I am very new in using MALLET. I need to have a library of HMM for sequence labelling task. I already look at Sequence Tagging Developer's Guide, but i am unable to understand that how can I train HMM. I have a list of Hidden States, a list of observation symbols, initial probability matrix, transition probability matrix and emission probability matrix. I need to train HMM by using B-W algorithm, to re-estimate the parameters and then want to perform sequence labelling task using those parameters.
As example, I have the following values:
hidden_states = ('Rainy', 'Sunny')
observation_symbols = ('walk', 'shop', 'clean')
initial_probability = {'Rainy': 0.6, 'Sunny': 0.4}
transition_probability = {
'Rainy' : {'Rainy': 0.7, 'Sunny': 0.3},
'Sunny' : {'Rainy': 0.4, 'Sunny': 0.6},
}
emission_probability = {
'Rainy' : {'walk': 0.1, 'shop': 0.4, 'clean': 0.5},
'Sunny' : {'walk': 0.6, 'shop': 0.3, 'clean': 0.1},
}
observation_sequence = {
walk clean shop,
clean walk shop
}
How can I train HMM using the above parameters? Please help.
Related
Right now I am doing a parameter sweep and I am trying to convert my data to a 3D graph to show the results in a very nice fashion. The problem is that I don't quite know how to plot it as I am having an issue with the result variable.
mute_rate = [0.5, 0.25, 0.125, 0.0625, 0.03125, 0.015625]
mute_step = linspace(-2.5, 2.5, 6)
results = [949.58, 293.53, 57.69, 53.65, 293.41, 1257.49;
279.19, 97.94, 32.60, 29.52, 90.52, 286.94;
32.96, 28.06, 19.56, 6.44, 13.47, 55.80;
2.01, 1.52, 5.38, 1.00, 0.89, 1.41;
0.61, 0.01, 18.59, 0.03, 0.56, 1.22;
1.85, 1.51, 18.64, 18.57, 18.54, 6.90]
So the first row in the result variable presents the results of the mute rate and mute step performed on the population from my genetic algorithm. For example:
0.5, -2.5 = 949.58,
0.5, -1.5 = 293.53,
0.5, -0.5 = 57.69
etc
It sounds like you want something akin to:
mesh(mute_step, mute_rate, results);
shading interp;
Other styles of plot would be surf or pcolor (for a 2d view).
Suppose we have the following codes for unsupervised classification. My goal is to identify the water bodies across the area. How can I mask out other classes (clusters) and only map one of the clusters (water bodies)in my results:
// Load a pre-computed Landsat composite for input
var input = ee.Image('LANDSAT/LE7_TOA_1YEAR/2001');
// Define a region in which to generate a sample of the input.
var region = ee.Geometry.Rectangle(29.7, 30, 32.5, 31.7);
// Display the sample region.
Map.setCenter(31.5, 31.0, 8);
Map.addLayer(ee.Image().paint(region, 0, 2), {}, 'region');
// Make the training dataset.
var training = input.sample({
region: region,
scale: 30,
numPixels: 5000
});
// Instantiate the clusterer and train it.
var clusterer = ee.Clusterer.wekaKMeans(5).train(training);
// Cluster the input using the trained clusterer.
var result = input.cluster(clusterer);
// Display the clusters with random colors.
Map.addLayer(result.randomVisualizer(), {}, 'clusters');
I only need the cluster (0) so I could mask the rest of the classes using the codes below:
// showing only one cluster.
var subset = result.select("cluster").eq(0).selfMask();
I would like to know how to calculate the survival probabilities in pyspark with the AFTSurvivalRegression method. I have seen this example on the web:
from pyspark.ml.regression import AFTSurvivalRegression
from pyspark.ml.linalg import Vectors
training = spark.createDataFrame([
(1.218, 1.0, Vectors.dense(1.560, -0.605)),
(2.949, 0.0, Vectors.dense(0.346, 2.158)),
(3.627, 0.0, Vectors.dense(1.380, 0.231)),
(0.273, 1.0, Vectors.dense(0.520, 1.151)),
(4.199, 0.0, Vectors.dense(0.795, -0.226))], ["label", "censor", "features"])
quantileProbabilities = [0.3, 0.6]
aft = AFTSurvivalRegression(quantileProbabilities=quantileProbabilities,
quantilesCol="quantiles")
model = aft.fit(training)
# Print the coefficients, intercept and scale parameter for AFT survival regression
print("Coefficients: " + str(model.coefficients))
print("Intercept: " + str(model.intercept))
print("Scale: " + str(model.scale))
model.transform(training).show(truncate=False)
But with this I can only predict the survival times. I also can get quantile probabilities but I do not know exactly how them work. My question is how can I get the probability of one person will survive at specific time?
In ARKit, when I perform a hit-test, I get back an instance of ARHitTestResult. One of the properties of this is worldTransform, which I understand contains a 4x4 transformation matrix of the position of the object – simd_float4x4.
As someone who is very unfamiliar with linear algebra and 3D graphics, how would I edit this matrix to, say, increase its y coordinate by 0.05?
If there is a blog post or something I could look at that would help me wrap my head around this, please let me know. I am not sure what terms I should be googling.
Sorry if my question is full of misunderstandings! As you can probably tell, I am not too familiar with these concepts.
Thank you to anyone who helps.
EDIT: The original question is best addressed by just adding 0.05 to the y component of the node's position. However, the original answer below does address a bit about composing transformation matrices, if that is something you are interested in.
======================================================================
If you want to apply an operation to a matrix, the most immediately simple way is to make a matrix that does that operation, and then multiply your original matrix by that new matrix.
For a translation, assuming you want to translate by x, y, z, you can do this:
let translation = simd_float4x4(
float4(1, 0, 0, 0),
float4(0, 1, 0, 0),
float4(0, 0, 1, 0),
float4(x, y, z, 1)
)
Note that this is just an identity matrix (1 down the diagonal) with the last column (!!!important, the float4s above are COLUMNS, not ROWS, as they would visually seem) set to contain the x/y/z values. You can research further into homogeneous coordinates, but think of this as just how a translation is represented.
Then, in simd, just do this: let newWorldTransform = translation * oldWorldTransform and you will have the old world transform translated by your x/y/z translation values (in your example, [x, y, z] = [0, 0.05, 0]).
However, it may be worth exploring why you want to edit your hit test results. I cannot think of a practical use case for that, so maybe if you explain a bit more about what you are trying to do I could suggest a more intuitive way to do it.
Matrices in 3D graphics is a regular way to translate, rotate, scale and shear 3D objects. In ARKit, RealityKit and SceneKit for consistent linear transformations you need to use simd_float4x4-like matrices:
var myMatrix: simd_float4x4
Translation 4x4 Matrix has 16 elements inside – 4 elements (float4) by 4 columns. Columns indices are 0, 1, 2 and 3. Translation matrix uses the fourth column with index 3.
SceneKit example
Use the following code to place your model 25 cm above its default position SCNVector3(0,0,0):
let sphereNode = SCNNode()
sphereNode.geometry = SCNSphere(radius: 1.0)
sphereNode.geometry?.firstMaterial?.diffuse.contents = UIColor.red
scene.rootNode.addChildNode(sphereNode)
var translation = matrix_identity_float4x4
translation.columns.3.y = 0.25
sphereNode.simdWorldTransform = translation
RealityKit example
let model = ModelEntity(mesh: .generateBox(size: 0.3))
let anchor = AnchorEntity()
anchor.addChild(model)
let currentMatrix = anchor.transform.matrix
var positionMatrix = simd_float4x4()
positionMatrix.columns.3.y = 0.25
let transform = simd_mul(currentMatrix, positionMatrix)
anchor.move(to: transform, relativeTo: model, duration: 1.0)
Im using shutterstock rickshaw chart library to visualize some sensordata via ajax-php-sql.
In all examples, rickshaw relies on data for the series in the form
[ [ { x: xval1, y: yval1}, { x: xval2, y: yval2}, ...]
[ { x: xval1, y: yvalS2_1}, { x: xval2, y: yvalS2_2}, ...]
]
which I find a bit tedious compared to e.g. xmgrace's 'nxy' mode:
one x-column, n y-columns - which is exactly what I get from the sql query (because my sensors are sampled at identic timestamps).
So the question would be is it possible to privide rickshaw's data input always the same x-data vector and individual y-data vectors, held in an array?
Thank You!
Alex