Returns status information. This information might prove useful to
the user wanting to gain better control over the differencing
parameters. This information can often be ignored.
Namespace:
Imsl.Math
Assembly:
ImslCS (in ImslCS.dll) Version: 6.5.0.0
Syntax
C# |
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public int[] GetStats() |
Visual Basic (Declaration) |
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Public Function GetStats As Integer() |
Visual C++ |
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public:
array<int>^ GetStats() |
Return Value
An
int array containing the ten diagnostic values
described in the following table. These values can be used to
monitor the progress or expense of the Jacobian computation.
index | Description |
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0 | the number of times a function evaluation was
computed. |
1 | the number of columns in which three attempts were
made to increase a percentage factor for differencing (i.e. a
component in the factor array) but the computed del
remained unacceptably small relative to y[j-1] or
scale[j-1]. In such cases the percentage factor is
set to 1.4901161193847656e-8, which is the square root of machine
precision |
2 | the number of columns in which the computed del
was zero to machine precision because y[j-1] or
scale[j-1] was zero. In such cases del is
set to 1.4901161193847656e-8, which is the square root of machine
precision |
3 | the number of Jacobian columns which had to be
recomputed because the largest difference formed in the column was
close to zero relative to scale, where
and i denotes the row index of the largest difference in the
column currently being processed. index = 9 gives the last
column where this occurred. |
4 | the number of columns whose largest difference is
close to zero relative to scale after the column has been
recomputed. |
5 | the number of times scale information was not
available for use in the roundoff and truncation error tests. This
occurs when
where i is the index of the largest difference for the column
currently being processed. |
6 | the number of times the increment for differencing
(del) was computed and had to be increased because
(scale[j-1]+del) - scale[j-1])
was too small relative to y[j-1] or
scale[j-1]. |
7 | the number of times a component of the
factor array was reduced because changes in function values
were large and excess truncation error was suspected.
index = 8 gives the last column in which this occurred. |
8 | the index of the last column where the
corresponding component of the factor array had to be
reduced because excessive truncation error was suspected. |
9 | the index of the last column where the difference
was small and the column had to be recomputed with an adjusted
increment (see index = 3). The largest derivative in this
column may be inaccurate due to excessive roundoff error. |
See Also