matlab.io.fits.writeKeyUnit

Write physical units string

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Syntax

matlab.io.fits.writeKeyUnit(fptr,keyname,unit)

Description

matlab.io.fits.writeKeyUnit(fptr,keyname,unit) writes the physical units to the specified keyword. Specify the keyname and unit arguments as string scalars or character vectors.

Examples

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Open Live Script

Create a new FITS file and add an image to it.

import matlab.io.*
fptr = fits.createFile("myfile.fits");
fits.createImg(fptr,"long_img",[10 20])

Write the VELOCITY keyword to the current HDU, and set the keyword's units to kilometers per second. Then close the file.

fits.writeKey(fptr,"VELOCITY",12.3,"orbital speed")
fits.writeKeyUnit(fptr,"VELOCITY","km/s")
fits.closeFile(fptr)

Examine the file metadata and then delete the file.

fitsdisp("myfile.fits",Mode="full")
HDU:  1 (Primary HDU)
	SIMPLE  =                    T / file does conform to FITS standard
	BITPIX  =                   32 / number of bits per data pixel
	NAXIS   =                    2 / number of data axes
	NAXIS1  =                   20 / length of data axis 1
	NAXIS2  =                   10 / length of data axis 2
	EXTEND  =                    T / FITS dataset may contain extensions
	COMMENT   FITS (Flexible Image Transport System) format is defined in 'Astronomy
	COMMENT   and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
	VELOCITY=                 12.3 / [km/s] orbital speed

delete myfile.fits

Tips

  • This function corresponds to the fits_write_key_unit (ffpunt) function in the CFITSIO library C API.

  • To use this function, you must be familiar with the CFITSIO C interface. You can access the CFITSIO documentation at the CFITSIO website.

Extended Capabilities

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Version History

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See Also