Example #1
0
def PBackFFT(FFTrev, inArray, outArray, err):
    """
    Back transform half plane complex to real
    
    inArray is FFTed (half plane complex - real) to outArray

    * FFTref   = FFT object to FT inArray
    * inArray  = CArray with image to be FFTed
      must be a size compatable with FFTrev
    * outArray = FArray for output
      must be a size compatable with FT of inArray
    * err      = Python Obit Error/message stack
    """
    ################################################################
    # Checks
    if not FFT.PIsA(FFTrev):
        print("Actually ",FFTrev.__class__)
        raise TypeError("FFTrev MUST be a Python Obit FFT")
    if not CArray.PIsA(inArray ):
        print("Actually ",inArray.__class__)
        raise TypeError("inArray MUST be a Python Obit CArray")
    if not FArray.PIsA(outArray ):
        print("Actually ",outArray.__class__)
        raise TypeError("outArray MUST be a Python Obit FArray")
    if not OErr.OErrIsA(err):
        raise TypeError("err MUST be an OErr")
    #
    # FFT
    PFFTC2R (FFTrev, inArray, outArray)

    FArray.PCenter2D (outArray)
Example #2
0
def PMakeBeamMask(inImage, inFFT, err):
    """
    Make uv plane weighting array
    
    Creates an FArray the size of a plane in inImage, FFT,
    takes real part and normalizes the central value to one
    Resulting array is returned.

    * inImage  = Python Image whose FArray is to be converted to a weight mask
    * inFFT    = Python Obit fortward FFT object
    * err      = Python Obit Error/message stack
    """
    ################################################################
    # Checks
    if not Image.PIsA(inImage):
        print "Actually ", inImage.__class__
        raise TypeError, "inImage MUST be a Python Obit Image"
    if not FFT.PIsA(inFFT):
        print "Actually ", inFFT.__class__
        raise TypeError, "inFFT MUST be a Python Obit FFT"
    #
    # Make copy of data array
    inArray = inImage.FArray
    outArray = FArray.PClone(inArray, err)
    #OErr.printErrMsg(err, "Error duplicating FArray for "+Image.PGetName(inImage))

    # Add model
    PCreateModel(inImage, outArray)

    # Pad for FFT
    FFTdim = FFT.PGetDim(inFFT)
    FFTArray = FArray.PClone(inArray, err)
    naxis = FFTdim[0:2]  # Make output big enough for FFT
    FFTArray = FArray.FArray("FFT array", naxis)
    PPadArray(inFFT, outArray, FFTArray)
    del outArray  # Cleanup

    # Swaparoonie
    FArray.PCenter2D(FFTArray)

    # FFT
    uvArray = PCreateFFTArray(inFFT)
    PFFTR2C(inFFT, FFTArray, uvArray)
    del FFTArray  # Cleanup

    # Extract Real part
    naxis = CArray.PGetNaxis(uvArray)[0:2]
    maskArray = FArray.FArray("Mask array for " + Image.PGetName(inImage),
                              naxis)
    CArray.PReal(uvArray, maskArray)
    del uvArray  # Cleanup

    # Normalize
    pos = [0, 1 + naxis[1] / 2]
    peak = FArray.PMax(maskArray, pos)
    norm = 1.0 / peak
    FArray.PSMul(maskArray, norm)

    return maskArray
Example #3
0
def PAccumImage(FFTfor, inImage, wtArray, accArray, workArray, err):
    """
    Accumulate the weighted FT of an FArray
    
    inImage is FFTed, multiplied by wtArray and accumulated into accArray

    * FFTfor   = FFT object to FT inArray
    * inImage  = Image to be accumulated
      must be a size compatable with FFTfor
      returned with contents swapped for FFTs
    * wtArray  = FArray containing accumulation weights
      must be a size compatable with FT of inArray
    * accArray = CArray in which the results are to be accumulated
      must be a size compatable with FT of inArray
    * workArray= CArray for temporary storage of FT of inArray
    * err      = Python Obit Error/message stack
    """
    ################################################################
    # Checks
    if not FFT.PIsA(FFTfor):
        print("Actually ",FFTfor.__class__)
        raise TypeError("FFTfor MUST be a Python Obit FFT")
    if not Image.PIsA(inImage ):
        print("Actually ",inImage.__class__)
        raise TypeError(" inImage MUST be a Python Obit Image")
    if not FArray.PIsA(wtArray):
        print("Actually ",wtArray.__class__)
        raise TypeError("wtArray MUST be a Python Obit FArray")
    if not CArray.PIsA(accArray):
        print("Actually ",accArray.__class__)
        raise TypeError("accArray MUST be a Python Obit CArray")
    if not CArray.PIsA(workArray):
        print("Actually ",workArray.__class__)
        raise TypeError("workArray MUST be a Python Obit CArray")
    if not OErr.OErrIsA(err):
        raise TypeError("err MUST be an OErr")
    #
    # Check compatability
    if not CArray.PIsCompatable (accArray, workArray):
        raise TypeError("accArray and workArray incompatible")

    # Get array from image
    inArray = Image.PGetFArray(inImage)

    # Swaparoonie
    FArray.PCenter2D (inArray)
    
    # FFT
    PFFTR2C (FFTfor, inArray, workArray)

    # Multiply by weights
    CArray.PFMul(workArray, wtArray, workArray)

    # Scale by inverse of beam area to get units the same
    # Get image info from descriptor
    desc     = inImage.Desc
    descDict = desc.Dict
    beamMaj = 3600.0 * descDict["beamMaj"]
    beamMin = 3600.0 * descDict["beamMin"]
    cdelt   = descDict["cdelt"]
    factor = (abs(cdelt[1])/beamMaj) * (abs(cdelt[1])/beamMin)
    CArray.PSMul(workArray, factor)

    # Accumulate
    CArray.PAdd(accArray, workArray, accArray)
Example #4
0
def PImageFFT(inImage, outAImage, outPImage, err):
    """
    FFTs an Image
    
    FFT inImage and write as real and imaginary as full plane (hermetian) 

    * inImage   = input Obit Python Image 1
      Any BLC and/or TRC set will be honored
    * outAImage = output Obit Python Amplitude image of FFT
      must be defined but not instantiated
    * outPImage = output Obit Python Phase (deg) image of FFT
      must be defined but not instantiated
    * err       = Python Obit Error/message stack
    """
    ################################################################
    # Checks
    if not Image.PIsA(inImage):
        raise TypeError("inImage MUST be a Python Obit Image")
    if not Image.PIsA(outAImage):
        raise TypeError("outAImage MUST be a Python Obit Image")
    if not Image.PIsA(outPImage):
        raise TypeError("outPImage MUST be a Python Obit Image")
    if not err.IsA():
        raise TypeError("err MUST be an OErr")
    #
    # Clone output images
    inImage.Clone(outAImage, err)
    inImage.Clone(outPImage, err)
    OErr.printErrMsg(err, "Error initializing images")

    # Size of FFT
    inImage.Open(Image.READONLY, err)
    inImage.Read(err)
    OErr.printErrMsg(err, "Error reading input")
    inHead = inImage.Desc.Dict
    FFTdim = [
        FFT.PSuggestSize(inHead["inaxes"][0]),
        FFT.PSuggestSize(inHead["inaxes"][1])
    ]

    # Create float arrays for FFT size
    inFArray = FArray.FArray("inF", naxis=FFTdim)
    outFArray = FArray.FArray("outF", naxis=FFTdim)

    # Create FFT for full complex FFT
    FFTfor = FFT.FFT("FFT", 1, 1, 2, FFTdim)

    # Create complex arrays for FFT size
    inCArray = CArray.CArray("inC", naxis=FFTdim)
    outCArray = CArray.CArray("outC", naxis=FFTdim)

    #Loop over planes
    nplane = inImage.Desc.Dict['inaxes'][2]
    for iax in range(1, nplane + 1):
        inImage.GetPlane(None, [iax, 1, 1, 1, 1], err)
        OErr.printErrMsg(err, "Error reading input")
        # Pad input into work FArray
        FArray.PPad(inImage.FArray, inFArray, 1.0)
        # and God said "The center of an FFT will be at the corners"
        FArray.PCenter2D(inFArray)
        # Zero output FArray and use as imaginary part
        FArray.PFill(outFArray, 0.0)
        # Copy input to scratch CArray
        CArray.PComplex(inFArray, outFArray, inCArray)

        # FFT
        FFT.PC2C(FFTfor, inCArray, outCArray)

        # Extract amplitude, write
        CArray.PAmp(outCArray, outFArray)
        # and God said "The center of an FFT will be at the corners"
        FArray.PCenter2D(outFArray)
        outAImage.FArray = FeatherUtil.PExtract(FFTfor, outFArray,
                                                outAImage.FArray, err)
        OErr.printErrMsg(err, "Error extracting output amplitude plane")
        outAImage.PutPlane(outAImage.FArray, [iax, 1, 1, 1, 1], err)

        # Extract phase, write
        CArray.PPhase(outCArray, outFArray)
        # To degrees
        FArray.PSMul(outFArray, 57.2956)
        # and God said "The center of an FFT will be at the corners"
        FArray.PCenter2D(outFArray)
        outPImage.FArray = FeatherUtil.PExtract(FFTfor, outFArray,
                                                outPImage.FArray, err)
        OErr.printErrMsg(err, "Error extracting output phase plane")
        outPImage.PutPlane(outPImage.FArray, [iax, 1, 1, 1, 1], err)
        # Error?
        OErr.printErrMsg(err, "Error writing output phase image")
        # end loop over planes

    # Fix headers
    outAImage.Open(Image.READWRITE, err)
    FFTHeaderUpdate(outAImage, FFTdim, err)
    outAImage.Close(err)
    OErr.printErrMsg(err, "Error writing output amplitude image")

    outPImage.Open(Image.READWRITE, err)
    FFTHeaderUpdate(outPImage, FFTdim, err)
    outPImage.Close(err)
    OErr.printErrMsg(err, "Error writing output phase image")

    # get any BLC, TRC for history
    info = inImage.List.Dict
    blc = [1, 1, 1, 1, 1, 1, 1]
    if 'BLC' in info:
        blc = info["BLC"][2]
    trc = [0, 0, 0, 0, 0, 0, 0]
    if 'TRC' in info:
        trc = info["TRC"][2]

    # Write history
    i = 0
    imtype = ("Amplitude", "Phase")
    for outImage in (outAImage, outPImage):
        inHistory = History.History("history", inImage.List, err)
        outHistory = History.History("history", outImage.List, err)
        # Copy History
        # FITS? - copy header
        if ("FileType" in info) and (info["FileType"][2][0] == 0):
            History.PCopyHeader(inHistory, outHistory, err)
        #Not needed History.PCopy(inHistory, outHistory, err)
        # Add this programs history
        outHistory.Open(History.READWRITE, err)
        outHistory.TimeStamp(" Start Obit PImageFFT", err)
        outHistory.TimeStamp(OSystem.PGetPgmName() + " BLC = " + str(blc), err)
        outHistory.TimeStamp(OSystem.PGetPgmName() + " TRC = " + str(trc), err)
        outHistory.TimeStamp(OSystem.PGetPgmName() + " type = " + imtype[i],
                             err)
        i += 1
        outHistory.Close(err)
Example #5
0
# Size of FFT
inImage.Open(Image.READONLY, err)
inImage.Read(err)
OErr.printErrMsg(err, "Error reading input")
inHead = inImage.Desc.Dict
FFTdim = [FFT.PSuggestSize(inHead["inaxes"][0]), FFT.PSuggestSize(inHead["inaxes"][1])]

# Create float arrays for FFT size
inFArray  = FArray.FArray("inF", naxis=FFTdim)
outFArray = FArray.FArray("outF", naxis=FFTdim)

# Pad input into work FArray
FArray.PPad(inImage.FArray, inFArray, 1.0)
# and God said "The center of an FFT will be at the corners"
FArray.PCenter2D(inFArray)
# Zero output FArray and use as imaginary part
FArray.PFill(outFArray, 0.0)

# Create FFT for full complex FFT
FFTfor = FFT.FFT("FFT", 1, 1, 2, FFTdim)

# Create complex arrays for FFT size
inCArray  = CArray.CArray("inC", naxis=FFTdim)
outCArray = CArray.CArray("outC", naxis=FFTdim)

# Copy input to scratch CArray
CArray.PComplex(inFArray, outFArray, inCArray)

# FFT
FFT.PC2C(FFTfor, inCArray, outCArray)