; IDL Version 5.2 (sunos sparc)
; Journal File for rwo@gemini.astro.Virginia.EDU
; Working directory: /net/gemini.vela/rwo/511/jnl
; Date: Wed Sep 24 14:06:01 2003

 ;;; Generate a 200x200 array filled with random noise characterized
 ;;;  by a Poisson distribution with mean 10/pixel

noise=randomn(seed,200,200,poisson=10)
show,noise,3
; 

zoomer
;Left for zoom center, Middle for new zoom factor, Right to quit

chan,9

 ;;; Plot row slices through array. Does it "look" random?

plot,noise(*,100)
plot,noise(*,101)
plot,noise(*,102)
plot,noise(*,108)

 ;;; Plot histogram for individual pixels in full array

plothist,noise
meanarray,noise
; 
;     Mean        RMS     SE(Mean)        Max         Min 
;      9.998      3.159      0.016     2.6000e+01  0.0000e+00


 ;;; Generate  20 pixel samples and find means; repeat a total
 ;;;   of 200 times:

samp20=fltarr(200)

for i=0,199 do samp20(i)=mean(noise(0:19,i))   

 ;;; Compare parent histogram to histogram of 20-pixel means

plothist,samp20,xs,ys,bin=0.2,/noplot
chan,9
plothist,noise
oplot,xs,ys*200,psym=10

 ;;; The width of the sample mean distribution should be
 ;;;  smaller by factor sqrt(20).