NAME

M_math(3fm) - [M_math::INTRO] module collecting various general math-related procedures

DESCRIPTION

GEOMETRY

• citer(3f) determine various geometric properties of circle segment given radius and area of the segment.
• envelope(3f) Find the vertices (in clockwise order) of a polygon enclosing the points (x(i), y(i), i=1, ..., n.
• inpolygon(3f) Subroutine to determine whether or not a point is in a polygon
• locpt(3f) find if a point is inside a polygonal path
• poly_intercept(3f) find points where a line intersects a polygon
• polyarea(3f) find area of a polygon
• closest(3f) find point in arrays closest to target point
• hypot(3f) Euclidean distance

FIT

• julfit(1f) linear least square fit
• julfit1(3f) linear least square fit(y=a*x+b)
• lowess(3f) data smoothing using locally weighted regression
• splift(3f) fits a spline to the n data points given in x and y
• splint(3f) interpolates and twice differentiates a cubic spline
• linearint(3f) linear interpolation

STATISTICS

• bds(3f) basic descriptive statistics
• ncr(3f) number of unique combinations of size R from set of N candidates
• extremum(3f) find the minimum and maximum value in a real array
• stddev(3f) standard deviation
• skekurx(3f) skew and kurtosis variant
• skekur1(3f) skew and kurtosis variant

COMPARING AND ROUNDING FLOATING POINT VALUES

• accdig(3f) compare two real numbers only up to a specified number of digits
• almost(3f) compare two numbers only up to a specified number of digits
• dp_accdig(3f) compare two double numbers only up to a specified number of digits
• in_margin(3f) check if two reals are approximately equal using a relative margin
• round(3f) round val to specified number of significant digits
• scale1(3f) given xmin,xmax,n, find new range xminp xmaxp divisible into approximately n linear intervals of size dist
• scale3(3f) find nice log range, typically for an axis

MATRICES

• invert_2x2(3f) directly invert 2x2 matrix
• invert_3x3(3f) directly invert 3x3 matrix
• invert_4x4(3f) directly invert 4x4 matrix
• magic_square(3f) fill a magic square

POLYNOMIALS

• quadratic(3f) return roots of quadratic equation

CURVE FITS TO FUNCTIONS

• gcsgau1: solve a system of simultaneous linear equations
• glstsq: least squares fit to a polynomial expression

THE CALCULUS

• qhfg: compute vector of integral values for given general table
• qhsg: compute vector of integral values for given general table
• qtfg: compute vector of integral values for given general table
• trapezoidal_integral: compute vector of integral values for given general table