GSL::Function class

Class Methods

GSL::Function.new

GSL::Function.alloc

Constructor for an instance of the Function class.

• ex:

  require 'gsl'
  include GSL
  f = GSL::Function.new { |x| sin(x) }

The value of the function is evaluated by the method eval, as

p f.eval(x)

The function can have constant parameters of arbitrary numbers. Here is an example in case of exponential function f(x; a, b) = a*exp(-b*x).

f = Function.new { |x, params|    # x: a scalar, params: an array
  a = params[0]
  b = params[1]
  a*exp(-b*x)
}

To evaluate the function f(x) = 2*exp(-3*x),

f.set_params(2, 3)
f.eval(x)

Methods

GSL::Function#eval(x)

GSL::Function#call(x)

GSL::Function#[x]

These methods return a value of the function at x.

p f.eval(2.5)
p f.call(2.5)
p f[2.5]

GSL::Function#set { |x| ... }

GSL::Function#set(proc, params)

This method sets or resets the procedure of self, as

f = GSL::Function.new { |x| sin(x) }
p f.eval(1.0)               <- sin(1.0)
f.set { |x| cos(x) }
p f.eval(1.0)               <- cos(1.0)

GSL::Function#set_params(params)

This set the constant parameters of the function.

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