Package topo :: Package outputfns :: Module basic :: Class PoissonSample

Class PoissonSample

                                  object --+        
                                           |        
base.parameterizedobject.ParameterizedObject --+    
                                               |    
                  base.functionfamilies.OutputFn --+
                                                   |
                                                  PoissonSample

Simulate Poisson-distributed activity with specified mean values.

This output function interprets each matrix value as the (potentially scaled) rate of a Poisson process and replaces it with a sample from the appropriate Poisson distribution.

To allow the matrix to contain values in a suitable range (such as [0.0,1.0]), the input matrix is scaled by the parameter in_scale, and the baseline_rate is added before sampling. After sampling, the output value is then scaled by out_scale. The function thus performs this transformation:

x <- P(in_scale * x + baseline_rate) * out_scale

where x is a matrix value and P(r) samples from a Poisson distribution with rate r.

Nested Classes

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Inherited from base.parameterizedobject.ParameterizedObject: __metaclass__

Instance Methods

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__call__(self, x)

source code

Inherited from base.functionfamilies.OutputFn: __add__

Inherited from base.parameterizedobject.ParameterizedObject: __getstate__, __init__, __repr__, __setstate__, __str__, as_uninitialized, debug, defaults, force_new_dynamic_value, get_param_values, get_value_generator, inspect_value, message, print_param_values, script_repr, verbose, warning

Inherited from base.parameterizedobject.ParameterizedObject (private): _check_params, _instantiate_param, _set_name, _setup_params

Inherited from object: __delattr__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __setattr__

Class Methods

[hide private]

Inherited from base.parameterizedobject.ParameterizedObject: params, print_param_defaults

Class Variables

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in_scale = <topo.base.parameterclasses.Number object at 0x9db9...
Amount by which to scale the input.

baseline_rate = <topo.base.parameterclasses.Number object at 0...
Constant to add to the input after scaling, resulting in a baseline Poisson process rate.

out_scale = <topo.base.parameterclasses.Number object at 0x9db...
Amount by which to scale the output (e.g.

Inherited from base.functionfamilies.OutputFn: norm_value

Inherited from base.parameterizedobject.ParameterizedObject: name, print_level

Properties

[hide private]

Inherited from object: __class__

Method Details

[hide private]

call(self, x)
(Call operator)

source code

Overrides: base.functionfamilies.OutputFn.__call__

Class Variable Details

[hide private]

in_scale

Amount by which to scale the input.

Value:

Number(default= 1.0, doc= """
       Amount by which to scale the input.""")

baseline_rate

Constant to add to the input after scaling, resulting in a baseline Poisson process rate.

Value:

Number(default= 0.0, doc= """
       Constant to add to the input after scaling, resulting in a baseline
       Poisson process rate.""")

out_scale

Amount by which to scale the output (e.g. 1.0/in_scale).

Value:

Number(default= 1.0, doc= """
       Amount by which to scale the output (e.g. 1.0/in_scale).""")

Class PoissonSample

__call__(self, x) (Call operator)

in_scale

baseline_rate

out_scale

call(self, x)
(Call operator)