Transformation, IrregularTransformation, LogLinTransformation (tr) Resources
 trGridType (Transformation)

This resource of type NhlTGridType directly correlates with
the Transformation subclass used to map a plot
object's data into its coordinate space. By default the
Transformation is predetermined based on the plot
object type and the form of the data that is sent to it. However, for
the ContourPlot object, you can choose to use the
TriangularMeshTransformation to plot any kind of
data, or if ScalarField or
VectorField data has 2D coordinate arrays, you
can pick from as many as three Transformation
subclasses. In these cases there is not a simple test that can
automatically determine the most suitable class to use.
trGridType has five possible values:
Map
 Specifies the MapTransformation.
LogLin
 Specifies the LogLinTransformation.
Irregular
 Specifies the IrregularTransformation.
Curvilinear
 Specifies the CurvilinearTransformation.
Spherical
 Specifies the SphericalTransformation.
TriangularMesh
 Specifies the TriangularMeshTransformation.
trGridType is for the most part a readonly resource, except when the data grid is defined using 2D coordinate arrays or in the case of the ContourPlot whenever
TriangularMesh
is specified. When 2D coordinates are in effect, trGridType defaults toSpherical
but you may set itCurvilinear
orTriangularMesh
if the plot class supports it. For a ContourPlot you may specifyTriangularMesh
for any type of data grid.This resource may be intercepted or disabled by:
 trLineInterpolationOn (Transformation)

This resource controls the rendering of the lines between defined points
for XyPlot and for graphics primitives drawn using
NhlDataPolyline or NhlDataPolygon. If set False, lines
between the points are drawn as straight lines in NDC space. If set
True, points are interpolated between the defined points in order to
map the line into the data space.
This resource is disabled by:
 trXAxisType (IrregularTransformation)

This resource of type
NhlTAxisType
sets the type of transformation used for the X Axis. It has three
possible settings:
IrregularAxis
 Based on the values of the trXCoordPoints resource (and
possibly the trXInterPoints resource), an irregular
coordinate system is defined along the X Axis. If
trXCoordPoints is unset or found to be invalid, a warning
will be issued and trXAxisType will be reset to its default
value:
LinearAxis
. LogAxis
 A logarithmic coordinate system is established for the X Axis with
boundaries defined by the values of
trXMinF and
trXMaxF. If
trXMinF is less than or equal to 0.0, a
warning will be issued and trXAxisType will be reset to its
default value:
LinearAxis
. LinearAxis
 A linear coordinate system is established for the X Axis with boundaries defined by the values of trXMinF and trXMaxF.
This resource may be intercepted or disabled by:
 trXCoordPoints (IrregularTransformation)

If trXInterPoints is not set, this array resource represents
uniformly spaced samples of a bounded irregularly spaced data
coordinate system along the X Axis. The elements of
the array must be arranged in a monotonically increasing or decreasing
order. The coordinate system bounds are defined as the values of the
minimum and maximum elements of the array: in other words, its first
and last elements. If you superimpose on this coordinate system a
regular coordinate system such that the left end is 0 and the right end
is the number of elements in the array minus 1, then each succeeding
array element value represents the coordinate value of the irregular
coordinate system at successive integral coordinate points (0, 1, 2,
...) of the overlaid regular coordinate system. Note that these
integral coordinates correspond directly to the array element index
(with an offset of 1 when using a Fortran interface). Based on this
mapping, the IrregularTransformation sets up both a forward
and a reverse transformation.
trXCoordPoints is ignored unless trXAxisType is set to
IrregularAxis
. If the array contains less than two points or is nonmonotonic, a warning will be issued and trXAxisType will be reset to its default value:LinearAxis
.This resource may be intercepted or disabled by:
 trXInterPoints (IrregularTransformation)

This array resource, which, if set, must contain the same number of
points as trXCoordPoints, adds another step to the mapping
from regular to irregular coordinates. As in the case when
trXInterPoints is not set, you superimpose a bounded regular
coordinate system on the irregular coordinate system. Successive
elements of trXInterPoints, like those of
trXCoordPoints, must increase or decrease
monotonically. However, the element values have a range defined by the
bounds of the superimposed regular coordinate system (0 through array
size  1). Now the location of the data coordinate point specified by
each successive element of the trXCoordPoints is determined,
not by direct correlation with its array index, but by the value of
the corresponding element of the trXInterPoints array.
trXInterPoints is ignored unless trXAxisType is set to
IrregularAxis
. If trXInterPoints is found to be invalid, IrregularTransformation issues a warning message and computes the coordinate transformation as if it had not been set.This resource may be intercepted or disabled by:
 trXLog (LogLinTransformation)

If this boolean resource is True, the XAxis coordinate system is
logarithmic; otherwise it is linear. When this value is set True, both
trXMinF and
trXMaxF are required to be greater than
0.0.
This resource may be intercepted or disabled by:
 trXMaxF (Transformation)

Specifies a maximum X coordinate value that defines the upper bound
of the XAxis coordinate system. If trXMaxF is less than
trXMinF, the values will be exchanged before they are used to
establish coordinate boundaries. If the axis is irregular,
trXMaxF is constrained to lie within the bounds of the irregular
coordinate system as established by the XAxis coordinate array.
This resource may be intercepted or disabled by:
 trXMinF (Transformation)

Specifies a minimum X coordinate value that defines the lower bound of
the XAxis coordinate system. If trXMinF is greater than
trXMaxF, the values will be exchanged before they are used to
establish coordinate boundaries. If the axis is logarithmic,
trXMinF must be greater than 0.0. If the axis is irregular,
trXMinF is constrained to lie within the bounds of the irregular
coordinate system as established by the XAxis coordinate array.
This resource may be intercepted or disabled by:
 trXReverse (Transformation)

If the axis is linear or logarithmic, setting trXReverse
True results in a coordinate system that increases from right to left,
rather than in the usual direction from left to right. If the axis is
irregular, setting trXReverse True results in a reversal of
the direction of increasing coordinates as initially defined by the
ordering of the elements of the XAxis coordinate array.
This resource may be intercepted or disabled by:
 trXSamples (IrregularTransformation)

Specifies the number of sample points over the XAxis
coordinate system that IrregularTransformation is to use in
order to determine the reverse transformation. More sample points
(usually) increase the accuracy of the reverse transformation, but at
the cost of greater processing time for every transformation
calculated.
This resource may be intercepted or disabled by:
 trXTensionF (IrregularTransformation)
 Specifies the value of the tension parameter applied to the spline approximation used to set up the irregular transformation for the X Axis coordinate system. Small values (less than ~1.0) imply a relaxed approximation; large values (greater than ~5.0) imply a tight approximation. Note that large values of this parameter (>~10.0) may cause the transformation to become unstable or even fail.
 trYAxisType (IrregularTransformation)

This resource of type
NhlTAxisType
sets the type of transformation used for the Y Axis. It has three
possible settings:
IrregularAxis
 Based on the values of the trYCoordPoints resource (and
possibly the trYInterPoints resource), an irregular
coordinate system is defined along the Y Axis. If
trYCoordPoints is unset or found to be invalid, a warning
will be issued and trYAxisType will be reset to its default
value:
LinearAxis
. LogAxis
 A logarithmic coordinate system is established for the Y Axis with
boundaries defined by the values of
trYMinF and
trYMaxF. If
trYMinF is less than or equal to 0.0, a
warning will be issued and trYAxisType will be reset to its
default value:
LinearAxis
. LinearAxis
 A linear coordinate system is established for the Y Axis with boundaries defined by the values of trYMinF and trYMaxF.
This resource may be intercepted or disabled by:
 trYCoordPoints (IrregularTransformation)

If trYInterPoints is not set, this array resource represents
uniformly spaced samples of a bounded, irregularly spaced data
coordinate system along the Y Axis. The elements of the array must be
arranged in a monotonically increasing or decreasing order. The
coordinate system bounds are defined as the values of the minimum and
maximum elements of the array: in other words, its first and last
elements. If you superimpose on this coordinate system a regular
coordinate system such that the bottom end is 0 and the top end is the
number of elements in the array minus 1, then each succeeding array
element value represents the coordinate value of the irregular
coordinate system at successive integral coordinate points (0, 1, 2,
...) of the overlaid regular coordinate system. Note that these
integral coordinates correspond directly to the array element index
(with an offset of 1 when using a Fortran interface). Based on this
mapping, the IrregularTransformation sets up both a forward
and a reverse transformation.
trYCoordPoints is ignored unless trYAxisType is set to
IrregularAxis
. If the array contains less than two points or is nonmonotonic, a warning will be issued and trYAxisType will be reset to its default value:LinearAxis
.This resource may be intercepted or disabled by:
 trYInterPoints (IrregularTransformation)

This array resource, which, if set, must contain the same number of
points as trYCoordPoints, adds another step to the mapping
from regular to irregular coordinates. As in the case when
trYInterPoints is not set, you superimpose a bounded regular
coordinate system on the irregular coordinate system. Successive
elements of trYInterPoints, like those of
trYCoordPoints, must increase or decrease
monotonically. However, the element values have a range defined by the
bounds of the superimposed regular coordinate system (0 through array
size 1). Now the location of the data coordinate point specified by
each successive element of the trYCoordPoints is determined,
not by direct correlation with its array index, but by the value of
the corresponding element of the trYInterPoints array.
trYInterPoints is ignored unless trYAxisType is set to
IrregularAxis
. If trYInterPoints is found to be invalid, IrregularTransformation issues a warning message and computes the coordinate transformation as if it had not been set.This resource may be intercepted or disabled by:
 trYLog (LogLinTransformation)

If this boolean resource is True, the YAxis coordinate system is
logarithmic; otherwise it is linear. When this value is set True, both
trYMinF and
trYMaxF are required to be greater than
0.0.
This resource may be intercepted or disabled by:
 trYMaxF (Transformation)

Specifies a maximum Y coordinate value that defines the upper bound
of the YAxis coordinate system. If trYMaxF is less than
trYMinF, the values will be exchanged before they are used to
establish coordinate boundaries. If the axis is irregular,
trYMaxF is constrained to lie within the bounds of the irregular
coordinate system as established by the YAxis coordinate array.
This resource may be intercepted or disabled by:
 trYMinF (Transformation)

Specifies a minimum Y coordinate value that defines the lower bound of
the YAxis coordinate system. If trYMinF is greater than
trYMaxF, the values will be exchanged before they are used to
establish coordinate boundaries. If the axis is logarithmic,
trYMinF must be greater than 0.0. If the axis is irregular,
trYMinF is constrained to lie within the bounds of the irregular
coordinate system as established by the YAxis coordinate array.
This resource may be intercepted or disabled by:
 trYReverse (Transformation)

If the axis is linear or logarithmic, setting trYReverse to
True results in a coordinate system that increases from top to bottom,
rather than in the usual direction from bottom to top. If the axis is
irregular, setting trYReverse to True results in a reversal
of the direction of increasing coordinates as initially defined by the
ordering of the elements of the YAxis coordinate array.
This resource may be intercepted or disabled by:
 trYSamples (IrregularTransformation)

Specifies the number of sample points over the YAxis
coordinate system that IrregularTransformation is to use in
order to determine the reverse transformation. More sample points
(usually) increase the accuracy of the reverse transformation, but at
the cost of greater processing time for every transformation
calculated.
This resource may be intercepted or disabled by:
 trYTensionF (IrregularTransformation)

Specifies the value of the tension parameter applied to the spline
approximation used to set up the irregular transformation for the Y
Axis coordinate system. Small values (less than ~1.0) imply a relaxed
approximation; large values (greater than ~5.0) imply a tight
approximation. Note that large values of this parameter (>~10.0) may
cause the transformation to become unstable or even fail.
Default: 2.0