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Adds inline/xline range support to extract_trace_header_3d. Adds extract_xline_3d

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This commit is contained in:
Robert Smallshire
2015-06-14 17:20:29 +02:00
parent 9652730586
commit 2bee1e4f99
1 changed files with 140 additions and 18 deletions
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segpy-ext/segpy-numpy/segpy_numpy/extract.py
+140 -18
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@@ -13,15 +13,45 @@ class DimensionalityError:
# TODO: Add inline_numbers and xline_numbers arguments
def extract_trace_header_field_3d(reader, fields, null=None):
def extract_trace_header_field_3d(reader_3d, fields, inline_numbers=None, xline_numbers=None, null=None):
"""Extract a single trace header field from all trace headers as an array.
Args:
reader: A SegYReader3D
reader_3d: A SegYReader3D
fields: A an iterable series where each item is either the string name of a field
or an object with a 'name' attribute which is the name of a field, such as a
NamedField.
fields: A an iterable series where each item is either the name of a field as a string
or an object such as a NamedField with a 'name' attribute which in turn is the name
of a field as a string, such as a NamedField.
inline_numbers: The inline numbers for which traces are to be extracted.
This argument can be specified in three ways:
None (the default) - All traces within the each crossline will be be extracted.
sequence - When a sequence, such as a range or a list is provided only those traces at
inline numbers corresponding to the items in the sequence will be extracted. The
traces will always be extracted in increasing numeric order and duplicate entries
will be ignored. For example inline_numbers=range(100, 200, 2) will extract alternate
traces from inline number 100 to inline number 198 inclusive.
slice - When a slice object is provided the slice will be applied to the sequence of all
inline numbers. For example inline_numbers=slice(100, -100) will omit the first
one hundred and the last one hundred traces, irrespective of their numbers.
xline_numbers: The crossline numbers at which traces are to be extracted.
This argument can be specified in three ways:
None (the default) - All traces at within each inline will be be extracted.
sequence - When a sequence, such as a range or a list is provided only those traces at
crossline numbers corresponding to the items in the sequence will be extracted. The
traces will always be extracted in increasing numeric order and duplicate entries
will be ignored. For example xline_numbers=range(100, 200, 2) will extract alternate
traces from crossline number 100 to crossline number 198 inclusive.
slice - When a slice object is provided the slice will be applied to the sequence of all
crossline numbers. For example xline_numbers=slice(100, -100) will omit the first
one hundred and the last one hundred traces, irrespective of their numbers.
null: An optional null value for missing traces. The null value must be convertible
to all field value types.
@@ -37,14 +67,17 @@ def extract_trace_header_field_3d(reader, fields, null=None):
"""
field_names = [_extract_field_name(field) for field in fields]
inline_numbers = ensure_superset(reader_3d.inline_numbers(), inline_numbers)
xline_numbers = ensure_superset(reader_3d.xline_numbers(), xline_numbers)
shape = (len(inline_numbers), len(xline_numbers))
class SubHeader(metaclass=SubFormatMeta,
parent_format=reader.trace_header_format_class,
parent_format=reader_3d.trace_header_format_class,
parent_field_names=field_names):
pass
sub_header_packer = make_header_packer(SubHeader, reader.endian)
sub_header_packer = make_header_packer(SubHeader, reader_3d.endian)
TraceHeaderArrays = namedtuple('TraceHeaderArrays', field_names)
shape = (reader.num_inlines(), reader.num_xlines())
arrays = (_make_array(shape,
make_dtype(getattr(SubHeader, field_name).value_type.SEG_Y_TYPE),
@@ -53,16 +86,16 @@ def extract_trace_header_field_3d(reader, fields, null=None):
trace_header_arrays = TraceHeaderArrays(*arrays)
for inline_xline in reader.inline_xline_numbers():
inline_number, xline_number = inline_xline
trace_index = reader.trace_index(inline_xline)
trace_header = reader.trace_header(trace_index, sub_header_packer)
inline_index = reader.inline_numbers().index(inline_number)
xline_index = reader.xline_numbers().index(xline_number)
for inline_index, inline_number in enumerate(inline_numbers):
for xline_index, xline_number in enumerate(xline_numbers):
inline_xline_number = (inline_number, xline_number)
if reader_3d.has_trace_index(inline_xline_number):
trace_index = reader_3d.trace_index((inline_number, xline_number))
trace_header = reader_3d.trace_header(trace_index, sub_header_packer)
for field_name, a in zip(field_names, trace_header_arrays):
field_value = getattr(trace_header, field_name)
a[inline_index, xline_index] = field_value
for field_name, a in zip(field_names, trace_header_arrays):
field_value = getattr(trace_header, field_name)
a[inline_index, xline_index] = field_value
return trace_header_arrays
@@ -151,7 +184,7 @@ def extract_inline_3d(reader_3d, inline_number, xline_numbers=None, sample_numbe
a regular array will be returned. The first (slowest changing) index will correspond
to the traces (index zero will correspond to the first crossline number). The
second (fastest changing) index will correspond to the samples (index zero will
correspond to the first sample number.
correspond to the first sample number).
"""
if inline_number not in reader_3d.inline_numbers():
raise ValueError("Inline number {} not present in {}".format(inline_number, reader_3d))
@@ -195,6 +228,95 @@ def _populate_inline_array_over_sample_range(reader, inline_number, xline_number
array[xline_index, :] = trace_samples[source_slice]
def extract_xline_3d(reader_3d, xline_number, inline_numbers=None, sample_numbers=None, null=None):
"""Extract an inline as a two-dimensional array.
Args:
reader: A SegYReader3D object.
xline_number: The number of the xline to be extracted.
inline_numbers: The inline numbers within the crossline at which traces are to be extracted.
This argument can be specified in three ways:
None (the default) - All traces within the crossline will be be extracted.
sequence - When a sequence, such as a range or a list is provided only those traces at
inline numbers corresponding to the items in the sequence will be extracted. The
traces will always be extracted in increasing numeric order and duplicate entries
will be ignored. For example inline_numbers=range(100, 200, 2) will extract alternate
traces from inline number 100 to inline number 198 inclusive.
slice - When a slice object is provided the slice will be applied to the sequence of all
inline numbers. For example inline_numbers=slice(100, -100) will omit the first
one hundred and the last one hundred traces, irrespective of their numbers.
sample_numbers: The sample numbers within each trace at which samples are to be extracted.
This argument can be specified in three ways:
None (the default) - All samples within the trace will be be extracted.
sequence - When a sequence, such as a range or a list is provided only those samples at
sample numbers corresponding to the items in the sequence will be extracted. The
samples will always be extracted in increasing numeric order and duplicate entries
will be ignored. For example sample_numbers=range(100, 200, 2) will extract alternate
samples from sample number 100 to sample number 198 inclusive.
slice - When a slice object is provided the slice will be applied to the sequence of all
sample numbers. For example sample_numbers=slice(100, -100) will omit the first
one hundred and the last one hundred samples, irrespective of their numbers.
null: A null value. When None is specified as the null value a masked array will be returned.
Returns:
A two-dimensional array. If null is None a masked array will be returned, otherwise
a regular array will be returned. The first (slowest changing) index will correspond
to the traces (index zero will correspond to the first inline number). The
second (fastest changing) index will correspond to the samples (index zero will
correspond to the first sample number).
"""
if xline_number not in reader_3d.xline_numbers():
raise ValueError("Crossline number {} not present in {}".format(xline_number, reader_3d))
inline_numbers = ensure_superset(reader_3d.inline_numbers(), inline_numbers)
sample_numbers = ensure_superset(range(0, reader_3d.max_num_trace_samples()), sample_numbers)
shape = (len(inline_numbers), len(sample_numbers))
dtype = make_dtype(reader_3d.data_sample_format)
array = _make_array(shape, dtype, null)
if isinstance(sample_numbers, range):
_populate_xline_array_over_sample_range(reader_3d, xline_number, inline_numbers, sample_numbers, array)
else:
_populate_xline_array_numbered_samples(reader_3d, xline_number, inline_numbers, sample_numbers, array)
return array
def _populate_xline_array_numbered_samples(reader, xline_number, inline_numbers, sample_numbers, array):
for inline_index, inline_number in enumerate(inline_numbers):
inline_xline_number = (inline_number, xline_number)
if reader.has_trace_index(inline_xline_number):
trace_index = reader.trace_index(inline_xline_number)
num_trace_samples = reader.num_trace_samples(trace_index)
trace_sample_start = sample_numbers[0]
trace_sample_stop = min(sample_numbers[-1] + 1, num_trace_samples)
trace_samples = reader.trace_samples(trace_index, trace_sample_start, trace_sample_stop)
for sample_index, sample_number in enumerate(sample_numbers):
array[inline_index, sample_index] = trace_samples[sample_number - trace_sample_start]
def _populate_xline_array_over_sample_range(reader, xline_number, inline_numbers, sample_numbers, array):
for inline_index, inline_number in enumerate(inline_numbers):
inline_xline_number = (inline_number, xline_number)
if reader.has_trace_index(inline_xline_number):
trace_index = reader.trace_index(inline_xline_number)
num_trace_samples = reader.num_trace_samples(trace_index)
trace_sample_stop = min(sample_numbers.stop, num_trace_samples)
trace_samples = reader.trace_samples(trace_index, sample_numbers.start, trace_sample_stop)
source_slice = slice(sample_numbers.start, trace_sample_stop, sample_numbers.step)
array[inline_index, :] = trace_samples[source_slice]
def _make_array(shape, dtype, null=None):
"""Make an array"""
if null is None: