| minmax |
Report
extreme values for each column in table data files and
optionally find the extent of the first n columns rounded
to the nearest multiple of the supplied increments |
| psrose |
Plot
sectors (length, azimuth) as windrose diagrams or polar
histograms. |
| spectrum1d |
Compute various spectral estimates from time-series, supplied
values are used as a timeseries sampled at equal specified
intervals. It will create auto/cross spectral density estimates
by Welch's method of ensemble averaging of multiple overlapped
windows, using standard error estimates from Bendat and Piersol,
and output a file with frequency (or wavelength), spectral
density estimates and standard deviation error bar size columns. |
| trend1d |
Fits
polynomial or Fourier trends to y=ƒ(x) series;
fits x,y,w values to a polynomial or Fourier regression
model where y = f(x) + e by weighted leasted squares. The
fit may be more robust by iterative reweighting. |
| trend2d |
Fits
polynomial trends to z=ƒ(x,y) series; fits x,y,z,w
values to a polynomial or Fourier regression model where
z = f(x,y) + e by weighted leasted squares. The fit may
be more robust by iterative reweighting. |
| grdtrack |
Sampling
of 2-D gridded data set along 1-D track; it uses bicubic
or bilinear interpolation of the grid at positions in the
specified table (the x,y positions in the first two column)
and writes out a new table with the interpolated values
added as a new column. |
| grdtrend |
Fit
and/or removes low-order polynomial trends to .grd files
by (optionally weighted) least squares. |
| grdvector |
Plots 2-D .grd vector fields; it reads two 2-D .grd files
which represents the x- and y- components of a vector field
and produces a vector field plot by drawing vectors with
orientation and length accordingly. |
| grdhisteq |
Histogram
equalization for gridded files; it allows the user to find
the data values which divide a given .grd file into patches
of equal area, e.g. write a .grd file with statistics based
on some kind of cumulative distribution function. |
| pshistogram |
Plot
a histogram; it calculates histogram parameters based on
the bin-width provided. Using these parameters, scaling,
and optional range parameters it will plot a histogram.
A cumulative histogram may also be specified. |
| grdgradient |
Compute
directional derivative or gradient from .grd files. It
may be used to compute the directional derivative in a
given direction, or the direction and the magnitude of
the vector gradient of the data. |
| grdinfo |
Get
information about the contents of 2D .grd files, it reports
various statistics for the (x,y,z) data in the grdfile.
The output information contains the minimum/maximum values
for x, y, and z, where the min/max of z occur, the x/y
increments, and the number of x and y nodes, and (optionally)
the mean, standard deviation, and/or the median, L1 scale
of z, and number of nodes set to NaN. |
