1.0e6)

    def getPixelSize(self):
        """
        Return the size of the pixel from as a 2-tuple of floats expressed
        in meters.

        @return: the size of the pixel from a 2D detector
        @rtype: 2-tuple of floats expressed in meter.

        """
        return (self.pixelSize[0] * 1.0e-6, self.pixelSize[1] * 1.0e-6)

    def bin(self, binning=None):
        """
        Performs the binning of a spline (same camera with different binning)

        @param binning: binning factor as integer or 2-tuple of integers
        @type: int or (int, int)

        """
        if "__len__" in dir(binning):
            binX, binY = float(binning[0]), float(binning[1])
        else:
            binX = binY = float(binning)
        self.xSplineKnotsX /= binX
        self.xSplineKnotsY /= binY
        self.ySplineKnotsX /= binX
        self.ySplineKnotsY /= binY
        self.pixelSize = (binX * self.pixelSize[0], binY * self.pixelSize[1])
        self.xmax = self.xmax / binX
        self.ymax = self.ymax / binY
        self.xSplineCoeff /= binX
        self.ySplineCoeff /= binY
        self.xDispArray = None
        self.yDispArray = None


    def correct(self, pos):
        delta1 = fitpack.bisplev(pos[1], pos[0],
                                        [self.xSplineKnotsX,
                                         self.xSplineKnotsY,
                                         self.xSplineCoeff,
                                         self.splineOrder,
                                         self.splineOrder],
                                 dx=0, dy=0)

        delta0 = fitpack.bisplev(pos[1], pos[0], [self.ySplineKnotsX,
                                         self.ySplineKnotsY,
                                         self.ySplineCoeff,
                                         self.splineOrder,
                                         self.splineOrder],
                                 dx=0, dy=0)
        return delta0 + pos[0], delta1 + pos[1]

def main():
    """
    Some tests ....
    """
    center = (1000, 1000)
    tilt = 10  # deg
    rotation_tilt = 0  # deg
    distance = 100  # mm
    spline_file = "example.spline"
    for keyword in sys.argv[1:]:
        if os.path.isfile(keyword):
            spline_file = keyword
        elif keyword.lower().find("center=") in [0, 1, 2]:
            center = map(float, keyword.split("=")[1].split("x"))
        elif keyword.lower().find("dist=") in [0, 1, 2]:
            distance = float(keyword.split("=")[1])
        elif keyword.lower().find("tilt=") in [0, 1, 2]:
            tilt = float(keyword.split("=")[1])
        elif keyword.lower().find("rot=") in [0, 1, 2]:
            rotation_tilt = float(keyword.split("=")[1])

    spline = Spline()
    spline.read(spline_file)
    logger.info("Original Spline: %s" % spline)
    spline.spline2array(timing=True)
    tilted = spline.tilt(center, tilt, rotation_tilt, distance, timing=True)
    tilted.writeEDF("%s-tilted-t%i-p%i-d%i" %
                    (os.path.splitext(spline_file)[0],
                     tilt, rotation_tilt, distance))

if __name__ == '__main__':
    main()