You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: pois_inv.m
    path of file: ./repos/malini/Codes/FC_EC_calculation code/DynamicFC/jplv7/distrib
    
    the code of the file until where you have to start completion: function pinv = pois_inv(x,l)
% PURPOSE: computes the quantile (inverse of the cdf) at x
% of the Poisson distribution with parameter lambda
%---------------------------------------------------
% USAGE:    inv = pois_inv(x,lambda)
% where:    x   = variable vector (nx1)
%        lambda = value at which to evaluate pdf 

    
function pinv = pois_inv(x,l)
% PURPOSE: computes the quantile (inverse of the cdf) at x
% of the Poisson distribution with parameter lambda
%---------------------------------------------------
% USAGE:    inv = pois_inv(x,lambda)
% where:    x   = variable vector (nx1)
%        lambda = value at which to evaluate pdf 
%---------------------------------------------------

% Author: Kurt Hornik
% <Kurt.Hornik@ci.tuwien.ac.at>
% Copyright Dept of Probability Theory and Statistics TU Wien
% Converted to MATLAB by JP LeSage, jpl@jpl.econ.utoledo.edu, 10/98


  if (nargin ~= 2)
    error('pois_inv: Wrong # of arguments');
  end