### 2.3. `igraph_nonlinear_barabasi_game` — Generates graph with non-linear preferential attachment

```int igraph_nonlinear_barabasi_game(igraph_t *graph, igraph_integer_t n,
igraph_real_t power,
igraph_integer_t m,
const igraph_vector_t *outseq,
igraph_bool_t outpref,
igraph_real_t zeroappeal,
igraph_bool_t directed);
```

This function is very similar to `igraph_barabasi_game()`, only in this game the probability that a new vertex attaches to a given old vertex is not proportional to the degree of the old node, but some power of the degree of the old node.

More precisely the attachment probability is the degree to the power of `power` plus `zeroappeal`.

This function might generate graphs with multiple edges if the value of `m` is at least two. You can call `igraph_simplify()` to get rid of the multiple edges.

Arguments:

 `graph`: Pointer to an uninitialized graph object, the generated graph will be stored here. `n`: The number of vertices in the generated graph. `power`: The power of the preferential attachment. `m`: The number of edges to generate in each time step, if the `outseq` parameter is a null vector or a vector with length zero. It is ignored otherwise. `outseq`: The number of edges to generate in each time step. For directed graphs this is exactly the out-degree of the vertices. The first element of the vector is ignored. If this is a null vector or a vector of length zero then it is ignored and the value of the `m` argument is used. `outpref`: Logical constant, if TRUE then the preferential attachment is based on the total degree of the nodes instead of the in-degree. `zeroappeal`: Positive number, the attachment probability for vertices with degree zero. `directed`: Logical constant, whether to generate a directed graph.

Returns:

 Error code.

Time complexity: O(|V|*m*log(|V|)+|E|), |V| is the number of vertices, |E| is the number of edges and m is the average number of edges added in a time step.

 `igraph_barabasi_game()` for the slightly more efficient implementation of the special case `power`=1.