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SDsetcal/sfscal

intn SDsetcal(int32 sds_id, float64 cal, float64 cal_err, float64 offset, float64 offset_err, int32 data_type)

sds_id IN:

Data set identifier returned by SDcreate or SDselect

cal IN:

Calibration factor

cal_err IN:

Calibration error

offset IN:

Uncalibrated offset

offset_err IN:

Uncalibrated offset error

data_type IN:

Data type of uncalibrated data

Purpose

Sets the calibration information.

Return value

Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.

Description

SDsetcal stores the calibration record associated with a data set. A calibration record contains the following information:

cal

Calibration factor

cal_err

Calibration error

offset

Uncalibrated offset

offset_err

Uncalibrated offset error

data_type

Data type of uncalibrated data

The relationship between a value cal_value stored in a data set and the original value is defined as: orig_value = cal * (cal_value - offset).

The variable offset_err contains a potential error of offset, and cal_err contains a potential error of cal. Currently the calibration record is provided for information only. The SD interface performs no operations on the data based on the calibration tag.

The calibration information is automatically cleared after a call to SDreaddata or SDwritedata. Therefore, SDsetcal must be called once for each data set that is to be read or written.

FORTRAN

integer function sfscal(sds_id, cal, cal_err, offset, offset_err, data_type)

integer sds_id, data_type

real*8 cal, cal_err, offset, offset_err



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HDF Reference Manual - 07/29/98, NCSA HDF Development Group.