Hi, all,
I'm a brand-new julia user trying to convert some matlab code to julia.
When I run the code, I am currently getting a stack trace that looks like
this:
0 ERROR: LoadError: TypeError: non-boolean (Array{Bool,2}) used in
boolean context
in tvd at /home/bcrowell/tvd/tvd.jl:145
in tvd at /home/bcrowell/tvd/tvd.jl:53
in include at ./boot.jl:254
in include_from_node1 at loading.jl:133
in process_options at ./client.jl:306
in _start at ./client.jl:406
while loading /home/bcrowell/tvd/test.jl, in expression starting on line 3
Am I correct in assuming that in output like "...tvd.jl:145", the 145 is
supposed to be a line number in tvd.jl? I couldn't figure out what was
wrong, but I noticed that when I fiddled with the code in attempts to fix
or track down the error, the 145 was always 145, even when it seemed like
it should have changed. I then started trying to make a minimal example,
and I ended up with code that was only 114 lines long, but the error was
still claimed to be at line 145 -- a line that doesn't exist. This is with
julia 0.4.0-dev.
Normally I would not post a question on a newsgroup like this without first
whittling my problem down to a minimal example, but this seeming inaccuracy
of the line numbers is making it hard for me to do so. I've therefore
posted the 114-line version of the code below, just so people can see what
I'm talking about and try to reproduce the behavior if they wish.
Without expecting anyone to debug my whole program for me ...
...am I correct that the 145 is supposed to be a line number?
...is this a known issue?
Thanks in advance,
Ben
===============================================================================================================
# converted from the matlab function tvdip() at
http://www.maxlittle.net/software/ , GPL v2
function tvd(y, lambda, display=true, stoptol=1e-3, maxiter=60)
# Search tuning parameters
ALPHA = 0.01 # Backtracking linesearch parameter (0,0.5]
BETA = 0.5 # Backtracking linesearch parameter (0,1)
MAXLSITER = 20 # Max iterations of backtracking linesearch
MU = 2 # t update
N = length(y) # Length of input signal y
M = N-1 # Size of Dx
# Construct sparse operator matrices
I1 = speye(M,M) # sparse identity matrix
O1 = spzeros(M,1) # column vector initialized with zero
D = [I1 O1]-[O1 I1] # negative differentiation operator, 1 on main diag, -1
to right
DDT = D*D' # second derivative operator, 2 on main diag, -1 on diagonals
two steps above and below it
Dy = D*y
# Find max value of lambda
lambdamax = maximum(abs(DDT\Dy)) # x=A\B ... solves Ax=B
L = length(lambda)
x = zeros(N, L)
s = zeros(L, 1)
E = zeros(L, 1)
# Optimization variables set up once at the start
z = zeros(M,1) # Dual variable
mu1 = ones(M,1) # Dual of dual variable
mu2 = ones(M,1) # Dual of dual variable
# Work through each value of lambda, with hot-restart on optimization
# variables
for l = 1:L
t = 1e-10
step = Inf
f1 = z-lambda[l]
f2 = -z-lambda[l]
# Main optimization loop
s[l] = 1
for iters = 0:maxiter
DTz = (z'*D)'
DDTz = D*DTz
w = Dy-(mu1-mu2)
# Calculate objectives and primal-dual gap
pobj1 = 0.5*w'*(DDT\w)+lambda[l]*sum(mu1+mu2)
pobj2 = 0.5*DTz'*DTz+lambda[l]*sum(abs(Dy-DDTz))
pobj = min(pobj1,pobj2)
dobj = -0.5*DTz'*DTz+Dy'*z
gap = pobj - dobj
if display
@printf("%5d %7.2e %7.2e %7.2e\n", iters, pobj, dobj, gap)
end
# Test duality gap stopping criterion
if gap <= stoptol
s(l) = 1
break
end
if step >= 0.2
t = max(2*M*MU/gap, 1.2*t)
end
dmu1 = mu1
dmu2 = mu1
resDual = rz
resCent = [-mu1.*f1-1/t; -mu2.*f2-1/t]
residual= [resDual; resCent]
# Perform backtracking linesearch
step = 1
for i = 1:length(dmu1)
if dmu1[i]<0
step = minimum( step, 0.99*min(-mu1[i]./dmu1[i]) ) # I get an
error on this line, even if I comment it out!?
end
end
for i = 1:length(dmu2)
if dmu2[i]<0
step = minimum( step, 0.99*min(-mu2[i]./dmu2[i]) )
end
end
end
x(:,l) = y-D'*z
E(l) = 0.5*sum((y-x(:,l)).^2)+lambda[l]*sum(abs(D*x(:,l)))
# We may have a close solution that does not satisfy the duality gap
if iters >= maxiter
s(l) = 0
end
if display
if s(l)
@printf("Solved to precision of duality gap %5.2e\n", gap)
else
@printf("Max iterations exceeded - solution may be
inaccurate\n")
end
end
end
end
(x,E,s,lambdamax) = tvd([10, 11, 9, 10],1)
