Gif stuff

nonlinear MLSE investigation
trying hard to implment ML-based pre Equalization to find the branch metrics
This commit is contained in:
Silas Oettinghaus
2025-10-24 16:58:06 +02:00
parent c33264a515
commit 7085ba0931
16 changed files with 1414 additions and 162 deletions

View File

@@ -344,7 +344,7 @@ classdef Signal
arguments
obj
options.fignum
options.fignum = 2025
options.displayname = "";
options.color = [];
options.normalizeToNyquist = 0;
@@ -449,21 +449,25 @@ classdef Signal
ylabel(ylab);
% --- Y-Axis scaling (auto with margin) ---
y_min = min(p_dbm(:));
y_max = max(p_dbm(:));
% Add 5% dynamic range margin on both sides
y_range = y_max - y_min;
if y_range == 0
y_range = 10; % fallback if flat
end
y_margin = 0.05 * y_range;
ylim([y_min - y_margin, y_max + y_margin]);
% Set ticks automatically, avoid overpopulation
try
ylim([max(min(floor(min(p_dbm))-3, ax.YLim(1)),-40), min(max(ceil(max(p_dbm))+3, ax.YLim(2)),10)]);
catch
ylim([floor(min(p_dbm,[],'all'))-3, ceil(max(p_dbm,[],'all'))+3]);
yticks(round(linspace(y_min, y_max, min(10, max(4, ceil(y_range/10))))));
end
if options.normalizeTo0dB
ylim([floor(min(p_dbm,[],'all'))-3, ceil(max(p_dbm,[],'all'))+3]);
else
ylim([floor(min(p_dbm,[],'all'))-3, ceil(max(p_dbm,[],'all'))+3]);
end
yticks(-200:10:10);
grid on;
legend
end
@@ -961,8 +965,8 @@ classdef Signal
maxA = max(sig(100:end-100))*1.3;
minA = min(sig(100:end-100))*1.3;
% maxA = 0.0015;
% minA = 0;
maxA = 0.0025;
minA = 0;
difference= maxA-minA;
@@ -1012,7 +1016,7 @@ classdef Signal
% add information
if 1
if 0
pwr_dbm = round(obj.power,3);
pwr_lin = obj.power("unit",power_notation.W);
@@ -1121,20 +1125,20 @@ classdef Signal
end
yticks(linspace(0,histpoints,6));
y_tickstring = sprintfc('%.2f', y_tickstring);
yticklabels(y_tickstring);
xticks(linspace(0,histpoints_horizontal,6))
x_tickstring = sprintfc('%.2f', linspace(0, 2/fsym, 8) .* 1e12);
xticklabels(x_tickstring);
grid off
end
yticks(linspace(0,histpoints,6));
y_tickstring = sprintfc('%.2f', y_tickstring);
yticklabels(y_tickstring);
xticks(linspace(0,histpoints_horizontal,6))
x_tickstring = sprintfc('%.2f', linspace(0, 2/fsym, 8) .* 1e12);
xticklabels(x_tickstring);
%
end
% disp('h');

View File

@@ -131,7 +131,7 @@ classdef FFE < handle
mask = ones(obj.order,1);
maincursor_pos=ceil(length(obj.e)/2);
always_ideal_decision = 0;
save_debug = 1;
save_debug = 0;
grad =0;
weight = 0;
update = 0;

View File

@@ -0,0 +1,233 @@
classdef ML_MLSE < handle
% Implementation of plain and simple FFE.
% 1) Training mode (stable performance when you use NLMS)
% 2) Decision directed mode
%LMS: mu in order of 0.0001 for acceptable convergence speed
%NLMS: mu in order of 0.01 for acceptable convergence speed
%RLS: mu is lambda -> 0.99 -> 1 (has a strong dependency on this! use a loop to find out best values)
% FFE("epochs_tr",5,"epochs_dd",2,"len_tr",2^13,"mu_dd",mu_dd,"mu_tr",mu_tr,"order",25,"sps",2,"decide",0, "adaption",adaption_method(adaption),"dd_mode",use_dd_mode);
properties
sps % usually 2
order
e
e_tr
error
len_tr
mu_tr
epochs_tr
dd_mode % 1 or 0 to set DD-mode on or off
mu_dd %weight update in dd mode
epochs_dd
constellation
L %viterbi memory length
alpha
DIR
DIR_flip
trellis_states
traceback_depth
end
methods
function obj = ML_MLSE(options)
arguments(Input)
options.sps = 2;
options.order = 15;
options.len_tr = 4096;
options.mu_tr = 0;
options.epochs_tr = 5;
options.dd_mode = 1;
options.mu_dd = 1e-5;
options.epochs_dd = 5;
options.traceback_depth = 1024;
options.L = 1
end
fn = fieldnames(options);
for n = 1:numel(fn)
obj.(fn{n}) = options.(fn{n});
end
obj.e = zeros(obj.order,1);
obj.error = 0;
end
function [X,X_viterbi] = process(obj, X, D)
% actual processing of the signal (steps 1. - 3.)
% 1 normalize RMS
X = X.normalize("mode","rms");
obj.constellation = unique(D.signal);
if length(X)/length(D) ~= obj.sps
warning('Signal length does not fit to reference!');
end
% Training Mode
n = obj.len_tr;
training = 1;
obj.equalize(X.signal, D.signal,obj.mu_tr,obj.epochs_dd,n,training);
obj.e_tr = obj.e;
% Decision Directed Mode
n = X.length;
training = 0;
[y,y_vit]=obj.equalize(X.signal, D.signal,obj.mu_dd,obj.epochs_dd,n,training);
X_viterbi = X;
X.signal = y;
X.fs = D.fs; %change sampling frequency of outgoing signal from fdac e.g. 2 sps to symbol spaced = fsym
lbdesc = [num2str(obj.order),' tap FFE'];
X = X.logbookentry(lbdesc); % append to logbook
X_viterbi.signal = y_vit;
X_viterbi.fs = D.fs; %change sampling frequency of outgoing signal from fdac e.g. 2 sps to symbol spaced = fsym
lbdesc = [num2str(obj.order),'order FFE + PF + Viterbi'];
X_viterbi = X_viterbi.logbookentry(lbdesc); % append to logbook
end
function [y,y_vit] = equalize(obj,x,d,mu,epochs,N,training)
% ==============================================================
% FFE + Whitening + Viterbi Equalizer (reference implementation)
% ==============================================================
% --- Input padding and preallocation
x = [zeros(floor(obj.order/2),1); x; zeros(obj.order,1)];
N_ = N / obj.sps;
y = zeros(N_,1);
y_white = zeros(N_,1);
for epoch = 1:epochs
% ==============================================================
% INITIALIZATION (only before final epoch and detection mode)
% ==============================================================
if epoch == epochs && ~training
% --- Parameters
S = numel(unique(d));
L = obj.L;
nStates = S^L;
nFeasible = S^(L-1)*S;
% --- Trellis setup
obj.DIR = arburg(y-d, L);
obj.DIR_flip = flip(obj.DIR);
obj.trellis_states = reshape(unique(d),1,[]);
pre_comb_mat = repmat(obj.trellis_states, L, 1);
pre_comb_cell = mat2cell(pre_comb_mat, ones(1,L), size(pre_comb_mat,2));
combs = fliplr(combvec(pre_comb_cell{:}).');
first_sym = combs(:,1);
last_sym = combs(:,end);
nStates = size(combs,1);
noise_free_received = inf(nStates,nStates);
valid = false(nStates);
for from = 1:nStates
for to = 1:nStates
if all(combs(to,2:end) == combs(from,1:end-1))
noise_free_received(to,from) = ...
dot(combs(to,:), obj.DIR_flip(end:-1:2)) + last_sym(from)*obj.DIR_flip(1);
valid(to,from) = true;
end
end
end
nf_vec = noise_free_received(valid);
[valid_to, valid_from] = find(valid);
from_per_to = arrayfun(@(to)find(valid(to,:)), 1:nStates, 'UniformOutput', false);
% --- Noise stats
y_ideal = conv(d(:), obj.DIR(:), "same");
sigma2 = mean(abs(y - y_ideal).^2);
inv2s2 = 1/(2*sigma2);
% --- Vector initialization
bm_vec = zeros(1,nFeasible);
pm = zeros(nStates,1);
pm_next = zeros(nStates,1);
bm_fw = zeros(nStates,nStates,length(y));
zi = zeros(max(numel(obj.DIR)-1,0),1);
end
% ==============================================================
% RUNTIME LOOP (FFE update + Viterbi detection in last epoch)
% ==============================================================
symbol = 0;
for sample = 1:obj.sps:N
symbol = symbol + 1;
% --- FFE output
U = x(obj.order+sample-1:-1:sample);
y(symbol,1) = obj.e.' * U;
% --- Decision
if training
d_hat(symbol,1) = d(symbol);
else
[~,symbol_idx] = min(abs(y(symbol) - obj.constellation));
d_hat(symbol,1) = obj.constellation(symbol_idx);
end
% --- LMS weight update
err(symbol) = d_hat(symbol) - y(symbol);
obj.e = obj.e + mu * (err(symbol) * U);
% --- Whitening + Viterbi (final epoch only)
if epoch == epochs && ~training
[y_white(symbol), zi] = filter(obj.DIR,1,y(symbol), zi);
if symbol == 1
pm = -inf(nStates,nStates);
pm(:,1:nStates) = 0;
else
bm_vec = -(y_white(symbol) - nf_vec).^2 * inv2s2;
bm_mat = -inf(nStates,nStates);
bm_mat(valid) = bm_vec;
pm_new = pm + bm_mat;
[pm_survive(:,symbol), pm_survivor_fw_idx(:,symbol)] = max(pm_new,[],2);
pm = repmat(pm_survive(:,symbol).', nStates,1);
end
% --- Traceback
if mod(symbol,obj.traceback_depth) == 0
[~,viterbi_path(symbol)] = max(pm_survive(:,symbol));
for n = symbol:-1:symbol-obj.traceback_depth+2
viterbi_path(n-1) = pm_survivor_fw_idx(viterbi_path(n),n);
end
end
end
end
% --- Final reconstruction
if epoch == epochs && ~training
y_vit = first_sym(viterbi_path);
end
end
end
end
end

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@@ -0,0 +1,246 @@
classdef ML_MLSE < handle
% Implementation of plain and simple FFE.
% 1) Training mode (stable performance when you use NLMS)
% 2) Decision directed mode
%LMS: mu in order of 0.0001 for acceptable convergence speed
%NLMS: mu in order of 0.01 for acceptable convergence speed
%RLS: mu is lambda -> 0.99 -> 1 (has a strong dependency on this! use a loop to find out best values)
% FFE("epochs_tr",5,"epochs_dd",2,"len_tr",2^13,"mu_dd",mu_dd,"mu_tr",mu_tr,"order",25,"sps",2,"decide",0, "adaption",adaption_method(adaption),"dd_mode",use_dd_mode);
properties
sps % usually 2
order
e
e_tr
error
len_tr
mu_tr
epochs_tr
dd_mode % 1 or 0 to set DD-mode on or off
mu_dd %weight update in dd mode
epochs_dd
constellation
L %viterbi memory length
alpha
DIR
DIR_flip
trellis_states
traceback_depth
end
methods
function obj = ML_MLSE(options)
arguments(Input)
options.sps = 2;
options.order = 15;
options.len_tr = 4096;
options.mu_tr = 0;
options.epochs_tr = 5;
options.dd_mode = 1;
options.mu_dd = 1e-5;
options.epochs_dd = 5;
options.traceback_depth = 1024;
options.L = 1
end
fn = fieldnames(options);
for n = 1:numel(fn)
obj.(fn{n}) = options.(fn{n});
end
obj.e = zeros(obj.order,1);
obj.error = 0;
end
function [X,X_viterbi] = process(obj, X, D)
% actual processing of the signal (steps 1. - 3.)
% 1 normalize RMS
X = X.normalize("mode","rms");
obj.constellation = unique(D.signal);
if length(X)/length(D) ~= obj.sps
warning('Signal length does not fit to reference!');
end
% Training Mode
n = obj.len_tr;
training = 1;
obj.equalize(X.signal, D.signal,obj.mu_tr,obj.epochs_dd,n,training);
obj.e_tr = obj.e;
% Decision Directed Mode
n = X.length;
training = 0;
[y,y_vit]=obj.equalize(X.signal, D.signal,obj.mu_dd,obj.epochs_dd,n,training);
X_viterbi = X;
X.signal = y;
X.fs = D.fs; %change sampling frequency of outgoing signal from fdac e.g. 2 sps to symbol spaced = fsym
lbdesc = [num2str(obj.order),' tap FFE'];
X = X.logbookentry(lbdesc); % append to logbook
X_viterbi.signal = y_vit;
X_viterbi.fs = D.fs; %change sampling frequency of outgoing signal from fdac e.g. 2 sps to symbol spaced = fsym
lbdesc = [num2str(obj.order),'order FFE + PF + Viterbi'];
X_viterbi = X_viterbi.logbookentry(lbdesc); % append to logbook
end
function [y,y_vit] = equalize(obj,x,d,mu,epochs,N,training)
% ==============================================================
% FFE + Whitening + ML-Based Branch Metric Estimation + Viterbi
% ==============================================================
% --- Input padding and preallocation
x = [zeros(floor(obj.order/2),1); x; zeros(obj.order,1)];
N_ = N / obj.sps;
y = zeros(N_,1);
y_white = zeros(N_,1);
for epoch = 1:epochs
% ==============================================================
% INITIALIZATION (only before final epoch and detection mode)
% ==============================================================
if epoch == epochs && ~training
% --- Parameters
S = numel(unique(d)); % alphabet size
L = obj.L; % MLSE memory
Nf = L; % filter length
Delta = ceil(L/2); % delay parameter
nStates = S^L;
nFeasible = S^(L-1)*S;
% --- Trellis mapping
obj.DIR = arburg(y-d, L);
obj.DIR_flip = flip(obj.DIR);
obj.trellis_states = reshape(unique(d),1,[]);
pre_comb_mat = repmat(obj.trellis_states, L, 1);
pre_comb_cell = mat2cell(pre_comb_mat, ones(1,L), size(pre_comb_mat,2));
combs = fliplr(combvec(pre_comb_cell{:}).');
first_sym = combs(:,1);
last_sym = combs(:,end);
nStates = size(combs,1);
% --- Valid transitions
valid = false(nStates);
for from = 1:nStates
for to = 1:nStates
if all(combs(to,2:end) == combs(from,1:end-1))
valid(to,from) = true;
end
end
end
[valid_to, valid_from] = find(valid);
% --- Noise estimation
y_ideal = conv(d(:), obj.DIR(:), "same");
sigma2 = mean(abs(y - y_ideal).^2);
inv2s2 = 1/(2*sigma2);
% --- Allocate vectors and weights
pm = zeros(nStates,1);
w = zeros(Nf,nFeasible); % filter weights per transition
b = zeros(1,nFeasible); % bias terms
v_hat = zeros(1,nFeasible);
v_tilde = zeros(1,nFeasible);
bm_vec = zeros(1,nFeasible);
zi = zeros(max(numel(obj.DIR)-1,0),1);
end
% ==============================================================
% RUNTIME LOOP
% ==============================================================
symbol = 0;
for sample = 1:obj.sps:N
symbol = symbol + 1;
% --- FFE output
U = x(obj.order+sample-1:-1:sample);
y(symbol,1) = obj.e.' * U;
% --- Decision / FFE adaptation
if training
d_hat = d(symbol);
else
[~,idx] = min(abs(y(symbol) - obj.constellation));
d_hat = obj.constellation(idx);
end
err = d_hat - y(symbol);
obj.e = obj.e + mu * (err * U);
% --- Whitening + MLSE in last epoch
if epoch == epochs && ~training
[y_white(symbol), zi] = filter(obj.DIR,1,y(symbol), zi);
k = symbol;
% --- Build Δ-delayed observation window y_k
i1 = k - Nf + 1 + Delta;
i2 = k + Delta;
buf = y_white(max(1,i1):min(length(y_white),i2));
padL = max(0,1 - i1);
padR = max(0,i2 - length(y_white));
yk = [zeros(padL,1); buf(:); zeros(padR,1)]; % Nf×1
% --- Predict branch metrics for all feasible transitions
v_hat = (yk.' * w) + b; % [1×nFeasible]
v_hat = v_hat.'; % [nFeasible×1]
% --- Extended path metrics
v_tilde = pm(valid_from) + v_hat; % [nFeasible×1]
% --- Compute branch metrics (distance)
bm_vec = -(y_white(k) - v_hat).^2 * inv2s2; % 1×nFeasible
% --- Survivor selection (vector aggregation)
pm_new_vec = pm(valid_from) + bm_vec.'; % nFeasible×1
pm_next = -inf(nStates,1);
surv_idx = zeros(nStates,1);
for t = 1:nStates
mask = (valid_to==t);
[pm_next(t), arg] = max(pm_new_vec(mask));
surv_idx(t) = valid_from(find(mask,1,'first')-1+arg);
end
pm = pm_next;
% --- Traceback
if mod(symbol,obj.traceback_depth) == 0
[~,viterbi_path(symbol)] = max(pm);
for n = symbol:-1:symbol-obj.traceback_depth+2
viterbi_path(n-1) = surv_idx(viterbi_path(n));
end
end
end
end
% --- Output reconstructed path
if epoch == epochs && ~training
y_vit = first_sym(viterbi_path);
end
end
end
end
end

View File

@@ -277,14 +277,107 @@ classdef MLSE < handle
if debug
alpha_ = alpha - min(alpha) + eps;
figure();hold on;
n = 10;
scatter(1:n,obj.trellis_states(repmat([1:numel(obj.trellis_states)]',1,n)),abs(alpha_(:,end-n+1:end)),'Marker','o','LineWidth',1);
scatter(1:n,obj.trellis_states(viterbi_path(end-n+1:end)),500,'Marker','x','LineWidth',1,'MarkerEdgeColor','green');
% scatter(1:n,data_ref(end-n+1:end),500,'Marker','x','LineWidth',1,'MarkerEdgeColor','red');
yticks(obj.trellis_states);
ylim([min(obj.trellis_states)-1 max(obj.trellis_states)+1]);
% alpha_ = alpha - min(alpha) + eps;
% figure();hold on;
% n = 10;
% scatter(1:n,obj.trellis_states(repmat([1:numel(obj.trellis_states)]',1,n)),abs(alpha_(:,end-n+1:end)),'Marker','o','LineWidth',1);
% scatter(1:n,obj.trellis_states(viterbi_path(end-n+1:end)),500,'Marker','x','LineWidth',1,'MarkerEdgeColor','green');
% % scatter(1:n,data_ref(end-n+1:end),500,'Marker','x','LineWidth',1,'MarkerEdgeColor','red');
% yticks(obj.trellis_states);
% ylim([min(obj.trellis_states)-1 max(obj.trellis_states)+1]);
%% ----- Build true path from known sequence (data_ref) -----
% Memory length used by VA (L = length(obj.DIR)-1 symbols stored in state)
L = size(combs,2); % each row of combs is the L-tap state vector
N = length(data_in);
% Map each trellis level to an index (1..M)
[~, level_to_idx] = ismember(levels, levels); %#ok<ASGLU> % identity map
[ok_ref, ref_idx] = ismember(data_ref(:).', levels);
if ~all(ok_ref)
warning('Some data_ref symbols are not in "levels". True-path build may fail.');
end
% Precompute next_state(from_state, u_idx) LUT such that:
% combs(next_state,:) == [ combs(from_state,2:end) , levels(u_idx) ]
next_state = zeros(size(combs,1), numel(levels), 'uint32');
for from = 1:size(combs,1)
prefix = combs(from,2:end); % what must match in 'to' for a valid transition
for ui = 1:numel(levels)
target = [prefix, levels(ui)];
% find the unique 'to' whose state vector equals target
to = find(all(bsxfun(@eq, combs, target), 2), 1, 'first');
if isempty(to), to = 0; end
next_state(from, ui) = to;
end
end
% Initialize true path at n=1: pick any state with last_sym == data_ref(1)
% Prefer one whose suffix matches the first available history if L>1.
cand = find(last_sym == data_ref(1));
if isempty(cand)
% fallback: choose closest in amplitude (should not happen if levels match)
[~,ix] = min(abs(last_sym - data_ref(1)));
cand = ix;
end
true_state_path = zeros(1,N,'uint32');
true_state_path(1) = cand(1);
% Propagate forward using the known inputs data_ref(n)
for n = 2:N
ui = ref_idx(n); % index of the actual transmitted level at time n
from = true_state_path(n-1);
if from==0 || ui==0
true_state_path(n) = 0;
else
true_state_path(n) = next_state(from, ui);
if true_state_path(n)==0
% Safety fallback: if no valid transition found (should not happen)
% choose any to-state whose vector matches shift+current symbol
target = [combs(from,2:end), levels(ui)];
to = find(all(bsxfun(@eq, combs, target), 2), 1, 'first');
if isempty(to), to = from; end
true_state_path(n) = to;
end
end
end
%% ----- Collect branch metrics along decoded vs. true path -----
bm_decoded = nan(1,N);
bm_true = nan(1,N);
% n=1 in your code stores pm into bm_fw(:,:,1); real BMs start at n>=2
for n = 2:N
% Decoded path: to = viterbi_path(n), from = survivor that fed it
to_d = viterbi_path(n);
from_d = pm_survivor_fw_idx(to_d, n);
bm_decoded(n) = bm_fw(to_d, from_d, n);
% True path: transition true_state_path(n-1) -> true_state_path(n)
to_t = true_state_path(n);
from_t = true_state_path(n-1);
if to_t>0 && from_t>0
bm_true(n) = bm_fw(to_t, from_t, n);
end
end
% Convert to "cost" for intuitive plotting (your BM is a log-likelihood)
cost_dec = -bm_decoded;
cost_true= -bm_true;
%% ----- Plot a short window for clarity -----
win = max(2, N-20000):N; % last 200 samples (adjust as needed)
figure('Color','w'); hold on; grid on; box on;
plot(win, cost_true(win), 'LineWidth',1.2, 'DisplayName','True path cost (BM)');
plot(win, cost_dec(win), 'LineWidth',1.2, 'DisplayName','Decoded path cost (BM)');
xlabel('Time index n'); ylabel('Branch cost'); title('Branch metrics along true vs decoded path');
legend('Location','best');
%% ----- Optional: overlay symbol levels for the same window -----
yyaxis right
plot(win, data_in(win), ':', 'LineWidth',0.8, 'DisplayName','y(n)');
ylabel('Amplitude');
end
VITERBI_ESTIMATION_SYMBOLS(1:length(data_in)) = first_sym(viterbi_path);
@@ -564,11 +657,6 @@ classdef MLSE < handle
end
function s = logsumexp(a,dim)
% returns log(sum(exp(a),dim)) safely
amax = max(a,[],dim);
s = amax + log(sum(exp(a - amax), dim));
end
end
end

146
Classes/GifWriter.m Normal file
View File

@@ -0,0 +1,146 @@
classdef GifWriter < handle
%GIFWRITER Simple class to create GIFs from figures (parallel-safe)
%
% Example:
% g = GifWriter('Name','mySim','Parallel',true);
% parfor i = 1:10
% plot(rand(10,1));
% g.addFrame(1,i);
% end
% g.compile(1);
properties
Name (1,:) char = 'default' % GIF base name
DelayTime (1,1) double = 0.1 % Frame delay in seconds
Parallel (1,1) logical = false % Enable parallel-safe mode
BaseDir (1,:) char % Base directory for temp frames
OutputDir (1,:) char % Final GIF output directory
end
methods
%% Constructor
function obj = GifWriter(varargin)
% Parse name/value pairs
p = inputParser;
addParameter(p, 'Name', 'default', @ischar);
addParameter(p, 'DelayTime', 0.1, @isnumeric);
addParameter(p, 'Parallel', false, @islogical);
addParameter(p, 'OutputDir', fullfile(pwd, 'gif_output'), @ischar);
parse(p, varargin{:});
obj.Name = p.Results.Name;
obj.DelayTime = p.Results.DelayTime;
obj.Parallel = p.Results.Parallel;
obj.OutputDir = p.Results.OutputDir;
obj.BaseDir = fullfile(obj.OutputDir, 'tmp', obj.Name);
if ~exist(obj.BaseDir, 'dir'), mkdir(obj.BaseDir); end
if ~exist(obj.OutputDir, 'dir'), mkdir(obj.OutputDir); end
end
%%
function addFrame(obj, figInput, pos)
%ADDFRAME Add a figure frame to the GIF (supports parallel mode)
%
% Usage:
% obj.addFrame(figHandle)
% obj.addFrame(figNum)
% obj.addFrame(figHandle, pos) % parallel mode
% obj.addFrame(figNum, pos)
%
% In parallel mode, 'pos' must be a unique integer (loop index).
if nargin < 3, pos = []; end
% --- Resolve figure handle ---
if isnumeric(figInput)
% User passed a figure number
if ~ishandle(figInput)
warning('GifWriter:addFrame', 'Figure %d not found.', figInput);
return;
end
figHandle = figure(figInput);
elseif isa(figInput, 'matlab.ui.Figure')
figHandle = figInput;
else
error('GifWriter:addFrame:InvalidInput', ...
'Input must be a figure handle or figure number.');
end
% --- Parallel-safe frame writing ---
if obj.Parallel
if isempty(pos)
error('GifWriter:ParallelMode', ...
'In parallel mode, provide a unique ''pos'' identifier.');
end
% Directory for this figure number
frameDir = fullfile(obj.BaseDir, sprintf('fig_%d', figHandle.Number));
if ~exist(frameDir, 'dir')
mkdir(frameDir);
end
% File path for this frame
frameFile = fullfile(frameDir, sprintf('frame_%05d.png', pos));
% Export to PNG (headless-safe)
exportgraphics(figHandle, frameFile, 'Resolution', 150);
else
% --- Serial mode: append directly to GIF ---
gifFile = fullfile(obj.OutputDir, ...
sprintf('%s_fig_%d.gif', obj.Name, figHandle.Number));
% Export frame temporarily
tmpFile = [tempname, '.png'];
exportgraphics(figHandle, tmpFile, 'Resolution', 150);
img = imread(tmpFile);
delete(tmpFile);
% Append to GIF
[A, map] = rgb2ind(img, 256);
if ~isfile(gifFile)
imwrite(A, map, gifFile, 'gif', ...
'LoopCount', Inf, 'DelayTime', obj.DelayTime);
else
imwrite(A, map, gifFile, 'gif', ...
'WriteMode', 'append', 'DelayTime', obj.DelayTime);
end
end
end
%% Compile all PNGs into a GIF (and clean up)
function compile(obj, fignum)
figDir = fullfile(obj.BaseDir, sprintf('fig_%d', fignum));
gifFile = fullfile(obj.OutputDir, sprintf('%s_fig_%d.gif', obj.Name, fignum));
frames = dir(fullfile(figDir, 'frame_*.png'));
if isempty(frames)
warning('GifWriter:NoFrames', 'No frames found for figure %d.', fignum);
return;
end
% Sort by frame name
[~, idx] = sort({frames.name});
frames = frames(idx);
% Combine into a GIF
for i = 1:numel(frames)
img = imread(fullfile(frames(i).folder, frames(i).name));
[A, map] = rgb2ind(img, 256);
if i == 1
imwrite(A, map, gifFile, 'gif', ...
'LoopCount', Inf, 'DelayTime', obj.DelayTime);
else
imwrite(A, map, gifFile, 'gif', ...
'WriteMode', 'append', 'DelayTime', obj.DelayTime);
end
end
% Clean up temporary frames
rmdir(figDir, 's');
end
end
end