11.13 Math Routines

These return values of mathematical functions or otherwise perform mathematical tasks.

abs

The absolute value or magnitude.

cbrt

The cube root.

crosscorr

The cross-correlation.

distr

To distribute data to particular elements of an array.

dsum

To sum in double type.

fsum

To sum in float type.

getmin9

To determine the minimum from a fit to 3-by-3 elements.

gridmatch

To determine displacements between two images.

hist

To get a histogram.

histr

To get a normalized histogram.

max

The maximum.

maxfilter

A running maximum (with a fixed window size).

mean

The average.

medfilter

A running median (with a fixed window size).

min

The minimum.

minfilter

A running minimum (with a fixed window size).

not

The logical opposite (zero versus non-zero).

one

To one

poly

A polynomial.

psum

A sum weighted with specified powers of the coordinates.

regrid

To interpolate unto a different coordinate grid.

regrid3

To interpolate unto a different coordinate grid.

root3

To calculate roots of third-degree polynomials.

runcum

A running sum (with a fixed window size).

runsum

A running sum (cumulative).

scale

Linear scaling to byte type.

sdev

Standard deviation.

sqrt

Square root.

stretch

To distort according to displacement data.

subshift

To shift over a fractional number of pixels.

subshiftc

To shift over a fractional number of pixels.

total

To sum.

voigt

The Voigt function.

zero

To zero.

zinv

Inverse (one-over) protected against division by zero.