-
sfDataArray
-
This resource specifies a two-dimensional array containing the data
comprising a scalar field. There is no default for this resource, and
it must be specified in order to create a ScalarField
object successfully. The faster varying dimension (second dimension
in C or NCL, first dimension in Fortran) is assumed to align with the X or
horizontal axis of a rectangular coordinate system. However, you may
exchange the dimensions of the array by appropriately setting the
resource, sfExchangeDimensions. Although the
ScalarField object always converts the data into type
NhlTFloat before passing it along to ScalarField
receiver objects, it accepts data arrays containing data of any of the
following types:
- NhlTByte
- NhlTCharacter
- NhlTShort
- NhlTInteger
- NhlTLong
- NhlTFloat
- NhlTDouble
Default: NULL
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sfXArray
-
The values of the sfXArray resource sequentially represent
the X-Axis coordinate of each successive element along the
faster-varying dimension of the data array. If sfXArray is
set to a non-NULL value, ScalarField
checks to ensure first that it has the same number of elements as the
X-axis dimension of the data array and second that it is monotonically
increasing or descreasing. If the input array fails either of these
tests, sfXArray is reset to its default value of
NULL, and the data array is treated as if each element
were equally spaced along the X Axis between the values of
sfXCStartV and sfXCEndV. If the input array
is valid, ScalarField replaces the current value of
sfXCStartV with the value of the first element of
sfXArray, and sfXCEndV with the value of the last
element. You can specify sfXArray using a single-dimensioned
array of any of the types allowed for sfDataArray.
V4.1 Status Note 1
Default: NULL
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sfYArray
-
The values of the sfYArray resource sequentially represent
the Y-Axis coordinate of each successive element along the
slower-varying dimension of the data array. If sfYArray is
set to a non-NULL value, ScalarField
checks to ensure first that it has the same number of elements as the
Y-axis dimension of the data array and second that it is monotonically
increasing or descreasing. If the input array fails either of these
tests, sfYArray is reset to its default value of
NULL, and the data array is treated as if each element
were equally spaced along the Y Axis between the values of
sfYCStartV and sfYCEndV. If the input array
is valid, ScalarField replaces the current value of
sfYCStartV with the value of the first element of
sfYArray, and sfYCEndV with the value of the last
element. You can specify sfYArray using a single-dimensioned
array of any of the types allowed for sfDataArray.
V4.1 Status Note 1
Default: NULL
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sfCopyData
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The boolean resource sfCopyData allows you to control whether
the ScalarField object always copies the elements of
the sfDataArray into a private memory area. If you set
sfCopyData False, ScalarField will not copy
the sfXArray or the sfYArray data and will try to
avoid making a copy of the sfDataArray data. You are then
responsible for ensuring that the data memory locations for these
arrays are preserved intact for the lifetime of the
ScalarField. In return, you save some dynamic memory
space. Note that a number of circumstances require
ScalarField to copy the data regardless. These
include supplying data of any type other than NhlTFloat,
requesting that the data dimensions be exchanged, or setting a stride
value greater than 1 in either the X or the Y dimension. Also, if you
specify a data array subset and one or both of the coordinate array
resources (sfXArray and/or sfYArray) is
non-NULL, copies are made of the subsetted part of the
coordinate array.
Default: True
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sfExchangeDimensions
-
When this boolean resource is set True, ScalarField
exchanges the dimensions of the data array. Rows become columns and
columns become rows; the fast varying dimension becomes the slow varying
dimension and vice-versa. Whenever sfExchangeDimensions is True,
ScalarField must copy the data array, regardless of the
setting of the sfCopyData resource.
Default: False
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sfMissingValueV
-
If you set sfMissingValueV to a non-NULL value,
ScalarField treats occurrences of its value in the
data array as representing an undefined value. If left unset,
ScalarField assumes that all values in the data array
are valid. You may set sfMissingValueV using any of the data
types ScalarField accepts for the
sfDataArray resource.
Default: NULL
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sfDataMinV
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By default the ScalarField object sets
sfDataMinV to the smallest value in the data array. However,
if you set the value of this resource, ScalarField
does not process the array to find the minimum value. Instead it
assumes that the set value is, in fact, the minimum value. You may set
sfDataMinV using any of the data types
ScalarField accepts for the sfDataArray
resource.
Default: <dynamic>
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sfDataMaxV
-
By default the ScalarField object sets
sfDataMaxV to the largest value in the data array. However,
if you set the value of this resource, ScalarField
does not process the array to find the maximum value. Instead it
assumes that the set value is, in fact, the maximum value. You may set
sfDataMaxV using any of the data types
ScalarField accepts for the sfDataArray
resource.
Default: <dynamic>
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sfXCStartV
-
This resource specifies the location along the X Axis of the first
element of the faster-varying dimension of the data. If the array
resource sfXArray is set and found to be valid,
ScalarField overwrites the current value of
sfXCStartV, replacing it with the value of the first element
of sfXArray. Otherwise, you can set sfXCStartV to
any value (presumably meaningful in the context of the your data). If
sfXCStartV is greater than sfXCEndV, the direction
of the data locations along the X Axis is opposite the direction of
the positive X Axis. If sfXArray is NULL or
invalid and sfXCStartV is not specified,
ScalarField sets sfXCStartV to the value
0. You may set sfXCStartV using any of the data types
ScalarField accepts for the sfDataArray
resource.
Default: <dynamic>
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sfXCEndV
-
This resource specifies the location along the X Axis of the last
element of the faster-varying dimension of the data. If the array
resource sfXArray is set and found to be valid,
ScalarField overwrites the current value of
sfXCEndV, replacing it with the value of the last element of
sfXArray. Otherwise, you can set sfXCEndV to any
value (presumably meaningful in the context of the your data). If
sfXCStartV is greater than sfXCEndV, the direction
of the data locations along the X Axis is opposite the direction of
the positive X Axis. If sfXArray is NULL or
invalid and sfXCEndV is not specified,
ScalarField sets sfXCEndV to the size of the
faster-varying data dimension minus one. You may set sfXCEndV
using any of the data types ScalarField accepts for
the sfDataArray resource.
Default: <dynamic>
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sfYCStartV
-
This resource specifies the location along the Y Axis of the first
element of the slower-varying dimension of the data. If the array
resource sfYArray is set and found to be valid,
ScalarField overwrites the current value of
sfYCStartV, replacing it with the value of the first element
of sfYArray. Otherwise, you can set sfYCStartV to
any value (presumably meaningful in the context of the your data). If
sfYCStartV is greater than sfYCEndV, the direction
of the data locations along the Y Axis is opposite the direction of
the positive Y Axis. If sfYArray is NULL or
invalid and sfYCStartV is not specified,
ScalarField sets sfYCStartV to the value
0. You may set sfYCStartV using any of the data types
ScalarField accepts for the sfDataArray
resource.
Default: <dynamic>
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sfYCEndV
-
This resource specifies the location along the Y Axis of the last
element along the slower-varying dimension of the data. If the array
resource sfYArray is set and found to be valid,
ScalarField overwrites the current value of
sfYCStartV, replacing it with the value of the last element
of sfYArray. Otherwise, you can set sfYCStartV to
any value (presumably meaningful in the context of the your data). If
sfYCStartV is greater than sfYCEndV, the direction
of the data locations along the Y Axis is opposite the direction of
the positive Y Axis. If sfYArray is NULL or
invalid and sfYCEndV is not specified,
ScalarField sets sfYCEndV to the size of the
slower-varying data dimension minus one. You may set
sfYCEndV using any of the data types
ScalarField accepts for the sfDataArray
resource.
Default: <dynamic>
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sfXCStartSubsetV
-
sfXCStartSubsetV specifies the starting location along the
X Axis of a rectangular sub-array of the data array. It should be set
to a value within the data coordinate extent as established by the
values of sfXCStartV and sfXCEndV. If it is outside
the coordinate extent, ScalarField issues a warning
and sets it to the value of sfXCStartV. If the values of
sfXCStartSubsetV and sfXCEndSubsetV are oppositely
directed from the direction established by sfXCStartV and
sfXCEndV, ScalarField issues a warning and
exchanges their values. When you do not explicitly set a value for
sfXCStartSubsetV:
- at initialization or when the X-Axis dimension size changes,
if sfXCStartIndex is not set,
sfXCStartSubsetV takes the value of sfXCStartV;
- else if sfXCStartIndex is set, or there is a change to
sfXCStartV, sfXCEndV or sfXArray,
sfXCStartSubsetV takes the data coordinate value indexed by the
value of sfXCStartIndex;
- else sfXCStartSubsetV retains its current value.
Since the data array grid consists of data located at discrete
points, the location specified by sfXCStartSubsetV might well
fall between two data points. In this case,
ScalarField selects a beginning index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. Get the value of the read-only resource
sfXCActualStartF in order to find the exact start of the subset
along the X Axis. You may set sfXCSubsetStartV using any of the
data types that ScalarField accepts for the
sfDataArray resource.
Default: <dynamic>
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sfXCEndSubsetV
-
sfXCEndSubsetV specifies the ending location along the X Axis
of a rectangular sub-array of the data array. It should be set to a
value within the data coordinate extent as established by the values
of sfXCStartV and sfXCEndV. If it is outside the
coordinate extent, ScalarField issues a warning and
sets it to the value of sfXCEndV. If the values of
sfXCStartSubsetV and sfXCEndSubsetV are oppositely
directed from the direction established by sfXCStartV and
sfXCEndV, ScalarField issues a warning and
exchanges their values. When you do not explicitly set a value for
sfXCEndSubsetV:
- at initialization or when the X-Axis dimension size changes,
if sfXCEndIndex is not set,
sfXCEndSubsetV takes the value of sfXCEndV;
- else if sfXCEndIndex is set, or there is a change to
sfXCStartV, sfXCEndV or sfXArray,
sfXCEndSubsetV takes the data coordinate value indexed by the
value of sfXCEndIndex;
- else sfXCEndSubsetV retains its current value.
Since the data array grid consists of data located at discrete
points, the location specified by sfXCEndSubsetV might well
fall between two data points. In this case,
ScalarField selects an ending index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. Get the value of the read-only resource
sfXCActualEndF in order to find the exact end of the subset
along the X Axis. You may set sfXCSubsetEndV using any of the data
types that ScalarField accepts for the
sfDataArray resource.
Default: <dynamic>
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sfYCStartSubsetV
-
sfYCStartSubsetV specifies the starting location along the
Y Axis of a rectangular sub-array of the data array. It should be set
to a value within the data coordinate extent as established by the
values of sfYCStartV and sfYCEndV. If it is outside
the coordinate extent, ScalarField issues a warning
and sets it to the value of sfYCStartV. If the values of
sfYCStartSubsetV and sfYCEndSubsetV are oppositely
directed from the direction established by sfYCStartV and
sfYCEndV, ScalarField issues a warning and
exchanges their values. When you do not explicitly set a value for
sfYCStartSubsetV:
- at initialization or when the Y-Axis dimension size changes,
if sfYCStartIndex is also set,
sfYCStartSubsetV takes the value of sfYCStartV;
- else if sfYCStartIndex is set, or there is a change to
sfYCStartV, sfYCEndV or sfYArray,
sfYCStartSubsetV takes the data coordinate value indexed by the
value of sfYCStartIndex;
- else sfYCStartSubsetV retains its current value.
Since the data array grid consists of data located at discrete
points, the location specified by sfYCStartSubsetV might well
fall between two data points. In this case,
ScalarField selects a beginning index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. Get the value of the read-only resource
sfYCActualStartF in order to find the exact start of the subset
along the Y Axis. You may set sfYCSubsetStartV using any of the
data types that ScalarField accepts for the
sfDataArray resource.
Default: <dynamic>
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sfYCEndSubsetV
-
sfYCEndSubsetV specifies the ending location along the Y Axis
of a rectangular sub-array of the data array. It should be set to a
value within the data coordinate extent as established by the values
of sfYCStartV and sfYCEndV. If it is outside the
coordinate extent, ScalarField issues a warning and
sets it to the value of sfYCEndV. If the values of
sfYCStartSubsetV and sfYCEndSubsetV are oppositely
directed from the direction established by sfYCStartV and
sfYCEndV, ScalarField issues a warning and
exchanges their values. When you do not explicitly set a value for
sfYCEndSubsetV:
- at initialization or when the Y-Axis dimension size changes,
if sfYCEndIndex is not set,
sfYCEndSubsetV takes the value of sfYCEndV;
- else if sfYCEndIndex is set, or there is a change to
sfYCStartV, sfYCEndV or sfYArray,
sfYCEndSubsetV takes the data coordinate value indexed by the
value of sfYCEndIndex;
- else sfYCEndSubsetV retains its current value.
Since the data array grid consists of data located at discrete
points, the location specified by sfYCEndSubsetV might well
fall between two data points. In this case,
ScalarField selects an ending index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. Get the value of the read-only resource
sfYCActualEndF in order to find the exact end of the subset
along the Y Axis. You may set sfYCSubsetEndV using any of the data
types that ScalarField accepts for the
sfDataArray resource.
Default: <dynamic>
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sfXCStartIndex
-
This resource specifies the smaller of two indexes along the X-Axis
dimension bounding a rectangular sub-array of the data array.
Explicitly setting sfXCStartSubsetV overrides any value set
for sfXCStartIndex and causes it to be set to the array
index value associated with the closest data point such that the
requested data coordinate location is included within the
subset. Otherwise, when you set sfXCStartIndex, the data
coordinate value indexed by its value is placed into
sfXCStartSubsetV. sfXCStartIndex retains its value
when the data array changes, unless the X-Axis dimension size also
changes. In this case, assuming neither sfXCStartSubsetV nor
sfXCStartIndex is explicitly set at the same time,
sfXCStartIndex is set to 0.
Default: <dynamic>
-
sfXCEndIndex
-
This resource specifies the larger of two indexes along the X-Axis
dimension bounding a rectangular sub-array of the data array.
Explicitly setting sfXCEndSubsetV overrides any value set
for sfXCEndIndex and causes it to be set to the array
index value associated with the closest data point such that the
requested data coordinate location is included within the
subset. Otherwise, when you set sfXCEndIndex, the data
coordinate value indexed by its value is placed into
sfXCEndSubsetV. sfXCEndIndex retains its value
when the data array changes, unless the X-Axis dimension size also
changes. In this case, assuming neither sfXCEndSubsetV nor
sfXCEndIndex is explicitly set at the same time,
sfXCEndIndex is set to the size of the X-Axis dimension minus one.
Default: <dynamic>
-
-
sfYCStartIndex
-
This resource specifies the smaller of two indexes along the Y-Axis
dimension bounding a rectangular sub-array of the data array.
Explicitly setting sfYCStartSubsetV overrides any value set
for sfYCStartIndex, and causes it to be set to the array
index value associated with the closest data point such that the
requested data coordinate location is included within the
subset. Otherwise, when you set sfYCStartIndex, the data
coordinate value indexed by its value is placed into
sfYCStartSubsetV. sfYCStartIndex retains its value
when the data array changes, unless the Y-Axis dimension size also
changes. In this case, assuming neither sfYCStartSubsetV nor
sfYCStartIndex is explicitly set at the same time,
sfYCStartIndex is set to 0.
Default: <dynamic>
-
sfYCEndIndex
-
This resource specifies the larger of two indexes along the Y-Axis
dimension bounding a rectangular sub-array of the data array.
Explicitly setting sfYCEndSubsetV overrides any value set
for sfYCEndIndex, and causes it to be set to the array
index value associated with the closest data point such that the
requested data coordinate location is included within the
subset. Otherwise, when you set sfYCEndIndex, the data
coordinate value indexed by its value is placed into
sfYCEndSubsetV. sfYCEndIndex retains its value
when the data array changes, unless the Y-Axis dimension size also
changes. In this case, assuming neither sfYCEndSubsetV nor
sfYCEndIndex is explicitly set at the same time,
sfYCEndIndex is set to the size of the Y-Axis dimension minus one.
Default: <dynamic>
-
sfXCActualStartF
-
When a subset of the data is specified by location in data
coordinate space using sfXCStartSubsetV, this location might
well fall between two data points. In this case,
ScalarField selects a beginning index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. The read-only resource sfXCActualStartF always
contains the actual starting location of the data subset along the
X Axis.
Default: <dynamic>
-
sfXCActualEndF
-
When a subset of the data is specified by location in data
coordinate space using sfXCEndSubsetV, this location might
well fall between two data points. In this case,
ScalarField selects an ending index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. The read-only resource sfXCActualEndF always
contains the actual ending location of the data subset along the
X Axis.
Default: <dynamic>
-
sfYCActualStartF
-
When a subset of the data is specified by location in data
coordinate space using sfYCStartSubsetV, this location might
well fall between two data points. In this case,
ScalarField selects a beginning index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. The read-only resource sfYCActualStartF always
contains the actual starting location of the data subset along the
Y Axis.
Default: <dynamic>
-
sfYCActualEndF
-
When a subset of the data is specified by location in data
coordinate space using sfYCEndSubsetV, this location might
well fall between two data points. In this case,
ScalarField selects an ending index for the array
subset such that the requested location is included within the
subset. Thus the subset array, as delivered to the receiving object,
may represent a slightly larger area of the data coordinate space than
requested. The read-only resource sfYCActualEndF always
contains the actual ending location of the data subset along the
Y Axis.
Default: <dynamic>
-
sfXCStride
-
When sfXCStride has a value greater than one, the
ScalarField object creates a new array containing
only columns indexed along the X dimension by successive multiples
(starting with 0) of the sfXCStride value added to the
starting index. The starting index is based on the current state of
the applicable subsetting resources; it is 0 if no array subsetting is
in effect. The resulting array is passed to the receiving plot object.
Note that if ending index minus starting index is not an exact multiple
of the sfXCStride value, then the data coordinate range may be
reduced slightly.
Default: 1
-
sfYCStride
-
When sfYCStride has a value greater than one, the
ScalarField object creates a new array containing
only rows indexed along the Y dimension by successive multiples
(starting with 0) of the sfYCStride value added to the
starting index. The starting index is based on the current state of
the applicable subsetting resources; it is 0 if no array subsetting is in
effect. The resulting array is passed to the receiving plot object.
Note that if ending index minus starting index is not an exact multiple
of the sfYCStride value, then the data coordinate range may be
reduced slightly.
Default: 1
