GSL_Vector class
Class methods
GSL_Vector.GSL_Vector.new(argv)GSL_Vector.GSL_Vector.alloc(argv)-
These methods create a GSL_Vector object. With an integer, a vector object is initialized in a given size,
require 'gsl' v = GSL_Vector.new(10) ( 'alloc' is also available )
Vector elements will be set with the 'set' method.
One can create a vector giving an array, as
v = GSL_Vector.new([1, 2, 3])
The size of the vector created is the same of the given array.
GSL_Vector.GSL_Vector.calloc(size)-
This method creates a vector object, and initializes all the elements to zero.
Methods
GSL_Vector#get(i)-
This returns the i-th element of the reciever vector. The [] method is also available.
p v.get(2) p v[2]
GSL_Vector#set(argv)-
This method sets the value of the elements of the vector object. With two arguments as (i, x), where i is an integer and x is a number, the i-th element of the vector is set to x.
v.set(2, 3.5) # v[2] = 3.5
One can give an array to set elements, as
v.set([1.2, 4.6, 6])
The size of the array given must be smaller than that of the vector.
GSL_Vector#set_all(x)-
This method sets all the elements of the vector to the value x.
v.set_all(3.5)
GSL_Vector#set_zero-
This method sets all the elements of the vector to zero.
GSL_Vector#set_basis!(i)-
This method makes a basis vector by setting all the elements of the vector to zero except for the i-th element which is set to one. For a vector v of the size 10, the method
v.set_basis!(4)
sets the v itself to a basis vector [0, 0, 0, 0, 1, 0, 0, 0, 0, 0]. Note that the vector v is modified.
GSL_Vector#set_basis(i)-
This method returns a basis vector by setting all the elements of the vector to zero except for the i-th element which is set to one. For a vector v of the size 10, the method
vb = v.set_basis(4)
creates a new vector vb with elements [0, 0, 0, 0, 1, 0, 0, 0, 0, 0]. The vector v is not changed.
GSL_Vector#each-
An iterator for each vector element.
v.each do |x| p x end
GSL_Vector#print-
Show all the elements of the vector in %4.3e format.
GSL_Vector#fprintf(io, format)-
This method writes the vector elements line-by-line to the io object io using the format specifier format. One doesn't have to use this method in a loop to print each data to the file.
GSL_Vector#fscanf(io)-
This method reads formatted data from the io object io into the vector, as
v = GSL_Vector.new(15) f = File.open("smpv.dat") v.fscanf(f) f.close v.printf("%f")The method printf is equivalent to a call of the method fprintf with an argument stdout, as
v.fprintf(stdout, "%f"). The fscanf method uses the size of the vector to determine how many numbers to read. GSL_Vector#clone-
This method creates a new vector of the same elements.
GSL_Vector#swap_elements(i, j)-
This method exchanges the i-th and j-th elements of the vector in-place.
GSL_Vector#reverse-
This method reverses the order of the elements of the vector.
Vector operations
GSL_Vector#add!(b)-
This method adds the elements of vector b to the elements of vector self. The receiver self is modified in place. The two vectors must have the same length.
GSL_Vector#add(b)-
This method adds the elements of vector b to the elements of the vector self, and returns a new vector. The vector self is not changed.
GSL_Vector#sub!(b)-
This method subtracts the elements of vector b from the elements of vector self. The two vectors must have the same length. The vector self is modified in place.
GSL_Vector#sub(b)-
Same as GSL_Vector#sub!(b), but not modifies the reciever, and returns a new vector.
GSL_Vector#mul!(b)-
This method multiplies the elements of vector self by the elements of vector b. The two vectors must have the same length. The reciever self is modified.
GSL_Vector#mul(b)-
Same as GSL_Vector#mul!(b), but not modifies the reciever, and returns a new vector.
GSL_Vector#div!(b)-
This method divides the elements of vector self by the elements of vector b. The two vectors must have the same length. The reciever self is modified.
GSL_Vector#div(b)-
Same as GSL_Vector#div!(b), but not modifies the reciever, and returns a new vector.
GSL_Vector#scale!(x)GSL_Vector#scale(x)-
This method multiplies the elements of vector self by the constant factor x.
GSL_Vector#add_constant!(x)GSL_Vector#add_constant(x)-
This method adds the constant value x to the elements of the vector self.
Finding maximum and minimum elements of vectors
GSL_Vector#max-
This method returns the maximum value in the reciever vector.
GSL_Vector#min-
This method returns the munimum value in the reciever vector.
GSL_Vector#minmax-
This method returns an array of two elements, the minimum and the maximum values in the vector self.
GSL_Vector#max_index-
This method returns the index of the maximum value in the vector. When there are several equal maximum elements then the lowest index is returned.
GSL_Vector#min_index-
This method returns the index of the minimum value in the vector. When there are several equal minimum elements then the lowest index is returned.
GSL_Vector#minmax_index-
This method returns an array of two elements which has the indices of the minimum and the maximum values in the vector self.
===
GSL_Vector#to_a-
This method converts the vector into a Ruby array. A Ruby array also can be converted into a GSL_Vector object with the to_v method. For example,
v = GSL_Vector.alloc([1, 2, 3, 4, 5]) v.print -> 1.0000e+00 2.0000e+00 3.0000e+00 4.0000e+00 5.0000e+00 a = v.to_a -> GSL_Vector to an array p a -> [1.0, 2.0, 3.0, 4.0, 5.0] a[2] = 12.0 v2 = a.to_v -> a new GSL_Vector object v2.print -> 1.0000e+00 2.0000e+00 1.2000e+01 4.0000e+00 5.0000e+00
GSL_Vector#to_naGSL_Vector#to_narrayGSL_Vector#to_NArray-
This method converts a GSL_Vector object into an NArray object. An NArray object is also converted into a GSL_Vector object with the method to_v or to_gv.
ex) require 'narray' require 'gsl/gsl_array' # GSL_Vector v = GSL_Vector.new([1, 2, 3, 4]) p v <---- [ 1.000e+00 2.000e+00 3.000e+00 4.000e+00 ] #<GSL::GSL_Vector> # NArray na = v.to_na p na <---- NArray.float(4): [ 1.0, 2.0, 3.0, 4.0 ] # GSL_Vector v2 = na.to_gv <---- GSL_Vector objectTo enable this, one should compile Ruby/GSL with the option flag with-narray-include=....