def runToyExp(datasetNames, sampleSizes, foldsSet, cvScalings, sampleMethods, numProcesses, fileNameSuffix):
dataDir = PathDefaults.getDataDir() + "modelPenalisation/toy/"
outputDir = PathDefaults.getOutputDir() + "modelPenalisation/"
svm = LibSVM()
numCs = svm.getCs().shape[0]
numGammas = svm.getGammas().shape[0]
numMethods = 1 + (1 + cvScalings.shape[0])
numParams = 2
runIdeal = True
runCv = True
runVfpen = True
for i in range(len(datasetNames)):
datasetName = datasetNames[i][0]
numRealisations = datasetNames[i][1]
logging.debug("Learning using dataset " + datasetName)
for s in range(len(sampleMethods)):
sampleMethod = sampleMethods[s][1]
outfileName = outputDir + datasetName + sampleMethods[s][0] + fileNameSuffix
fileLock = FileLock(outfileName + ".npz")
if not fileLock.isLocked() and not fileLock.fileExists():
fileLock.lock()
errors = numpy.zeros((numRealisations, len(sampleSizes), foldsSet.shape[0], numMethods))
params = numpy.zeros((numRealisations, len(sampleSizes), foldsSet.shape[0], numMethods, numParams))
errorGrids = numpy.zeros(
(numRealisations, len(sampleSizes), foldsSet.shape[0], numMethods, numCs, numGammas)
)
approxGrids = numpy.zeros(
(numRealisations, len(sampleSizes), foldsSet.shape[0], numMethods, numCs, numGammas)
)
idealGrids = numpy.zeros((numRealisations, len(sampleSizes), foldsSet.shape[0], numCs, numGammas))
data = numpy.load(dataDir + datasetName + ".npz")
gridPoints, trainX, trainY, pdfX, pdfY1X, pdfYminus1X = (
data["arr_0"],
data["arr_1"],
data["arr_2"],
data["arr_3"],
data["arr_4"],
data["arr_5"],
)
# We form a test set from the grid points
testX = numpy.zeros((gridPoints.shape[0] ** 2, 2))
for m in range(gridPoints.shape[0]):
testX[m * gridPoints.shape[0] : (m + 1) * gridPoints.shape[0], 0] = gridPoints
testX[m * gridPoints.shape[0] : (m + 1) * gridPoints.shape[0], 1] = gridPoints[m]
for j in range(numRealisations):
Util.printIteration(j, 1, numRealisations, "Realisation: ")
for k in range(sampleSizes.shape[0]):
sampleSize = sampleSizes[k]
for m in range(foldsSet.shape[0]):
folds = foldsSet[m]
logging.debug("Using sample size " + str(sampleSize) + " and " + str(folds) + " folds")
perm = numpy.random.permutation(trainX.shape[0])
trainInds = perm[0:sampleSize]
validX = trainX[trainInds, :]
validY = trainY[trainInds]
svm = LibSVM(processes=numProcesses)
# Find ideal penalties
if runIdeal:
logging.debug("Finding ideal grid of penalties")
idealGrids[j, k, m, :, :] = parallelPenaltyGridRbf(
svm, validX, validY, testX, gridPoints, pdfX, pdfY1X, pdfYminus1X
)
# Cross validation
if runCv:
logging.debug("Running V-fold cross validation")
methodInd = 0
idx = sampleMethod(folds, validY.shape[0])
if sampleMethod == Sampling.bootstrap:
bootstrap = True
else:
bootstrap = False
bestSVM, cvGrid = svm.parallelVfcvRbf(validX, validY, idx, True, bootstrap)
predY, decisionsY = bestSVM.predict(testX, True)
decisionGrid = numpy.reshape(
decisionsY, (gridPoints.shape[0], gridPoints.shape[0]), order="F"
)
errors[j, k, m, methodInd] = ModelSelectUtils.bayesError(
gridPoints, decisionGrid, pdfX, pdfY1X, pdfYminus1X
)
params[j, k, m, methodInd, :] = numpy.array([bestSVM.getC(), bestSVM.getKernelParams()])
errorGrids[j, k, m, methodInd, :, :] = cvGrid
# v fold penalisation
if runVfpen:
logging.debug("Running penalisation")
# BIC penalisation
Cv = float((folds - 1) * numpy.log(validX.shape[0]) / 2)
tempCvScalings = cvScalings * (folds - 1)
tempCvScalings = numpy.insert(tempCvScalings, 0, Cv)
# Use cross validation
idx = sampleMethod(folds, validY.shape[0])
svmGridResults = svm.parallelVfPenRbf(validX, validY, idx, tempCvScalings)
for n in range(len(tempCvScalings)):
bestSVM, trainErrors, approxGrid = svmGridResults[n]
methodInd = n + 1
predY, decisionsY = bestSVM.predict(testX, True)
decisionGrid = numpy.reshape(
decisionsY, (gridPoints.shape[0], gridPoints.shape[0]), order="F"
)
errors[j, k, m, methodInd] = ModelSelectUtils.bayesError(
gridPoints, decisionGrid, pdfX, pdfY1X, pdfYminus1X
)
params[j, k, m, methodInd, :] = numpy.array(
[bestSVM.getC(), bestSVM.getKernelParams()]
)
errorGrids[j, k, m, methodInd, :, :] = trainErrors + approxGrid
approxGrids[j, k, m, methodInd, :, :] = approxGrid
meanErrors = numpy.mean(errors, 0)
print(meanErrors)
meanParams = numpy.mean(params, 0)
print(meanParams)
meanErrorGrids = numpy.mean(errorGrids, 0)
stdErrorGrids = numpy.std(errorGrids, 0)
meanIdealGrids = numpy.mean(idealGrids, 0)
stdIdealGrids = numpy.std(idealGrids, 0)
meanApproxGrids = numpy.mean(approxGrids, 0)
stdApproxGrids = numpy.std(approxGrids, 0)
numpy.savez(
outfileName,
errors,
params,
meanErrorGrids,
stdErrorGrids,
meanIdealGrids,
stdIdealGrids,
meanApproxGrids,
stdApproxGrids,
)
logging.debug("Saved results as file " + outfileName + ".npz")
fileLock.unlock()
else:
logging.debug("Results already computed")
logging.debug("All done!")
logging.debug("Using sample size " + str(sampleSize) + " and " + str(folds) + " folds")
perm = numpy.random.permutation(trainX.shape[0])
trainInds = perm[0:sampleSize]
validX = trainX[trainInds, :]
validY = trainY[trainInds]
logging.debug("Finding ideal grid of penalties")
idealGrid = parallelPenaltyGridRbf(svm, validX, validY, testX, gridPoints, pdfX, pdfY1X, pdfYminus1X)
for s in range(len(sampleMethods)):
sampleMethod = sampleMethods[s][1]
logging.debug("Sampling method :" + str(sampleMethod))
idx = sampleMethod(folds, validY.shape[0])
svmGridResults = svm.parallelVfPenRbf(validX, validY, idx, cvScalings)
bestSVM, trainErrors, approxGrid = svmGridResults[0]
meanErrors = trainErrors + approxGrid
plt.figure(s)
plt.title("Sampling method :" + str(sampleMethod))
plt.scatter(idealGrid.flatten(), approxGrid.flatten())
plt.xlabel("Ideal penalty")
plt.ylabel("Approximate penalty")
plt.figure(s + len(sampleMethods))
plt.title("Sampling method :" + str(sampleMethod))
plt.contourf(numpy.log2(svm.gammas), numpy.log2(svm.Cs), numpy.abs(idealGrid - approxGrid), 100, antialiased=True)
plt.colorbar()
plt.xlabel("Gamma")
