corrLib

Autocorrelation functions

corrI(X, Y, I)

Compute pixel intensity spatial autocorrelation of an image.

corrS(X, Y, U, V)

Compute the spatial autocorrelations of a velocity field.

distance_corr(X, Y, C)

Convert 2d correlation matrix into 1d.

autocorr1d(x, t)

Compute the temporal autocorrelation of a 1-D signal.

vacf_piv(vstack, dt[, mode])

Compute averaged vacf from PIV data.

Density fluctuations

density_fluctuation(img8)

This is the first attempt to calculate density fluctuations in bacterial suspensions.

df2(imgstack[, size_min, step, method])

This is used for small scale test of temporal variation based density fluctuation analysis.

df2_(img_stack[, boxsize, size_min, step])

Compute number fluctuations of an image stack (3D np.array, frame*h*w)

plot_gnf(gnf_data)

Used for small scale test of gnf analysis.

local_df(img_folder[, seg_length, winsize, step])

Compute local density fluctuations of given image sequence in img_folder

Energy spectra

compute_energy_density(pivData[, d, MPP])

Compute kinetic energy density in k space from piv data.

compute_wavenumber_field(shape, d)

Compute the wave number field Kx and Ky, and magnitude field k.

energy_spectrum(pivData[, d])

Compute energy spectrum (E vs k) from pivData.

Flow field analysis

div_field(img, pivData, winsize, step)

Compute multiple divergence fields from PIV data and microscopy image.

divergence(pivData[, step, shape])

Compute divergence field based on piv data (x, y, u, v)

vorticity(pivData[, step, shape])

Compute vorticity field based on piv data (x, y, u, v)

convection(pivData, image, winsize[, step, ...])

Compute convection term u.grad(c) based on piv data (x, y, u, v) and image.

Misc

divide_windows(img[, windowsize, step])

Divide an image into windows with specified size and step.

divide_stack(img_stack[, winsize, step])

Divide image stack into several evenly spaced windows of stack.