Modules¶
Overview¶
The programs in this package are as follows:
read: read a 3-column space, comma or tab delimited text file
partition: partition a Nx3 point cloud into M windows of nx3 points with specified spacing between centroids of adjacent windows and with specified overlap between windows.
detrend: returns detrended amplitudes of a Nx3 point cloud
sgolay: returns the Savitsky-Golay digital filter of a 2D signal
spatial: calculate spatial statistics of a Nx3 point cloud
lengthscale: calculates the integral lengthscale of a Nx3 point cloud
spectral: calculate spectral statistics of a Nx3 point cloud
process: allows control of inputs to all modules (full workflow)
write: write program outputs to a comma delimited text file
test: program testing suite
plot: program utilities for creating 2d and 3d plots
These are all command-line/modular programs which take a number of input (some required, some optional). Please see the individual files for a comprehensive list of input options
Main program: process¶
Calculate spectral and spatial statistics of a Nx3 point cloud
Syntax¶
You call the function like this:
() = pysesa.process(infile, out, detrend, proctype, mxpts, res, nbin, lentype, minpts, taper, prc_overlap)
Parameters¶
- infile : str
- ASCII file containing an Nx3 point cloud in 3 columns
Other Parameters¶
- out : float, optional [default = 0.5]
- output grid resolution
- detrend : int, optional [default = 4]
type of detrending.
1 = remove mean
2 = remove Ordinary least squares plane
3 = remove Robust linear model plane
4 = remove Orthogonal Distance Regression plane
5 = remove Savitsky-Golay digital filter, order 1
- proctype : int, optional [default = 1, no spectral smoothing]
proctype type: 1 = spectral only, no spectral smoothing
2 = spectral only, spectrum smoothed with Gaussian
3 = spatial only
4 = spatial + spectrum, no spectral smoothing
5 = spatial + spectrum smoothed with Gaussian
- mxpts : float, optional [default = 1024]
- maximum number of points allowed in a window
- res : float, optional [default = 0.05]
- spatial grid resolution to create a grid
- nbin : int, optional [default = 20]
- number of bins for power spectral binning
- lentype : int, optional [default = 1, l<0.5]
lengthscale type: 1 = l<0.5
2 = l<1/e
3 = l<0
- minpts : float, optional [default = 16]
- minimum number of points allowed in a window
- taper : int, optional [default = Hanning]
- flag for taper type: 1 = Hanning (Hann) 2 = Hamming 3 = Blackman 4 = Bartlett
- prc_overlap : float, *optional” [default = 0]
- percentage overlap between windows
Returns [proctype = 1 or proctype = 2]¶
- data: list
x = centroid in horizontal coordinate
y = centroid in laterial coordinate
slope = slope of regression line through log-log 1D power spectral density
intercept = intercept of regression line through log-log 1D power spectral density
r_value = correlation of regression through log-log 1D power spectral density
p_value = probability that slope of regression through log-log 1D power spectral density is not zero
std_err = standard error of regression through log-log 1D power spectral density
d = fractal dimension
l = integral lengthscale
wmax = peak wavelength
wmean = mean wavelength
rms1 = RMS amplitude from power spectral density
rms2 = RMS amplitude from bin averaged power spectral density
Z = zero-crossings per unit length
E = extreme per unit length
sigma = RMS amplitude
T0_1 = average spatial period (m_0/m_1)
T0_2 = average spatial period (m_0/m_2)^0.5
sw1 = spectral width
sw2 = spectral width (normalised radius of gyration)
m0 = zeroth moment of spectrum
m1 = first moment of spectrum
m2 = second moment of spectrum
m3 = third moment of spectrum
m4 = fourth moment of spectrum
Returns [proctype = 3]¶
- data: list
x = centroid in horizontal coordinate
y = centroid in laterial coordinate
z_mean = centroid in amplitude
z_max = max amplitude
z_min = min amplitude
z_range = range in amplitude
sigma = standard deviation of amplitudes
skewness = skewness of amplitudes
kurtosis = skewness of amplitudes
n = number of 3D coordinates
Returns [proctype = 4 or proctype = 4]¶
- data: list
x = centroid in horizontal coordinate
y = centroid in laterial coordinate
z_mean = centroid in amplitude
z_max = max amplitude
z_min = min amplitude
z_range = range in amplitude
sigma = standard deviation of amplitudes
skewness = skewness of amplitudes
kurtosis = skewness of amplitudes
n = number of 3D coordinates
slope = slope of regression line through log-log 1D power spectral density
intercept = intercept of regression line through log-log 1D power spectral density
r_value = correlation of regression through log-log 1D power spectral density
p_value = probability that slope of regression through log-log 1D power spectral density is not zero
std_err = standard error of regression through log-log 1D power spectral density
d = fractal dimension
l = integral lengthscale
wmax = peak wavelength
wmean = mean wavelength
rms1 = RMS amplitude from power spectral density
rms2 = RMS amplitude from bin averaged power spectral density
Z = zero-crossings per unit length
E = extreme per unit length
sigma = RMS amplitude
T0_1 = average spatial period (m_0/m_1)
T0_2 = average spatial period (m_0/m_2)^0.5
sw1 = spectral width
sw2 = spectral width (normalised radius of gyration)
m0 = zeroth moment of spectrum
m1 = first moment of spectrum
m2 = second moment of spectrum
m3 = third moment of spectrum
m4 = fourth moment of spectrum
