Cleanup Winston plots and histograms in examples

Author: alanedelman

demos/book/1/bellcurve.jl

@@ -9,20 +9,18 @@
 t=1000000
 dx=.2
 v=randn(t)
-count=hist(v,[-4-dx/2:dx:4+dx/2])
-count/=sum(count)*dx
+grid=[-4:dx:4]
+count=hist(v,grid)/(t*dx)
 
 ## Theory
-x=[-4:dx:4]
+x=grid
 y=exp(-x.^2/2)/sqrt(2*pi)
 
 ## Plot
-#XXX Currently Histogram() must start plotting from 0.
-#For now, add offset to theoretical curve
-#Filed: https://github.com/nolta/Winston.jl/issues/28
-#cjh 2013-03-16
 using Winston
 p = FramedPlot()
-add(p, Histogram(count, dx))
-add(p, Curve(x+4+dx/2, y, "color", "blue", "linewidth", 2)) 
+h = Histogram(count, dx)
+h.x0 = grid[1]
+add(p, h)
+add(p, Curve(x, y, "color", "blue", "linewidth", 2)) 
 file(p, "bellcurve.png")

demos/book/1/largeeig.jl

@@ -12,6 +12,7 @@ n=100        # matrix size
 t=5000       # trials
 v=[]         # eigenvalue samples
 dx=.2        # binsize
+grid=[-5:dx:2]
 ## Experiment
 for i=1:t
     a=randn(n,n)+im*randn(n,n) # random nxn complex matrix
@@ -20,20 +21,17 @@ for i=1:t
 end
 v=n^(1/6)*(v-2*sqrt(n))        # normalized eigenvalues
 
-count=hist(v,-5:dx:2)
-count/=t*dx
+count=hist(v,grid)/(t*dx)
 
 ## Theory
 (t, f) = tracywidom(5., -8.)
 
 ## Plot
-#XXX Currently Histogram() must start plotting from 0.
-#For now, add offset to theoretical curve
-#Filed: https://github.com/nolta/Winston.jl/issues/28
-#cjh 2013-03-16
 using Winston
 p = FramedPlot()
-add(p, Histogram(count, dx))
+h = Histogram(count, dx)
+h.x0 = grid[1]
+add(p, h)
 add(p, Curve(t+5, f, "linewidth", 2, "color", "blue")) 
 file(p, "largeeig.png")
 

demos/book/1/semicircle.jl

@@ -9,21 +9,23 @@ n=1000       # matrix size
 t=10         # trials
 v=[]         # eigenvalue samples
 dx=.2        # binsize
+grid=[-2.4:dx:2.4]
 ## Experiment
 for i = 1:t
     a=randn(n,n)      # n by n matrix of random Gaussians
     s=(a+a')/sqrt(2*n)# symmetrize and normalize matrix
     v=[v;eig(s)[1]]   # eigenvalues
 end
-count=hist(v,-2.4:dx:2.4)
-count/=n*t*dx
+count=hist(grid)/(n*t*dx)
 ## Theory
 x=[-2:dx:2]
 y=sqrt(4-x.^2)/(2*pi)
 
 ## Plot
 using Winston
 p = FramedPlot()
-add(p, Histogram(count, dx))
+h = Histogram(count, dx)
+h.x0 = grid[1]
+add(p, h)
 add(p, Curve(x+2.4+dx/2, y, "color", "blue", "linewidth", 2)) 
 file(p, "semicircle.png")