Source code for pyLOM.SPOD.plots

#!/usr/bin/env python
#
# pyLOM - Python Low Order Modeling.
#
# DMD plotting utilities.
#
# Last rev: 27/10/2021
from __future__ import print_function, division

import numpy as np
import matplotlib.pyplot as plt

from .utils        import extract_modes
from ..utils       import gpu_to_cpu
from ..utils.plots import plotResidual, plotFieldStruct2D, plotSnapshot, plotLayout
from ..            import Mesh, Dataset



[docs]
def plotMode(L:np.ndarray, P:np.ndarray, freqs:np.ndarray, mesh:Mesh, dset:Dataset, ivar:int, pointData:bool=True, modes:np.ndarray=np.array([1],np.int32),**kwargs):
	r'''
	Plot a SPOD mode, including both the real and imaginary parts

	Args:
		L (np.ndarray): modal energy spectra
		P (np.ndarray): spatial SPOD modes
		freqs (np.ndarray): frequencies at which the modes are computed
		mesh (Mesh): mesh at which the data is represented
		dset (Dataset): pyLOM Dataset containing the case information
		ivar (int): index of the variable inside the dataset
		pointData(bool, optional): whether the data is represented on points or cell (default, ``True``)
		modes (np.ndarray, optinal): IDs of the modes to plot
	'''
	L, P = gpu_to_cpu(L), gpu_to_cpu(P)
	# Extract the modes to be plotted
	npoints = mesh.size(pointData)
	P_modes = extract_modes(L,P,ivar,npoints,modes=modes)
	# Add to the dataset
	dset.add_field('P_MODES',len(modes),P_modes)
	# Loop over the modes
	screenshot = kwargs.pop('screenshot',None)
	off_screen = kwargs.pop('off_screen',False)
	for imode, mode in enumerate(modes):
		if screenshot is not None: kwargs['screenshot'] = screenshot % imode
		plotLayout(mesh,dset,1,1,mode-1,vars=['P_MODES'],title='Mode %d St = %.3f' % (mode-1, np.abs(freqs[mode-1])),off_screen=off_screen,**kwargs)
	# Remove from dataset
	dset.delete('P_MODES')



[docs]
def plotSpectra(f:np.ndarray, L:np.ndarray, fig:plt.figure=None, ax:plt.axes=None):
	r'''
	Plot the frequency-enegy spectrum

	Args:
		f (np.ndarray): frequencies at which the modes are computed
		L (np.ndarray): energy of each frequency
		fig (plt.figure, optional): figure object in which the plot will be done (default: ``[]``)
		axs (plt.axes, optional): axes object in which the plot will be done (default: ``[]``)

	Returns:
		[plt.figure, plt.axes]: figure and axes objects of the plot

	'''
	L, f = gpu_to_cpu(L), gpu_to_cpu(f)
	# Get or recover axis and figure
	if fig is None:
		fig = plt.figure(figsize=(8,6),dpi=100)
	if ax is None:
		ax = fig.add_subplot(1,1,1)
	# Plot
	for ii in range(L.shape[1]):
		ax.loglog(np.sort(f), L[np.argsort(f),ii], 'o-')
	ax.set_xlabel('St')
	ax.set_ylabel(r'$\lambda_i$')
	return fig, ax