makebospattern(N,D) makes a figure filled with N randomly distributed 
dots of diameter D for SS (Synthetic Schlieren), BOS (Background- 
oriented Schlieren) or FS-SS (Free-Surface SS) applications. 
 
The figure format is portrait (ie, vertical) A4, 210x297 mm, and the 
particle diameter D is in mm. Typical values are N=50000, D=1. 
 
makebospattern(N,D,'b') makes black points on a white ground (by 
default). makebospattern(N,D,'w') makes white points on a black ground. 
 
makebospattern(N,D,'..',FILENAME) saves the result in a 300-DPI TIFF 
figure. Use the standard Windows viewer to print the figure. 
 
Notes: 
  - If you zoom the figure, the particles are not resized: particles 
  are drawn in absolute units (points), while the paper size is in 
  physical units (centimeters). 
  - a 'particle' is a set of 4 concentric circles with increasing (or 
  decreasing) gray levels. The 'particle diameter' D is the diameter of 
  the outer circle; the inner circle has diameter 0.3*D. Depending on 
  the printer quality, the outer circle may not print correctly, so the 
  actual size may appear slightly larger or smaller than the requested 
  size. 
  - for FS-SS applications, see the function surfheight for the 
  surface height reconstruction. 
 

 
   makebospattern(50000,1,'w','myfig'); 
 

PRINT, surfheight 
Published output in the Help browser 
   showdemo makebospattern