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| author | ziejd2 | 2017-09-28 15:04:40 -0500 |
|---|---|---|
| committer | ziejd2 | 2017-09-28 15:04:40 -0500 |
| commit | 8070dc963753142bb86c4ed698d91fd623ed28e7 (patch) | |
| tree | d0f6dd8fc46a49b819aa55c1a90faa14d8448883 /sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m | |
| parent | 7cc31810d53176e805532b2789955f4eedbce6bb (diff) | |
| download | BNW-8070dc963753142bb86c4ed698d91fd623ed28e7.tar.gz | |
BNW using Octave instead of Matlab.
This version of BNW should perform the same as the original version. The only difference is that it uses Octave instead of Matlab when running BayesNet Toolbox during parameter learning. I am calling this BNW_1.02. It can be accessed at: compbio.uthsc.edu/BNW_1.02
Diffstat (limited to 'sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m')
| -rw-r--r-- | sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m b/sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m new file mode 100644 index 00000000..7e9d3f6b --- /dev/null +++ b/sourcecodes/bnt-master/BNT/CPDs/@mlp_CPD/mlp_CPD.m @@ -0,0 +1,139 @@ +function CPD = mlp_CPD(bnet, self, nhidden, w1, b1, w2, b2, clamped, max_iter, verbose, wthresh, llthresh) +% MLP_CPD Make a CPD from a Multi Layer Perceptron (i.e., feedforward neural network) +% +% We use a different MLP for each discrete parent combination (if there are any discrete parents). +% We currently assume this node (the child) is discrete. +% +% CPD = mlp_CPD(bnet, self, nhidden) +% will create a CPD with random parameters, where self is the number of this node and nhidden the number of the hidden nodes. +% The params are drawn from N(0, s*I), where s = 1/sqrt(n+1), n = length(X). +% +% CPD = mlp_CPD(bnet, self, nhidden, w1, b1, w2, b2) allows you to specify the params, where +% w1 = first-layer weight matrix +% b1 = first-layer bias vector +% w2 = second-layer weight matrix +% b2 = second-layer bias vector +% These are assumed to be the same for each discrete parent combination. +% If any of these are [], random values will be created. +% +% CPD = mlp_CPD(bnet, self, nhidden, w1, b1, w2, b2, clamped) allows you to prevent the params from being +% updated during learning (if clamped = 1). Default: clamped = 0. +% +% CPD = mlp_CPD(bnet, self, nhidden, w1, b1, w2, b2, clamped, max_iter, verbose, wthresh, llthresh) +% alllows you to specify params that control the M step: +% max_iter - the maximum number of steps to take (default: 10) +% verbose - controls whether to print (default: 0 means silent). +% wthresh - a measure of the precision required for the value of +% the weights W at the solution. Default: 1e-2. +% llthresh - a measure of the precision required of the objective +% function (log-likelihood) at the solution. Both this and the previous condition must +% be satisfied for termination. Default: 1e-2. +% +% For learning, we use a weighted version of scaled conjugated gradient in the M step. + +if nargin==0 + % This occurs if we are trying to load an object from a file. + CPD = init_fields; + CPD = class(CPD, 'mlp_CPD', discrete_CPD(0,[])); + return; +elseif isa(bnet, 'mlp_CPD') + % This might occur if we are copying an object. + CPD = bnet; + return; +end +CPD = init_fields; + +assert(myismember(self, bnet.dnodes)); +ns = bnet.node_sizes; + +ps = parents(bnet.dag, self); +dnodes = mysetdiff(1:length(bnet.dag), bnet.cnodes); +dps = myintersect(ps, dnodes); +cps = myintersect(ps, bnet.cnodes); +dpsz = prod(ns(dps)); +cpsz = sum(ns(cps)); +self_size = ns(self); + +% discrete/cts parent index - which ones of my parents are discrete/cts? +CPD.dpndx = find_equiv_posns(dps, ps); +CPD.cpndx = find_equiv_posns(cps, ps); + +CPD.mlp = cell(1,dpsz); +for i=1:dpsz + CPD.mlp{i} = mlp(cpsz, nhidden, self_size, 'softmax'); + if nargin >=4 & ~isempty(w1) + CPD.mlp{i}.w1 = w1; + end + if nargin >=5 & ~isempty(b1) + CPD.mlp{i}.b1 = b1; + end + if nargin >=6 & ~isempty(w2) + CPD.mlp{i}.w2 = w2; + end + if nargin >=7 & ~isempty(b2) + CPD.mlp{i}.b2 = b2; + end + W1app(:,:,i)=CPD.mlp{i}.w1; + W2app(:,:,i)=CPD.mlp{i}.w2; + b1app(i,:)=CPD.mlp{i}.b1; + b2app(i,:)=CPD.mlp{i}.b2; +end +if nargin < 8, clamped = 0; end +if nargin < 9, max_iter = 10; end +if nargin < 10, verbose = 0; end +if nargin < 11, wthresh = 1e-2; end +if nargin < 12, llthresh = 1e-2; end + +CPD.self = self; +CPD.max_iter = max_iter; +CPD.verbose = verbose; +CPD.wthresh = wthresh; +CPD.llthresh = llthresh; + +% sufficient statistics +% Since MLP is not in the exponential family, we must store all the raw data. +% +CPD.W1=W1app; % Extract all the parameters of the node for handling discrete obs parents +CPD.W2=W2app; % +nparaW=[size(W1app) size(W2app)]; % +CPD.b1=b1app; % +CPD.b2=b2app; % +nparab=[size(b1app) size(b2app)]; % + +CPD.sizes=bnet.node_sizes(:); % used in CPD_to_table to pump up the node sizes + +CPD.parent_vals = []; % X(l,:) = value of cts parents in l'th example + +CPD.eso_weights=[]; % weights used by the SCG algorithm + +CPD.self_vals = []; % Y(l,:) = value of self in l'th example + +% For BIC +CPD.nsamples = 0; +CPD.nparams=prod(nparaW)+prod(nparab); +CPD = class(CPD, 'mlp_CPD', discrete_CPD(clamped, ns([ps self]))); + +%%%%%%%%%%% + +function CPD = init_fields() +% This ensures we define the fields in the same order +% no matter whether we load an object from a file, +% or create it from scratch. (Matlab requires this.) + +CPD.mlp = {}; +CPD.self = []; +CPD.max_iter = []; +CPD.verbose = []; +CPD.wthresh = []; +CPD.llthresh = []; +CPD.approx_hess = []; +CPD.W1 = []; +CPD.W2 = []; +CPD.b1 = []; +CPD.b2 = []; +CPD.sizes = []; +CPD.parent_vals = []; +CPD.eso_weights=[]; +CPD.self_vals = []; +CPD.nsamples = []; +CPD.nparams = []; |
