Functions and commands 395
head Returns the first element of a given vector, sequence or string.
head(Vector) or head(String) or
head(Obj1, Obj2,…)
Example:
head(1,2,3) gives 1
Heaviside Returns the value of the Heaviside function for a given real
number (i.e. 1 if x>=0, and 0 if x<0).
Heaviside(Real)
Example:
Heaviside(1) gives 1
hyp2exp Returns an expression with hyperbolic terms rewritten as
exponentials.
hyp2exp(Expr)
Example:
hyp2exp(cosh(x)) returns
iabcuv Returns [u,v] such as au+bv=c for three integers a,b, and c.
Note that c must be a multiple of the greatest common divisor
of a and b for there to be a solution.
iabcuv(Intgra, Intgrb, Intgrc)
Example:
iabcuv(21,28,7) gives [-1,1]
ibasis Given two matrices, interprets them as two vector spaces and
returns the vector basis of their intersection.
ibasis(Matrix1, Matrix2)
Example:
ibasis returns [-1,-1,0]
icontent Returns the greatest common divisor of the integer coefficients
of a polynomial.
icontent(Poly,[Var])
Example:
icontent(24x^3+6x^2-12x+18) gives 6
exp x
1
exp x
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+
2
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