1.4.0 release

.github/workflows/docker-image.yml

@@ -15,8 +15,10 @@ jobs:
         registry: ghcr.io
         username: ${{github.actor}}
         password: ${{secrets.GITHUB_TOKEN}}
-    - name: Build and push
-      run: |
-        docker build . --tag ghcr.io/LemurPwned/cmtj:latest
-        docker push ghcr.io/LemurPwned/cmtj:latest
-
+    - name: Build and push image
+      uses: docker/build-push-action@v2
+      with:
+        push: true
+        file: docker/Dockerfile
+        tags: |
+          ghcr.io/lemurpwned/cmtj:latest

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Python wheels manylinux stable build
         uses: RalfG/[email protected]
         with:

.github/workflows/python-test.yml

@@ -8,10 +8,10 @@ on:
     branches: [ "master" ]
   pull_request:
     branches: [ "master" ]
+  workflow_dispatch:
 
 jobs:
-  build:
-
+  build-linux:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: true
@@ -33,3 +33,26 @@ jobs:
     - name: Test with pytest
       run: |
         pytest
+
+  build-windows:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: true
+      matrix:
+        python-version: ["3.9", "3.10", "3.11"]
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install flake8 pytest
+        python -m pip install -e .[utils,test]
+
+    - name: Test with pytest
+      run: |
+        pytest

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+# 1.4.0
+
+- Adding new, dynamic symbolic model compatible with `Solver` class. It is now possible to use the `Solver` class with `LayerDynamic` to solve the LLG equation.
+- Added tests for procedures and operators.
+- Added missing operators for `CVector` class in Python.
+- `CVector` is now subscriptable.
+- Added new `CVector` and `AxialDriver` initialisations.
+- `VSD` and `PIMM` procedures accept additional new parameters.
+- Added some optimization utilities like `coordinate_descent`.
+- Added a `streamlit` service for an example PIMM simulation.
+
 # 1.3.2
 
 - Added new `ScalarDrivers` -- Gaussian impulse and Gaussian step.

README.md

@@ -6,6 +6,7 @@
 [![pages-build-deployment](https://github.com/LemurPwned/cmtj/actions/workflows/pages/pages-build-deployment/badge.svg?branch=gh-pages)](https://github.com/LemurPwned/cmtj/actions/workflows/pages/pages-build-deployment)
 [![Version](https://img.shields.io/pypi/v/cmtj)](https://pypi.org/project/cmtj/)
 [![License](https://img.shields.io/pypi/l/cmtj.svg)](https://github.com/LemurPwned/cmtj/blob/master/LICENSE)
+[![Streamlit](https://static.streamlit.io/badges/streamlit_badge_black_white.svg)](http://cmtj-simulations.streamlit.app/)
 ![Downloads](https://img.shields.io/pypi/dm/cmtj.svg)
 
 ## Short description
@@ -14,6 +15,10 @@ A name may be misleading -- the MTJ (Magnetic Tunnel Junctions) are not the only
 The library allows for macromagnetic simulation of various multilayer spintronic structures. The package uses C++ implementation of (s)LLGS (stochastic Landau-Lifschitz-Gilbert-Slonczewski) equation with various field contributions included for instance: anisotropy, interlayer exchange coupling, demagnetisation, dipole fields etc.
 It is also possible to connect devices in parallel or in series to have electrically coupled arrays.
 
+## Demo
+
+Check out the [streamlit hosted demo here](http://cmtj-simulations.streamlit.app/).
+
 ## Quickstart
 
 #### Installation :rocket:
@@ -97,6 +102,11 @@ Many thanks to professor Jack Sankey for his help with the development of therma
 
 All contributions are welcome, please leave an issue if you've encountered any trouble with setup or running the library.
 
+## Docker
+
+In the `docker` directory there's a `Dockerfile` that can be used to build a docker image with the library installed.
+`Dockerfile.app` is used for streamlit development.
+
 ## Precommit
 
 There's a `.pre-commit-config.yaml` that does some basic python and cpp lints and checks. More static analysis to come in the future.

cmtj/models/__init__.py

@@ -0,0 +1,8 @@
+from .general_sb import LayerDynamic, LayerSB, Solver, VectorObj
+
+__all__ = [
+    "LayerSB",
+    "LayerDynamic",
+    "Solver",
+    "VectorObj",
+]

cmtj/models/ensemble.py

@@ -47,5 +47,5 @@ def mixed_lorentz(H, dH, Hr, Va, Vas):
     :param Vs: amplitude of symmetric Lorentzian
     :param Vas: amplitude of antisymmetric Lorentzian
     """
-    return symmetric_lorentz(H, dH, Hr,
-                             Va) + Vb * antisymmetric_lorentz(H, dH, Hr, Vas)
+    return symmetric_lorentz(H, dH, Hr, Va) + antisymmetric_lorentz(
+        H, dH, Hr, Vas)

cmtj/models/general_sb.py

@@ -13,6 +13,8 @@
 from ..utils import VectorObj, gamma, gamma_rad, mu0, perturb_position
 from ..utils.solvers import RootFinder
 
+EPS = np.finfo('float64').resolution
+
 
 def real_deocrator(fn):
     """Using numpy real cast is way faster than sympy."""
@@ -24,9 +26,11 @@ def wrap_fn(*args):
 
 
 @njit
-def fast_norm(x):
+def fast_norm(x):  # sourcery skip: for-index-underscore, sum-comprehension
     """Fast norm function for 1D arrays."""
-    sum_ = sum(x_**2 for x_ in x)
+    sum_ = 0
+    for x_ in x:
+        sum_ += x_**2
     return math.sqrt(sum_)
 
 
@@ -41,15 +45,22 @@ def general_hessian_functional(N: int):
         # indx_i = str(i + 1) # for display purposes
         indx_i = str(i)
         all_symbols.extend(
-            (sym.Symbol(r"\theta_" + indx_i), sym.Symbol(r"\phi_" + indx_i))
-        )
+            (sym.Symbol(r"\theta_" + indx_i), sym.Symbol(r"\phi_" + indx_i)))
     energy_functional_expr = sym.Function("E")(*all_symbols)
     return get_hessian_from_energy_expr(
         N, energy_functional_expr), energy_functional_expr
 
 
 @lru_cache
 def get_hessian_from_energy_expr(N: int, energy_functional_expr: sym.Expr):
+    """
+    Computes the Hessian matrix of the energy functional expression with respect to the spin angles and phases.
+
+    :param N (int): The number of spins.
+    :param energy_functional_expr (sympy.Expr): The energy functional expression.
+
+    returns: sympy.Matrix: The Hessian matrix of the energy functional expression.
+    """
     hessian = [[0 for _ in range(2 * N)] for _ in range(2 * N)]
     for i in range(N):
         # indx_i = str(i + 1) # for display purposes
@@ -155,7 +166,7 @@ def __post_init__(self):
             raise ValueError("Only up to 10 layers supported.")
         self.theta = sym.Symbol(r"\theta_" + str(self._id))
         self.phi = sym.Symbol(r"\phi_" + str(self._id))
-        self.m = sym.Matrix([
+        self.m = sym.ImmutableMatrix([
             sym.sin(self.theta) * sym.cos(self.phi),
             sym.sin(self.theta) * sym.sin(self.phi),
             sym.cos(self.theta)
@@ -169,7 +180,8 @@ def get_m_sym(self):
         """Returns the magnetisation vector."""
         return self.m
 
-    def symbolic_layer_energy(self, H: sym.Matrix, J1top: float,
+    @lru_cache(3)
+    def symbolic_layer_energy(self, H: sym.ImmutableMatrix, J1top: float,
                               J1bottom: float, J2top: float, J2bottom: float,
                               top_layer: "LayerSB", down_layer: "LayerSB"):
         """Returns the symbolic expression for the energy of the layer.
@@ -191,12 +203,14 @@ def symbolic_layer_energy(self, H: sym.Matrix, J1top: float,
                 other_m) - (J2bottom / self.thickness) * m.dot(other_m)**2
         return eng_non_interaction + top_iec_energy + bottom_iec_energy
 
-    def no_iec_symbolic_layer_energy(self, H: sym.Matrix):
+    def no_iec_symbolic_layer_energy(self, H: sym.ImmutableMatrix):
         """Returns the symbolic expression for the energy of the layer.
         Coupling contribution comes only from the bottom layer (top-down crawl)"""
         m = self.get_m_sym()
 
-        alpha = sym.Matrix([sym.cos(self.Kv.phi), sym.sin(self.Kv.phi), 0])
+        alpha = sym.ImmutableMatrix(
+            [sym.cos(self.Kv.phi),
+             sym.sin(self.Kv.phi), 0])
 
         field_energy = -mu0 * self.Ms * m.dot(H)
         surface_anistropy = (-self.Ks +
@@ -208,10 +222,49 @@ def sb_correction(self):
         omega = sym.Symbol(r'\omega')
         return (omega / gamma) * self.Ms * sym.sin(self.theta) * self.thickness
 
+    def __hash__(self) -> int:
+        return hash(str(self))
+
+    def __eq__(self, __value: "LayerSB") -> bool:
+        return self._id == __value._id and self.thickness == __value.thickness and self.Kv == __value.Kv and self.Ks == __value.Ks and self.Ms == __value.Ms
+
 
 @dataclass
-class SolverSB:
-    layers: List[LayerSB]
+class LayerDynamic(LayerSB):
+    alpha: float
+
+    def rhs_llg(self, H: sym.Matrix, J1top: float, J1bottom: float,
+                J2top: float, J2bottom: float, top_layer: "LayerSB",
+                down_layer: "LayerSB"):
+        """Returns the symbolic expression for the RHS of the spherical LLG equation.
+        Coupling contribution comes only from the bottom layer (top-down crawl)"""
+        U = self.symbolic_layer_energy(H,
+                                       J1top=J1top,
+                                       J1bottom=J1bottom,
+                                       J2top=J2top,
+                                       J2bottom=J2bottom,
+                                       top_layer=top_layer,
+                                       down_layer=down_layer)
+        # sum all components
+        prefac = gamma_rad / (1. + self.alpha)**2
+        inv_sin = 1. / (sym.sin(self.theta) + EPS)
+        dUdtheta = sym.diff(U, self.theta)
+        dUdphi = sym.diff(U, self.phi)
+
+        dtheta = (-inv_sin * dUdphi - self.alpha * dUdtheta)
+        dphi = (inv_sin * dUdtheta - self.alpha * dUdphi * (inv_sin)**2)
+        return prefac * sym.ImmutableMatrix([dtheta, dphi]) / self.Ms
+
+    def __eq__(self, __value: "LayerDynamic") -> bool:
+        return super().__eq__(__value) and self.alpha == __value.alpha
+
+    def __hash__(self) -> int:
+        return super().__hash__()
+
+
+@dataclass
+class Solver:
+    layers: List[Union[LayerSB, LayerDynamic]]
     J1: List[float]
     J2: List[float]
     H: VectorObj = None
@@ -225,7 +278,8 @@ def __post_init__(self):
         id_sets = {layer._id for layer in self.layers}
         ideal_set = set(range(len(self.layers)))
         if id_sets != ideal_set:
-            raise ValueError("Layer ids must be 0, 1, 2, ... and unique")
+            raise ValueError("Layer ids must be 0, 1, 2, ... and unique."
+                             "Ids must start from 0.")
 
     def get_layer_references(self, layer_indx, interaction_constant):
         """Returns the references to the layers above and below the layer
@@ -243,8 +297,26 @@ def get_layer_references(self, layer_indx, interaction_constant):
             1], interaction_constant[layer_indx -
                                      1], interaction_constant[layer_indx]
 
+    def compose_llg_jacobian(self, H: VectorObj):
+        """Create a symbolic jacobian of the LLG equation in spherical coordinates."""
+        # has order theta0, phi0, theta1, phi1, ...
+        if isinstance(H, VectorObj):
+            H = sym.ImmutableMatrix(H.get_cartesian())
+
+        symbols, fns = [], []
+        for i, layer in enumerate(self.layers):
+            symbols.extend((layer.theta, layer.phi))
+            top_layer, bottom_layer, Jtop, Jbottom = self.get_layer_references(
+                i, self.J1)
+            _, _, J2top, J2bottom = self.get_layer_references(i, self.J2)
+            fns.append(
+                layer.rhs_llg(H, Jtop, Jbottom, J2top, J2bottom, top_layer,
+                              bottom_layer))
+        jac = sym.ImmutableMatrix(fns).jacobian(symbols)
+        return jac, symbols
+
     def create_energy(self,
-                      H: Union[VectorObj, sym.Matrix] = None,
+                      H: Union[VectorObj, sym.ImmutableMatrix] = None,
                       volumetric: bool = False):
         """Creates the symbolic energy expression.
 
@@ -257,7 +329,7 @@ def create_energy(self,
         """
         if H is None:
             h = self.H.get_cartesian()
-            H = sym.Matrix(h)
+            H = sym.ImmutableMatrix(h)
         energy = 0
         if volumetric:
             # volumetric energy -- DO NOT USE IN GENERAL
@@ -327,7 +399,7 @@ def create_energy_hessian(self, equilibrium_position: List[float]):
                     hessian[2 * i + 1][2 * j] = expr
                     hessian[2 * j][2 * i + 1] = expr
 
-        hes = sym.Matrix(hessian)
+        hes = sym.ImmutableMatrix(hessian)
         _, U, _ = hes.LUdecomposition()
         return U.det().subs(subs)
 
@@ -338,7 +410,8 @@ def get_gradient_expr(self, accel="math"):
         symbols = []
         for layer in self.layers:
             (theta, phi) = layer.get_coord_sym()
-            grad_vector.extend((sym.diff(energy, theta), sym.diff(energy, phi)))
+            grad_vector.extend((sym.diff(energy, theta), sym.diff(energy,
+                                                                  phi)))
             symbols.extend((theta, phi))
         return sym.lambdify(symbols, grad_vector, accel)
 
@@ -417,7 +490,8 @@ def solve(self,
               perturbation: float = 1e-3,
               ftol: float = 0.01e9,
               max_freq: float = 80e9,
-              force_single_layer: bool = False):
+              force_single_layer: bool = False,
+              force_sb: bool = False):
         """Solves the system.
         1. Computes the energy functional.
         2. Computes the gradient of the energy functional.
@@ -435,6 +509,11 @@ def solve(self,
         :param pertubarion: the perturbation to use for the numerical gradient computation.
         :param ftol: tolerance for the frequency search. [numerical only]
         :param max_freq: maximum frequency to search for. [numerical only]
+        :param force_single_layer: whether to force the computation of the frequencies
+                                   for each layer individually.
+        :param force_sb: whether to force the computation of the frequencies.
+                        Takes effect only if the layers are LayerDynamic, not LayerSB.
+        :return: equilibrium position and frequencies in [GHz] (and eigenvectors if LayerDynamic instead of LayerSB).
         """
         if self.H is None:
             raise ValueError(
@@ -447,9 +526,12 @@ def solve(self,
             first_momentum_decay=first_momentum_decay,
             second_momentum_decay=second_momentum_decay,
             perturbation=perturbation)
+        if not force_sb and isinstance(self.layers[0], LayerDynamic):
+            eigenvalues, eigenvectors = self.dynamic_layer_solve(eq)
+            return eq, eigenvalues / 1e9, eigenvectors
         N = len(self.layers)
         if N == 1:
-            return eq, self.single_layer_resonance(0, eq) / 1e9
+            return eq, [self.single_layer_resonance(0, eq) / 1e9]
         if force_single_layer:
             frequencies = []
             for indx in range(N):
@@ -458,6 +540,20 @@ def solve(self,
             return eq, frequencies
         return self.num_solve(eq, ftol=ftol, max_freq=max_freq)
 
+    def dynamic_layer_solve(self, eq: List[float]):
+        """Return the FMR frequencies and modes for N layers using the
+        dynamic RHS model
+        :param eq: the equilibrium position of the system.
+        :return: frequencies and eigenmode vectors."""
+        jac, symbols = self.compose_llg_jacobian(self.H)
+        subs = {symbols[i]: eq[i] for i in range(len(eq))}
+        jac = jac.subs(subs)
+        jac = np.asarray(jac, dtype=np.float32)
+        eigvals, eigvecs = np.linalg.eig(jac)
+        eigvals_im = np.imag(eigvals) / (2 * np.pi)
+        indx = np.argwhere(eigvals_im > 0).ravel()
+        return eigvals_im[indx], eigvecs[indx]
+
     def num_solve(self,
                   eq: List[float],
                   ftol: float = 0.01e9,