Hitachi

Hitachi has developed the CMOS annealing machine, a non-Neumann architecture computer utilizing the structure of SRAM, a storage device, to perform optimization processing with the Ising model.

Solvers

Models	Backend
BinaryQuadraticModel, HitachiModelList	hitachi.cmos_annealer

You can specify the type of machine type to run the process from the following options (see the Hitachi API Reference for more details) and HitachiParameterModel for details on how to set the type:

• 3 : GPU 32bit(int)
• 4 : GPU 32bit(float)
• 5 : ASIC 4bit

Binary Quadratic Model

import strangeworks as sw

from strangeworks_optimization import StrangeworksOptimizer
from strangeworks_optimization_models.parameter_models import HitachiParameterModel
from dimod import BinaryQuadraticModel

sw.authenticate('your-api-key')

linear = {1: -2, 2: -2, 3: -3, 4: -3, 5: -2}
quadratic = {(1, 2): 2, (1, 3): 2, (2, 4): 2, (3, 4): 2, (3, 5): 2, (4, 5): 2}
model = BinaryQuadraticModel(linear, quadratic, "BINARY")

options = HitachiParameterModel(solver_type=5)

solver = 'hitachi.cmos_annealer'

so = StrangeworksOptimizer(
    model=model,
    options=options,
    solver=solver
)

sw_job = so.run()
print(f"Job slug: {sw_job.slug}")
print(f"Job status: {so.status(sw_job.slug)}")
results = so.results(sw_job.slug)
print(results.solution)

Ising Model

The model parameter is an array of integer values [x0, y0, x1, y1, p] with 5 elements representing the vertices or interactions of the Ising model. The order in which they are specified does not affect the calculation results.

x and y represent the coordinates (x-axis, y-axis) on the Ising model, respectively, and p represents the coefficient. Set the Ising model in the form x0 == x1, y0 == y1 to represent the vertex = first order term (magnetic field), and set x0, y0 and x1, y1 to be adjacent to each other to represent the interaction of two vertices.

Adjacent means up-down, left-right, and diagonal. An error occurs if the coordinate specification of two non-adjacent vertices is included.

import strangeworks as sw

from strangeworks_optimization import StrangeworksOptimizer
from strangeworks_optimization_models.problem_models import HitachiModelList
from strangeworks_optimization_models.parameter_models import HitachiParameterModel

sw.authenticate('your-api-key')

model = HitachiModelList(
    [
        [0, 0, 0, 1, 117],
        [0, 0, 1, 0, 104],
        [0, 0, 1, 1, 65],
        [0, 1, 1, 0, 72],
        [0, 1, 1, 1, 45],
        [1, 0, 1, 1, 40],
    ]
)

options = HitachiParameterModel(solver_type=5)

solver = 'hitachi.cmos_annealer'

so = StrangeworksOptimizer(
    model=model,
    options=options,
    solver=solver
)

sw_job = so.run()
print(f"Job slug: {sw_job.slug}")
print(f"Job status: {so.status(sw_job.slug)}")
results = so.results(sw_job.slug)
print(results.solution)

HitachiParameterModel

Key	Description	Data Type	Minimum Value	Maximum Value	Default Value
type	Execution machine type	integer	-	-	3
num_executions	Annealing execution count	integer	1	10	1
parameters	Execution parameter control setting	object	-	-	-
temperature_num_steps	Temperature change step number	integer	1	100	10
temperature_step_length	Length per temperature step	integer	1	1000	100
temperature_initial	Initial temperature	number	0 or more	3.402823e+38	10.0
temperature_target	Final temperature	number	0 or more	3.402823e+38	0.01
outputs	Control of values included in response	object	-	-	-
energies	Output energy value	boolean	-	-	true
spins	Output spin value array	boolean	-	-	true
execution_time	Output execution time (nsec)	boolean	-	-	false
num_outputs	Number of outputs of spin value and energy value	integer	0	The maximum specified value is the number of times of num_executions of the request.	0
averaged_spins	Output average value per site of spin	boolean	-	-	false
averaged_energy	Output the average value of energy	boolean	-	-	false