Python numpy.ma() 使用实例

The following are code examples for showing how to use . They are extracted from open source Python projects. You can vote up the examples you like or vote down the exmaples you don’t like. You can also save this page to your account.

Example 1

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 2

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 3

def fn_getma(fn, bnum=1):
    """Get masked array from input filename

    Parameters
    ----------
    fn : str
        Input filename string
    bnum : int, optional
        Band number
    
    Returns
    -------
    np.ma.array    
        Masked array containing raster values
    """
    #Add check for filename existence
    ds = fn_getds(fn)
    return ds_getma(ds, bnum=bnum)

#Given input dataset, return a masked array for the input band 

Example 4

def ds_getma(ds, bnum=1):
    """Get masked array from input GDAL Dataset

    Parameters
    ----------
    ds : gdal.Dataset 
        Input GDAL Datset
    bnum : int, optional
        Band number
    
    Returns
    -------
    np.ma.array    
        Masked array containing raster values
    """
    b = ds.GetRasterBand(bnum)
    return b_getma(b)

#Given input band, return a masked array 

Example 5

def b_getma(b):
    """Get masked array from input GDAL Band

    Parameters
    ----------
    b : gdal.Band 
        Input GDAL Band 
    
    Returns
    -------
    np.ma.array    
        Masked array containing raster values
    """
    b_ndv = get_ndv_b(b)
    #bma = np.ma.masked_equal(b.ReadAsArray(), b_ndv)
    #This is more appropriate for float, handles precision issues
    bma = np.ma.masked_values(b.ReadAsArray(), b_ndv)
    return bma 

Example 6

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 7

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 8

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 9

def test_testPut(self):
        # Test of put
        with suppress_warnings() as sup:
            sup.filter(
                np.ma.core.MaskedArrayFutureWarning,
                "setting an item on a masked array which has a "
                "shared mask will not copy")
            d = arange(5)
            n = [0, 0, 0, 1, 1]
            m = make_mask(n)
            x = array(d, mask=m)
            self.assertTrue(x[3] is masked)
            self.assertTrue(x[4] is masked)
            x[[1, 4]] = [10, 40]
            self.assertTrue(x.mask is not m)
            self.assertTrue(x[3] is masked)
            self.assertTrue(x[4] is not masked)
            self.assertTrue(eq(x, [0, 10, 2, -1, 40]))

            x = array(d, mask=m)
            x.put([0, 1, 2], [-1, 100, 200])
            self.assertTrue(eq(x, [-1, 100, 200, 0, 0]))
            self.assertTrue(x[3] is masked)
            self.assertTrue(x[4] is masked) 

Example 10

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 11

def timer(s, v='', nloop=500, nrep=3):
    units = ["s", "ms", "µs", "ns"]
    scaling = [1, 1e3, 1e6, 1e9]
    print("%s : %-50s : " % (v, s), end=' ')
    varnames = ["%ss,nm%ss,%sl,nm%sl" % tuple(x*4) for x in 'xyz']
    setup = 'from __main__ import numpy, ma, %s' % ','.join(varnames)
    Timer = timeit.Timer(stmt=s, setup=setup)
    best = min(Timer.repeat(nrep, nloop)) / nloop
    if best > 0.0:
        order = min(-int(numpy.floor(numpy.log10(best)) // 3), 3)
    else:
        order = 3
    print("%d loops, best of %d: %.*g %s per loop" % (nloop, nrep,
                                                      3,
                                                      best * scaling[order],
                                                      units[order])) 

Example 12

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 13

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  'floor', 'ceil',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 14

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 15

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 16

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 17

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  'floor', 'ceil',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 18

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 19

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 20

def ds_getma_sub(src_ds, bnum=1, scale=None, maxdim=1024.):    
    """Load a subsampled array, rather than full resolution

    This is useful when working with large rasters

    Uses buf_xsize and buf_ysize options from GDAL ReadAsArray method.

    Parameters
    ----------
    ds : gdal.Dataset 
        Input GDAL Datset
    bnum : int, optional
        Band number
    scale : int, optional
        Scaling factor
    maxdim : int, optional 
        Maximum dimension along either axis, in pixels
    
    Returns
    -------
    np.ma.array    
        Masked array containing raster values
    """
    #print src_ds.GetFileList()[0]
    b = src_ds.GetRasterBand(bnum)
    b_ndv = get_ndv_b(b)
    ns, nl = get_sub_dim(src_ds, scale, maxdim)
    #The buf_size parameters determine the final array dimensions
    b_array = b.ReadAsArray(buf_xsize=ns, buf_ysize=nl)
    bma = np.ma.masked_values(b_array, b_ndv)
    return bma

#Note: need to consolidate with warplib.writeout (takes ds, not ma)
#Add option to build overviews when writing GTiff
#Input proj must be WKT 

Example 21

def replace_ndv(b, new_ndv):
    b_ndv = get_ndv_b(b)    
    bma = np.ma.masked_values(b.ReadAsArray(), b_ndv)
    bma.set_fill_value(new_ndv)
    b.WriteArray(bma.filled())
    b.SetNoDataValue(new_ndv)
    return b 

Example 22

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 23

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  # 'nonzero', 'around',
                  'floor', 'ceil',
                  # 'sometrue', 'alltrue',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 24

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 25

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 26

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 27

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  # 'nonzero', 'around',
                  'floor', 'ceil',
                  # 'sometrue', 'alltrue',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 28

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 29

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 30

def _get_stblock(self, data_input, hnd, mdlt, start_frame=None):
		goodness = False
		if start_frame is None:
				start_frame = random.randint(0, len(data_input['min_length'])-self.step*(self.nframes-1)-1)
		stblock = numpy.zeros([self.nframes, self.block_size, self.block_size])
		for ii in xrange(self.nframes):
				v = data_input[hnd][mdlt][start_frame + ii * self.step]
				mm = abs(numpy.ma.maximum(v))
				if mm > 0.:
						# normalize to zero mean, unit variance,
						# concatenate in spatio-temporal blocks
						stblock[ii] = self.prenormalize(v)
						goodness = True
		return stblock, goodness 

Example 31

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 32

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  'floor', 'ceil',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 33

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 34

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 35

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 36

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  'floor', 'ceil',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 37

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 38

def compare_functions_2v(func, nloop=500, test=True,
                       xs=xs, nmxs=nmxs,
                       ys=ys, nmys=nmys,
                       xl=xl, nmxl=nmxl,
                       yl=yl, nmyl=nmyl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs,nmys"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl,nmyl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 39

def test_testMixedArithmetic(self):
        na = np.array([1])
        ma = array([1])
        self.assertTrue(isinstance(na + ma, MaskedArray))
        self.assertTrue(isinstance(ma + na, MaskedArray)) 

Example 40

def test_testUfuncRegression(self):
        f_invalid_ignore = [
            'sqrt', 'arctanh', 'arcsin', 'arccos',
            'arccosh', 'arctanh', 'log', 'log10', 'divide',
            'true_divide', 'floor_divide', 'remainder', 'fmod']
        for f in ['sqrt', 'log', 'log10', 'exp', 'conjugate',
                  'sin', 'cos', 'tan',
                  'arcsin', 'arccos', 'arctan',
                  'sinh', 'cosh', 'tanh',
                  'arcsinh',
                  'arccosh',
                  'arctanh',
                  'absolute', 'fabs', 'negative',
                  'floor', 'ceil',
                  'logical_not',
                  'add', 'subtract', 'multiply',
                  'divide', 'true_divide', 'floor_divide',
                  'remainder', 'fmod', 'hypot', 'arctan2',
                  'equal', 'not_equal', 'less_equal', 'greater_equal',
                  'less', 'greater',
                  'logical_and', 'logical_or', 'logical_xor']:
            try:
                uf = getattr(umath, f)
            except AttributeError:
                uf = getattr(fromnumeric, f)
            mf = getattr(np.ma, f)
            args = self.d[:uf.nin]
            with np.errstate():
                if f in f_invalid_ignore:
                    np.seterr(invalid='ignore')
                if f in ['arctanh', 'log', 'log10']:
                    np.seterr(divide='ignore')
                ur = uf(*args)
                mr = mf(*args)
            self.assertTrue(eq(ur.filled(0), mr.filled(0), f))
            self.assertTrue(eqmask(ur.mask, mr.mask)) 

Example 41

def compare_functions_1v(func, nloop=500,
                       xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    funcname = func.__name__
    print("-"*50)
    print("%s on small arrays" % funcname)
    module, data = "numpy.ma", "nmxs"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)

    print("%s on large arrays" % funcname)
    module, data = "numpy.ma", "nmxl"
    timer("%(module)s.%(funcname)s(%(data)s)" % locals(), v="%11s" % module, nloop=nloop)
    return 

Example 42

def compare_methods(methodname, args, vars='x', nloop=500, test=True,
                    xs=xs, nmxs=nmxs, xl=xl, nmxl=nmxl):
    print("-"*50)
    print("%s on small arrays" % methodname)
    data, ver = "nm%ss" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)

    print("%s on large arrays" % methodname)
    data, ver = "nm%sl" % vars, 'numpy.ma'
    timer("%(data)s.%(methodname)s(%(args)s)" % locals(), v=ver, nloop=nloop)
    return 

Example 43

def test_testCopySize(self):
        # Tests of some subtle points of copying and sizing.
        with suppress_warnings() as sup:
            sup.filter(
                np.ma.core.MaskedArrayFutureWarning,
                "setting an item on a masked array which has a "
                "shared mask will not copy")

            n = [0, 0, 1, 0, 0]
            m = make_mask(n)
            m2 = make_mask(m)
            self.assertTrue(m is m2)
            m3 = make_mask(m, copy=1)
            self.assertTrue(m is not m3)

            x1 = np.arange(5)
            y1 = array(x1, mask=m)
            self.assertTrue(y1._data is not x1)
            self.assertTrue(allequal(x1, y1._data))
            self.assertTrue(y1.mask is m)

            y1a = array(y1, copy=0)
            self.assertTrue(y1a.mask is y1.mask)

            y2 = array(x1, mask=m, copy=0)
            self.assertTrue(y2.mask is m)
            self.assertTrue(y2[2] is masked)
            y2[2] = 9
            self.assertTrue(y2[2] is not masked)
            self.assertTrue(y2.mask is not m)
            self.assertTrue(allequal(y2.mask, 0))

            y3 = array(x1 * 1.0, mask=m)
            self.assertTrue(filled(y3).dtype is (x1 * 1.0).dtype)

            x4 = arange(4)
            x4[2] = masked
            y4 = resize(x4, (8,))
            self.assertTrue(eq(concatenate([x4, x4]), y4))
            self.assertTrue(eq(getmask(y4), [0, 0, 1, 0, 0, 0, 1, 0]))
            y5 = repeat(x4, (2, 2, 2, 2), axis=0)
            self.assertTrue(eq(y5, [0, 0, 1, 1, 2, 2, 3, 3]))
            y6 = repeat(x4, 2, axis=0)
            self.assertTrue(eq(y5, y6)) 

Example 44

def composite(reducers, *rasters, normalize='sum', nodata=-9999.0, dtype=np.float32):
    '''
    NOTE: Uses masked arrays in NumPy and therefore is MUCH slower than the
    `composite2()` function, which is equivalent in output.

    Creates a multi-image (multi-date) composite from input rasters. The
    reducers argument specifies, in the order of the bands (endmembers), how
    to pick a value for that band in each pixel. If None is given, then the
    median value of that band from across the images is used for that pixel
    value. If None is specified as a reducer, the corresponding band(s) will
    be dropped. Combining None reducer(s) with a normalized sum effectively
    subtracts an endmember under the unity constraint. Arguments:
        reducers    One of ('min', 'max', 'mean', 'median', None) for each endmember
        rasters     One or more raster files to composite
        normalize   True (by default) to normalize results by their sum
        nodata      The NoData value (defaults to -9999)
        dtype       The data type to coerce in the output array; very important if the desired output is float but NoData value is integer
    '''
    shp = rasters[0].shape
    num_non_null_bands = shp[0] - len([b for b in reducers if b is None])
    assert all(map(lambda x: x == shp, [r.shape for r in rasters])), 'Rasters must have the same shape'
    assert len(reducers) == shp[0], 'Must provide a reducer for each band (including None to drop the band)'

    # Swap the sequence of rasters for a sequence of bands, then collapse the X-Y axes
    stack = np.array(rasters).swapaxes(0, 1).reshape(shp[0], len(rasters), shp[-1]*shp[-2])

    # Mask out NoData values
    stack_masked = np.ma.masked_where(stack == nodata, stack)

    # For each band (or endmember)...
    band_arrays = []
    for i in range(shp[0]):
        if reducers[i] in ('min', 'max', 'median', 'mean'):
            band_arrays.append(getattr(np.ma, reducers[i])(stack_masked[i, ...], axis=0))

    # Stack each reduced band (and reshape to multi-band image)
    final_stack = np.ma.vstack(band_arrays).reshape((num_non_null_bands, shp[-2], shp[-1]))

    # Calculate a normalized sum (e.g., fractions must sum to one)
    if normalize is not None:
        constant = getattr(final_stack, normalize)(axis=0) # The sum across the bands
        constant.set_fill_value(1.0) # NaNs will be divided by 1.0
        constant = np.ma.repeat(constant, num_non_null_bands, axis=0).reshape(final_stack.shape)
        # Divide the values in each band by the normalized sum across the bands
        if num_non_null_bands > 1:
            final_stack = final_stack / constant.swapaxes(0, 1)

        else:
            final_stack = final_stack / constant

    # NOTE: Essential to cast type, e.g., to float in case first pixel (i.e. top-left) is all NoData of an integer type
    final_stack.set_fill_value(dtype(nodata)) # Fill NoData for NaNs

    return final_stack.filled() 
点赞

发表评论

电子邮件地址不会被公开。 必填项已用*标注