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: air_pressure.m
    path of file: ./repos/CDT/cdt
    
    the code of the file until where you have to start completion: function P = air_pressure(h)
% air_pressure computes pressure from the baromometric forumula for a US Standard Atmosphere. 
% 
%% Syntax
% 
%  P = air_pressure(h)
% 
%% Description
%
% P = air_pressure(h) returns the pressure P in pascals corresponding to
% the heights h in geometric meters above sea level.
% 
%% Examples 
% For examples, type 
% 
%  cdt air_pressure

    
function P = air_pressure(h)
% air_pressure computes pressure from the baromometric forumula for a US Standard Atmosphere. 
% 
%% Syntax
% 
%  P = air_pressure(h)
% 
%% Description
%
% P = air_pressure(h) returns the pressure P in pascals corresponding to
% the heights h in geometric meters above sea level.
% 
%% Examples 
% For examples, type 
% 
%  cdt air_pressure
% 
%% Reference
% The barometric formula uses a 7 layer formula (8 layers if you include
% invalid heights above 86 km) for the 1976 US Standard Atmosphere. 
% https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770009539_1977009539.pdf
% updated link: https://www.ngdc.noaa.gov/stp/space-weather/online-publications/miscellaneous/us-standard-atmosphere-1976/us-standard-atmosphere_st76-1562_noaa.pdf 
% 
%% Author Info 
% This function was written by Chad A. Greene of the University of Texas at
% Austin, 2018. 
% 
% See also air_density.

%% Error checks: 

if any(h>86e3)
   warning('Returning NaNs for altitudes greater than 86 km.')
end