European Space Agency

Royal Belgian Institute for Aeronomy

ud327 - search an extremum

subroutine  ud327(mgp1, mgp2, mgp3, fct1, fct2, fct3, mextr, est, ifail)

Parameters:

• mgp1 [zgeo,in] :: First point

• mgp2 [zgeo,in] :: Second point

• mgp3 [zgeo,in] :: Third point

• fct1 [real8,in] :: value at location mgp1

• fct2 [real8,in] :: value at location mgp2

• fct3 [real8,in] :: value at location mgp3

• mextr [zgeo,out] :: Location of the extremum

• est [real8,out] :: Estimation of the function at the extremum

• ifail [integer4,out] :: error flag (see Diagnostics)

Description

The subroutine ud327() makes a parabolic interpolation between three geographic positions and deduces the location of the extremum.

References

History

• The subroutine ud327() does not exist in version 1.05 and earlier.

• The argument est is not part of the subroutine synopsis in version 2.00 and earlier.

• Errors in the algorithm and its implementation have been fixed in version 2.01.

Diagnostics

• -32701, no extremum

Common Blocks

• uc160 - general constants

Dependencies

Called by

• ud315 - search the mirror point with the lowest altitude

Calls

None

See also

None

Reported Bugs

None

Examples

None

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UNILIB/tags/v3.02