file_ps - writes intensity into PostScript file.

Calling Sequence

[field_out]=file_ps(field_in,fnam[,time[,gamma[,imax]]])

Parameters

• field_in :input field. it must be diffractive wavefront.
• fnam : the output filename, it must be a string.
• time : the timestamp of the outfile name. default time = -1. If the value of time is not positive,then the timestamp of the outfile will not be included.
• gamma : the value of contrast correction constant, default gamma=2.0. higher G gives better contrast in low intensities,
• imax : the grid dimension or sampling dimension (must be integer), default imax=128. it equals to grid sampling if you pass the zero to imax
• field_out : the output field or diffractive wavefront.

Description

file_ps writes the intensity distribution (density plot) of a field (field_in) into a postscript file. The program accepts other four arguments are: the filename (fnam), the grid dimension (imax) and the value of contrast correction constant (gamma) and the timestamp (time). The imax and gamma are optional, defaults are 128x128 and gamma=2 (it increases slightly the brightness in low-intensity regions, showing the distribution in a more natural way). The postscript output of 128x128 occupies approximately 32K on disk. When pow(2,n) sampling is used in calculations, the sampling of postscript graph must be also pow(2,n), i.e. 32,64,128,256,512....otherwise the filter does not report a wrong sampling, instead it adjusts automathically the sampling to nearest sensible value. Output file fnam.ps can be processed with any postscript devise.

Examples

	F1=begin(0.01,1e-6);
	F2=gauss(F1,0.004);
	
	file_ps(F2,"file1");	
	file_ps(F2,"file2",1);	
	file_ps(F2,"file3",-1,3);	
	file_ps(F2,"file4",-1,3,0);	
	file_ps(F2,"file5",-1,3,64);	
 

Author

Chen jingyuan, Gan guangyong (IAPCM, Beijing,China.)

See Also

dwf_fits ,   file_pgm ,   file_int ,   file_pha ,   cros_out ,