github.com/astrogo/cfitsio@v0.1.0/examples/go-cfitsio-fitscopy/main.go (about) 1 package main 2 3 import ( 4 "flag" 5 "fmt" 6 "os" 7 8 fits "github.com/astrogo/cfitsio" 9 ) 10 11 func main() { 12 flag.Parse() 13 if flag.NArg() != 2 { 14 flag.Usage = func() { 15 const msg = `Usage: go-cfitsio-fitscopy inputfile outputfile 16 17 Copy an input file to an output file, optionally filtering 18 the file in the process. This seemingly simple program can 19 apply powerful filters which transform the input file as 20 it is being copied. Filters may be used to extract a 21 subimage from a larger image, select rows from a table, 22 filter a table with a GTI time extension or a SAO region file, 23 create or delete columns in a table, create an image by 24 binning (histogramming) 2 table columns, and convert IRAF 25 format *.imh or raw binary data files into FITS images. 26 See the CFITSIO User's Guide for a complete description of 27 the Extended File Name filtering syntax. 28 29 Examples: 30 31 go-cfitsio-fitscopy in.fit out.fit (simple file copy) 32 go-cfitsio-fitscopy - - (stdin to stdout) 33 go-cfitsio-fitscopy in.fit[11:50,21:60] out.fit (copy a subimage) 34 go-cfitsio-fitscopy iniraf.imh out.fit (IRAF image to FITS) 35 go-cfitsio-fitscopy in.dat[i512,512] out.fit (raw array to FITS) 36 go-cfitsio-fitscopy in.fit[events][pi>35] out.fit (copy rows with pi>35) 37 go-cfitsio-fitscopy in.fit[events][bin X,Y] out.fit (bin an image) 38 go-cfitsio-fitscopy in.fit[events][col x=.9*y] out.fit (new x column) 39 go-cfitsio-fitscopy in.fit[events][gtifilter()] out.fit (time filter) 40 go-cfitsio-fitscopy in.fit[2][regfilter("pow.reg")] out.fit (spatial filter) 41 42 Note that it may be necessary to enclose the input file name 43 in single quote characters on the Unix command line. 44 ` 45 fmt.Fprintf(os.Stderr, "%v\n", msg) 46 } 47 flag.Usage() 48 os.Exit(1) 49 } 50 51 // open input file 52 in, err := fits.Open(flag.Arg(0), fits.ReadOnly) 53 if err != nil { 54 panic(err) 55 } 56 defer in.Close() 57 58 // create output file 59 out, err := fits.Create(flag.Arg(1)) 60 if err != nil { 61 panic(err) 62 } 63 defer out.Close() 64 65 // copy every HDU until we get an error 66 for i := 1; err == nil; i++ { 67 err = in.SeekHDU(i, 0) 68 if err != nil { 69 break 70 } 71 err = fits.CopyHDU(&out, &in, 0) 72 } 73 if err != nil && err != fits.END_OF_FILE { 74 panic(err) 75 } 76 }