From f51c5260a7a1b90e052929f25775149d809c219b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Arnstr=C3=B6m?=
 <55484604+darnstrom@users.noreply.github.com>
Date: Wed, 8 Jan 2025 14:27:49 +0100
Subject: [PATCH] v0.2.1 (#12)

* Normalize and rows in general parameter constraints

* only normalize if norm_factor > 0

* v0.2.1
---
 Project.toml   |  2 +-
 src/mpsolve.jl |  7 ++++++-
 src/utils.jl   | 28 ++++++++++++++++++++++++----
 3 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/Project.toml b/Project.toml
index a5e0ae4..2a9bd4c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ParametricDAQP"
 uuid = "19f72acb-e2a9-45c8-96b9-4d5487c8db2e"
 authors = ["Daniel Arnström <daniel.arnstrom@gmail.com>"]
-version = "0.2.0"
+version = "0.2.1"
 
 [deps]
 DAQP = "c47d62df-3981-49c8-9651-128b1cd08617"
diff --git a/src/mpsolve.jl b/src/mpsolve.jl
index 7564358..2092261 100644
--- a/src/mpsolve.jl
+++ b/src/mpsolve.jl
@@ -27,6 +27,11 @@ function mpsolve(mpQP,Θ;opts=nothing, AS0 = nothing) # bounds_table as option
     # Setup parametric problem and normalize
     prob = setup_mpp(mpQP;fix_ids,fix_vals)
     prob, Θ, tf = normalize_parameters(prob,Θ)
+    if(isnothing(prob)) # Θ makes the problem trivially infeasible
+        @warn "The parameter region of interest is empty"
+        F,info = CriticalRegion[], (solve_time = 0, nCR = 0, nLPs = 0, nExplored = 0,status=:EmptyParameterRegion)
+    end
+
 
     if(isnothing(AS0))
         AS0 = compute_AS0(prob,Θ)
@@ -50,7 +55,7 @@ function mpdaqp_explicit(prob,Θ,AS0;opts = Settings())
     if(length(id_cands) < m)
         id_zeros = findall(prob.norm_factors .≤ opts.eps_zero)
         opts.verbose >  0 && @warn "Rows $id_zeros in A are zero → seen as parameter constraints" 
-        if hasproperty(Θ,:Ath)
+        if hasproperty(Θ,:A)
             A = [Θ.A -prob.d[1:end-1,id_zeros]]
             b = [Θ.b; prob.d[end,id_zeros]]
         else
diff --git a/src/utils.jl b/src/utils.jl
index a9377c6..3691682 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -48,8 +48,10 @@ function setup_mpp(mpQP;normalize=true, fix_ids=Int[],fix_vals=zeros(0))
         norm_factor = 0
         for i in 1:m
             norm_factor = norm(view(M,i,:),2) 
-            M[i,:]./=norm_factor
-            d[:,i]./=norm_factor
+            if(norm_factor > 0)
+                M[i,:]./=norm_factor
+                d[:,i]./=norm_factor
+            end
             norm_factors[i]= norm_factor
         end
     end
@@ -65,7 +67,7 @@ function setup_mpp(mpQP;normalize=true, fix_ids=Int[],fix_vals=zeros(0))
 end
 
 ## Normalize parameters to -1 ≤ θ ≤ 1
-function normalize_parameters(prob::MPLDP,Θ)
+function normalize_parameters(prob::MPLDP,Θ;eps_zero=1e-12)
     if(isempty(Θ.ub)) # assume already normalized
         return prob,Θ,(center=0,scaling = 1)
     end
@@ -80,8 +82,26 @@ function normalize_parameters(prob::MPLDP,Θ)
 
     Ath = haskey(Θ,:A) ? Θ.A : zeros(nth,0);
     bth = haskey(Θ,:b) ? Θ.b : zeros(0);
-    Θ =(A=norm_factors.*Ath, b = bth-(center'*Ath)[:], # TODO: verify
+
+    # Normalize A to box -1 ≤ θ ≤ 1
+    A = norm_factors.*Ath
+    b = bth-(center'*Ath)[:]
+
+    # Normalize A
+    is_nonzero = falses(length(b))
+    for i in 1:length(b)
+        norm_factor = norm(view(A,:,i),2);
+        if(norm_factor>eps_zero)
+            rdiv!(view(A,:,i),norm_factor)
+            b[i]/=norm_factor
+            is_nonzero[i] = true
+        else
+            (b[i]<-eps_zero) && return nothing,nothing,nothing # trivially infeasible
+        end
+    end
+    Θ =(A=A[:,is_nonzero], b = b[is_nonzero], # TODO: verify
         lb = -ones(nth), ub = ones(nth));
+
     return prob, Θ,(center=center, scaling = 1 ./ norm_factors)
 end
 function normalize_parameters(prob::MPQP,Θ)