C.1 Functions

Many model parameters can be defined via mathematical expression. This appendix documents the syntax of this capability.

The following functions are currently supported.

sin(x) The sine function.

cos(x) The cosine function

tan(x) The tangent function

csc(x) The cosecans function

sec(x) The secans function

cot(x) The cotangent function

acos(x) The arccosine function

asin(x) The arcsine function

cosh(x) The hyperbolic cosine function

sinh(x) The hyperbolic sine function

tanh(x) The hyperbolic tangent function

ln(x) The natural logarithm

log(x) The logarithm with base 10

exp(x) The exponential function

sqrt(x) The square root function

abs(x) The absolute value function

sgn(x) The sign function

H(x) The Heaviside function (x = 0.5 at zero)

step(x) The right-continuous unit step function

J0(x) Bessel function of the first kind, order 0

J1(x) Bessel function of the first kind, order 1

Jn(x,n) Bessel function of the first kind, order n

Y0(x) Bessel function of the second kind, order 0

Y1(x) Bessel function of the second kind, order 1

Yn(x,n) Bessel function of the second kind, order n

sinc(x) The sinc function (i.e. sin(x)/x)

fac(n) The factorial of n

erf(x) The error function

erfc(x) The complementary error function (erfc(x) = 1 - erf(x))

tgamma(x) The Gamma function

atan2(x,y) The two-parameter arctangent function

pow(x,y) The y-th power of x

Tn(n,x) The Chebyshev polynomial of order n

binomial(n,m) The binomial of (n,m)

max(x1,...,xn) Returns the maximum value of the values listed

min(x1,...,xn) Returns the minimum value of the values listed

avg(x1,...,xn) Returns the average value of the values listed