fix primal-dual parameter choices

scripts/run_experiments.jl

@@ -988,10 +988,12 @@ function denoise_pd(ctx)
 
     # semi-implicit primal dual parameters
     mu = st.alpha2 + st.beta # T = I, S = I
-    mu /= 100 # kind of arbitrary?
+    #mu /= 100 # kind of arbitrary?
 
-    tau = 1e-1
     L = norm_gradient(mesh)
+    #tau = 1e-1
+    tau = 1 / L
+    #L = 100
     sigma = inv(tau * L^2)
     theta = NaN # initialized later
 
@@ -1022,6 +1024,7 @@ function denoise_pd(ctx)
         while true
             k += 1
             if ctx.params.algorithm == :pd1
+                theta = 1 / sqrt(1 + 2 * mu * tau) # constant
                 # no step size control
                 step_pd2!(st; sigma, tau, theta)
             elseif ctx.params.algorithm == :pd2
@@ -1322,6 +1325,7 @@ function experiment_approximation(ctx)
 end
 
 # TODO: deduplicate, cf. optflow()
+# NOTE: used also by inpaint_denoise experiment
 function inpaint(ctx)
     # expect ctx.params.g_arr