gistfile1.txt

Python:
from shogun.Features import RealFeatures
from numpy import array, float64, all

# create dense matrices A,B,C
matrix=array([[1,2,3],[4,0,0],[0,0,0],[0,5,0],[0,0,6],[9,9,9]], dtype=float64)

parameter_list = [[matrix]]

# ... of type LongInt
def features_simple_real_modular(A=matrix):
  
# ... of type Real, LongInt and Byte
    a=RealFeatures(A)

# print some statistics about a
#print a.get_num_vectors()
#print a.get_num_features()

# get first feature vector and set it
#print a.get_feature_vector(0)
    a.set_feature_vector(array([1,4,0,0,0,9], dtype=float64), 0)

# get matrix
    a_out = a.get_feature_matrix()
    print a_out

    assert(all(a_out==A))
    return a_out


if __name__=='__main__':
    print 'simple_real'
    features_simple_real_modular(*parameter_list[0])

result:
[[ 1. 2. 3.]
 [ 4. 0. 0.]
 [ 0. 0. 0.]
 [ 0. 5. 0.]
 [ 0. 0. 6.]
 [ 9. 9. 9.]]


lua:
require 'shogun'

matrix = {{1,2,3},{4,0,0},{0,0,0},{0,5,0},{0,0,6},{9,9,9}}

parameter_list = {{matrix}}

function features_simple_real_modular(A)
a=RealFeatures(A)
a:set_feature_vector({1,4,0,0,0,9}, 0)
    
a_out = a:get_feature_matrix()
for _,row in ipairs(a_out) do for _,cell in ipairs(row) do io.write(cell..' ') end io.write('\n') end
    
return a_out
end

if debug.getinfo(3) == nill then
  print 'simple_real'
features_simple_real_modular(unpack(parameter_list[1]))
end

1 4 0
0 0 9
0 0 0
0 5 0
0 0 6
9 9 9