I am new to Julia. I have 2 questions about constructting sparse matrix from arrays.
1. I=[1;1;2] J=[1;1;2] V=[1.0;1.0;1.0] Mat=sparse(I,J,V,2,2) According to the Julia guide "If the combine function is not supplied, duplicates are added by default." I expect Mat to be [ 1, 1] =1.0 [ 1, 1] = 1.0 [2, 2] = 1.0 however, what I get is [1,1]=2 [2,2]=1 So what is the default behavior without combine function? How do I specify the combine function? There is no instructions about it right now. 2. when i change V=[1.0;0.0;0.0]. I expected [ 1, 1] = 1.0 [2, 2] = 0 what I get is [1,1]=1 How can I let julia to combine elements only according to the indexes I, J ? How to keep those elements with value 0 ? Thanks in advance. Yankai
